 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Car Forum / Chrysler Cars / February 2007a604 Limp, Rebuilt, Sensors replaced, solenoid replaced still Limps!
Hello, Hello, I picked up a Dodge stratus (95) with 75,000 miles. I put about 5-6k on it. Then one day (a very warm day) on the way home from work (40 mile commute) as i was nearing the house it shifted into what I thought may be limp mode at about 45-50mph. The car nose dived and started compression breaking after what felt like an inital total loss of power. I took it the las mile home and tried it after it cooled down, it went into limp after it warmed back up. So I took it to the dealership. They told me the Input and output speed sensors were bad and needed replacing as well as the Throttle Position Sensor. Not having the $500+ they wanted to do it I took the car home and replaced the input and outpust speed sensors myself. I drove the car and all seemed fine, so I took it to work the following day. On the way to work I was on the freeway and it was doing fine about 65mph. Then it dropped into limp. I was able to get the car the remainder of the way to work in limp. At lunch time the car did fine, no problems. However after work it would not go into 2nd gear so an expensive tow home. I then called a local chain tranny shop, they said they could rebuild the trans for about $1800, I had the car towed over and the problems began. By thursday they said the car was ready. I asked if they test drove it and they stated yes. I paid for the repair and left with the car, and made it about 3 blocks before it went into limp. I took it back. To make a long story short; They rebuilt the thranny for $1800 It still goes into limp when it reaches a hot operating temp. They say the dropping into limp has again fried the 2nd gear clutches. The have also replaced the sh.t solenoid and both input and output speed sensors as I had. They remain convinced of it being wiring, I'm not sure because it seems heat related. The TCM sometime over the life of the car has been replaced with a remanuf moapr unit. After a brief wiat for their diagnostic computer he hooked it up, had some problems getting any readings and finally got code 54 out of it. Well they had just put new speed sensors in it and so had I before them!!!! So he left the diag computer hooked up and took it for a ride. He cam back 15 mins later, pulled in and hollered for his partner to come take a ride. He "had never seen anything act like this before". They took it out after resetting the codes and about 35 mins later came back. He said it was the damnedst thing, that what was happening wasnt exactly limp mode. But more like a flat out stall and then a drop into limp mode. Which pretty much describes it. To me it feels like your crusing along at say 65, then all of the sudden the car nose dives, has no power, and after about 1-3 seconds the RPMs kick way up as the transmission catches its downshift. So to me its like coast starting a car on a hill get coasting at a good speed and pop the clutch. They say the abuse it got test driving has fried the new clutches they just put in it so it will need another rebuild(under warranty). But they have no idea what the problem could be. They have now replaced the solenoid pack and that didnt help. The TCM on the car is not the factory one but a mopar reconditioned unit so I know that the previous car owner had replaced that at least once too. They are currently convinced that wiring is an issue and are trying to find the problem now that they have a schematic. I've suggested they replace the TCM and despite the fact I am willing to pay for the part they dont want me to have to pay for that if it isnt the problem. I'm at a loss, my wife wants me to dispute the charge with my credit card company and try to get the car back and take it elsewhere but in light of the problems I'm not sure anyone else would have any better luck. Are there any suggestions you have? Some insight? Help! > Hello, > [quoted text clipped - 71 lines] > > Help! Does your Stratus have the V6? There was a post on this newsgroop a few weeks back about a hard-to-troubleshoot stalling problem on an early JA car with a V6. Turned out to be a wiring problem that cause additional problems. I would suggest searching the NG. I will try to find it too. -KM I found it. Search for this: "1995 Cirrus 2.5L stall condition" It is a lot of reading, but it would not hurt to check. -KM >I found it. Search for this: > >"1995 Cirrus 2.5L stall condition" Thanks, I read through the thread and its not very reassuring and I dont see a final resoloution either. I have gotten one other tip that it could be the Zener Diode on the AC Clutch going bad and allowing a spike to return through the harness causing all the shift solenoids to actuate/activate at once. I passed that information on to the transmission shop this morning. No word from them yet on any progress. My next car will be a 74 Dodge Dart, it was my first car and there wasnt anything on it short of the rearend that I couldnt tackle in a weekend. Or maybe another 69 300 with aftermarket fuel injection installed on its 440 again, 20MPG on that beast wasnt bad.. >Hello, > >I picked up a Dodge stratus (95) with 75,000 miles. Well so much for that. I got tired of waiting for results so I called the transmission shops corporate office and complained about 9 days with no end in sight. They contacted the shop and within an hour they called my house and told my wife that my car was ready. Flabergasted I called them and asked if they fixed the limp mode problem. The guy said "Your transmission is fixed." I said yea but will it go into limp? he said "Your transmission is fixed, if you have a problem with a sensor or a control thats not my area. I fix tranmissions. I dont have diagnostic equipment for other parts of cars" So tomorrow I get to go pickup my car with its twice rebuilt tranmission and still existing limp mode problem that the shop refuses to fix or accept resposibility for. So I have paid $1800+ for a repair that wont last if the transmission screws up again and I am willing to bet thats how they will weasel out of their warranty. So now I am really looking for any last ditch ideas.... Thanks... >>Hello, >> [quoted text clipped - 19 lines] > > Thanks... Hi... You have my sympathy... Just one thought fwiw from an old retired electrical guy, if it should be at all helpful? How about using another car (trade with your wife, or child, or...) for your highway speed trip to work - and let whichever of the above use yours for in city slower trips while you work out what's really going wrong. That way if it does decide to shift to a lower gear (or all gears) you'll (they'll) have a much better chance of not cooking the clutches because of the lower speed. Take care. Ken >Hi... > [quoted text clipped - 15 lines] > >Ken Thank you Ken its good advice but unfortunately I am lucky enough to own a house in the boonies. I live in a rural area where I have .5 mile to the left and right of my drive way thats 35mph after that its 45+ and to get to any town its all highway driving. My wife has a Accord I have been using while mine was in the shop so I stranded her at home with our 4yr old for the last 2 weeks. I plan as soon as I recover from this nightmare on buying a 60's or 70's car for a spare. Mileage may not be as good but getting from point a to point b will suffice. Take it easy! > Thank you Ken its good advice but unfortunately I am lucky enough to > own a house in the boonies. I live in a rural area where I have .5 [quoted text clipped - 8 lines] > > Take it easy! As a last resort, take the car to the dealer and have the software revision code on the TCM checked. Make sure the revision code is the latest possible for this car. The dealer can flash the EEPROM as needed. This is relatively inexpensive, from below $70 to $130 if they charge for getting the revision number first. It's a long shot and it's just a start. A bug or a bad byte in the EEPROM can do things that can damage the car. The reman TCM that was put in might not have the latest code. You would think this would be checked but it requires hooking the TCM up to a reader which takes time and effort. In my vehicle with the A604, the electronically controlled clutch upshifted too slowly with the original code. So the torque converter started to self-destruct, exhibiting a shudder around 37 to 45 mph. I had ATF +3 put in after a simple drain and a new filter and a reprogramming of the computer and all is well with the tranny. I stayed away from ATF +4 on purpose since it might be too "slippery" for the A604. I'm not a mechanic and don't know much about this stuff but just throwing out a wild suggestion for you. Reman. Part No. Vehicle Application - Software ID Year Body Type Engine R4686606AA 04686606 95 AJ,AS,A1,A3,A4,ES 3.0, 3.3 & 3.8L R5269726AA 05269726 95 FJ 2.0 & 2.5L R4797708AA 04797708 95 LH 3.3 & 3.5L R4686478AA 04686606 93-94 A,C,J,P,S,Y 3.0, 3.3 & 3.8L R4759066AA 04797708 93-94 LH 3.3 & 3.5L R4761848AA 04796123 92 A,C,G,J,S,Y 3.0L R4761849AA 04796124 92 C,S,Y 3.3L & 3.8L R4761847AA 04796122 90-91 C,S,Y 3.3 & 3.8L R4761846AA 04796121 89-91 A,C,G,J,S,Y 3.0L >As a last resort, take the car to the dealer and have the software >revision code on the TCM checked. Make sure the revision code is the [quoted text clipped - 32 lines] >R4761847AA 04796122 90-91 C,S,Y 3.3 & 3.8L >R4761846AA 04796121 89-91 A,C,G,J,S,Y 3.0L Thanks! So in order to do the version check and re-flash does the TCM have to be removed from the vehicle, or can it be rather? If my car goes into limp tomorrow this may be my best resoloution for having the TCM checked. > >As a last resort, take the car to the dealer and have the software > >revision code on the TCM checked. Make sure the revision code is the [quoted text clipped - 37 lines] > goes into limp tomorrow this may be my best resoloution for having the > TCM checked. On my minivan, I assumed, perhaps wrongly, that only a special cable needed to be used, an expensive cable for pre-1996 vehicles. So that leaves out a lot of independents who might not wish to bother with this expense. The TCM sits plainly in site so I thought, aha, just unplug it and plug in the harness for the EEPROM reader and writer. It did not appear to me that the TCM had been unscrewed and taken out but I did not see what took place at the dealership. Not sure if the details are in the FSM. There is also a very inexpensive shop manual for this transmission, available directly from DC online or by phone, maybe most dealers' parts departments still can get it, for less than $20. A superbook for this tranny. I don't have it but just throwing out ideas for you. Also check, if not already, the TSB's on your car and tranny. A literature review, if you will. What I mentioned above with software revision numbers is directly from a TSB on this tranny. 1989-1998 41 TE/AE TRANSAXLE SUPERBOOK $17.00 http://www.techauthority.daimlerchrysler.com/ 800-890-4038 8am-8pm With some luck, the reprogramming might sort out the TCM if it were the TCM. > > >As a last resort, take the car to the dealer and have the software > > >revision code on the TCM checked. Make sure the revision code is the [quoted text clipped - 42 lines] > leaves out a lot of independents who might not wish to bother with this > expense. Most independents just buy "remanufactured" TCM's which are, as you probably can guess, nothing more than existing TCM's that have been cleaned up a bit and reflashed. > The TCM sits plainly in site so I thought, aha, just unplug it > and plug in the harness for the EEPROM reader and writer. It did not > appear to me that the TCM had been unscrewed and taken out but I did > not see what took place at the dealership. Not sure if the details are > in the FSM. They are not. You need scan tools that are prohibitively expensive (even used) for the DIYer. But in any case, his TCM is probably flashed already and if not, there's plenty of flashed ones in the wrecking yards. What's the part number on the side of it? Ted > >Hello, > > [quoted text clipped - 9 lines] > a sensor or a control thats not my area. I fix tranmissions. I dont > have diagnostic equipment for other parts of cars" The transmission sensor or control is -not- an "other part of the car" neither is the TCM, those are part of the transmission. > So tomorrow I get to go pickup my car with its twice rebuilt > tranmission and still existing limp mode problem that the shop refuses > to fix or accept resposibility for. So I have paid $1800+ for a repair > that wont last if the transmission screws up again and I am willing to > bet thats how they will weasel out of their warranty. If it fails again then dispute the charge through your credit card company and I will bet that you will win. Where did you take it? AAMCO? I never heard of a "transmission shop's corporate office" unless it was a national chain like AAMCO, and there's a reason that place is called SCAMCO by a lot of people. When you made the call to the corporate office, I am sure what happened was a telephone call from the corporate office to the local transmission shop that went something like this: corporate office: "Hey Joe, we got a call from this Richard Ahlquist saying you've been fooling with his car for 9 days what gives?" trans shop: "Yeah, it's really a tough one we think it's bad wiring and are trying to trace it out" corporate office: "how much warranty time have you put into this so far" trans shop: "about 5 hours over the last couple weeks" corporate office: "Joe, give the car back to the customer" trans shop: "but it's not fixed it will just break down again and the customer will bring it back" corporate office: "tell them it's not a problem in the transmission and not covered under warranty" trans shop: "then they are just going to dispute it and we will lose $1800" corporate office: "Joe, we have had this discussion before. Your cost to rebuild that transmission is about $300 in parts, and about $500 in labor. If they dispute the charge we lose $800, not $1800. And in the 5 hours you have spent trying to fix this, you could have rebuilt another customers car and made $1000. We lose less money by just accepting the $1800 chargeback and moving on then by you spending the time to try to fix it under warranty. Once they get a successful chargeback then they cannot make any further warranty claims and it will be someone else's problem" > So now I am really looking for any last ditch ideas.... Quit using lowball car repair places and find a good local independent transmission repair shop that has great ratings at the Better Business Bureau, and take it there. It will cost more than $1800 to rebuild - but it will get done properly. Your wife is right. And additionally, it probably IS the input and output speed sensors, or the connections to them. You, and SCRAMCO, both went out and bought cheapie speed sensors, didn't you, you didn't go get them from the dealer, right? And, did you replace the TPS sensor? Probably not, you were told that sensor was bad but you didn't mention replacing it. Well, why do you think that these sensors cost a lot more money at the dealer? Plenty of people have had the experience of buying cheap low-grade replacement sensors for this transmission and had the same experience as you, that has been talked about on this forum before. Ted > trans shop: "then they are just going to dispute it and we will lose $1800" > [quoted text clipped - 28 lines] > > Ted You make good points, Ted, which is usual for you. But why not a remanufactured transmission? The most expensive would be from DC and run now what, $1800? Labor would be additional. But that would come with a warranty for 3/36 would it not, including labor if the dealer put it in? There are cheaper reman or rebuilt trannies from jobbers which shops use and run about $1600? I don't know much about them. I recall a friend who had Cottman try to repair by rebuilding her tranny for $3000. At that time, a reman tranny from Chrysler was $1200, so with labor, what, $1800? She was not aware that in this case the dealer was far cheaper and probably far more competent. But in her case, the problem was not fully resolved until the TCM was updated. In any case, as a good mechanic told me, he would not rebuild his own. He would just get one from Chrysler and put it in. Too many parts, seals, and what not. But he was not a tranny guy but someone who specialized in European vehicles. >You make good points, Ted, which is usual for you. > [quoted text clipped - 14 lines] >and what not. But he was not a tranny guy but someone who specialized >in European vehicles. Actually I wound up at this shop because of a nasty shock from the dealer. I called them prior to getting the loan to fix the car, and asked "How much would you charge me to put a new transmission in this car?" Their reply, ballpark about $2200. So I got a loan for $2500. After I got my loan and called the dealer for the final pricing it was revealed the 2200 didnt inlclude labor. Final estimate was around $2780. I was kinda pissed at the jerking around. > Actually I wound up at this shop because of a nasty shock from the > dealer. I called them prior to getting the loan to fix the car, and [quoted text clipped - 4 lines] > revealed the 2200 didnt inlclude labor. Final estimate was around > $2780. I was kinda pissed at the jerking around. You don't have another dealer near you? I have two dealers near me. The one who got an outstanding signal at cartalk.com where they rate some shops and dealers and mechanics, did turn out to be outstanding. At least until they saw me as a chronic problem who would not dump money on the desk. I wish I could fellows. The other dealer was hit or miss. When I drove to them with a serious problem, they could not be bothered. Get an appointment. At other times, another service writer, would actually come out to the vehicle in the lot for a quick look and free advice. So very uneven. I am not surprised you got two quotes and messed around. That happens when you have a good cop bad cop routine in the dealership. It's a pain to get everything in writing, especially in the boonies where a word should be good enough. In your case, a mechanic friend could have ordered the tranny from the dealer at presumably reduced cost. I might have told the dealer that to get the price down to the original estimate or you'll purchase the tranny with the good customer 10% discount. In any case, that is bad enough to warrant a complaint. That's like a bait and switch fraud routine; it's along the same lines or just plain incompetence or greed or all three. Hi there, I have a 96 Sebring convertible 2.5l with an A604 trans. I seems to have the exact same problem. I did a little on the roa diagnosis and found that at exactly 67mph the engine would drop down t idle as if the cruise control was shutting it down. The car function completely normally from 0 to 67. Even if I speed up and coast to speed above 67 the engine returns to idle. As soon as the speed drop below 65 the engine returns to normal. People telling you that th transmission is fine may be on the right track. Because no matter wha I put my transmission through everything remains normal provided th speed is kept under 67mph. Note the fact that if you keep the gas peda floored when the engine kicks off at 67 the car abruptly springs back t life at the exact time the speed drops under 65. This is not recommende due to the fact that you may hurt a perfectly good transmission. I hav a pretty good repair manual and it expressly implies not to intermi computers with transmissions from different years, though specifics ar not mentioned. I have since parked the car and stripped it of all th important parts for use on a 98 that I picked up. I understand th frustration, I also live in a rural area and drive 35 miles to wor each way. For what it is worth you are not alone. At least you kno the problem has happened to someone else and is not a totally isolate incident. One good benefit was that on more than one occasion th problem saved me from getting caught in a speed trap... -- Jetwrench77 >The transmission sensor or control is -not- an "other part of the car" >neither >is the TCM, those are part of the transmission. Preaching to the choir here! I agree. >If it fails again then dispute the charge through your credit card company >and I will bet that you will win. Where did you take it? AAMCO? >I never heard of a "transmission shop's corporate office" unless it was >a national chain like AAMCO, and there's a reason that place is called >SCAMCO by a lot of people. No its not AAMCO, its a smaller chain I will name after I get my car back this morning. >> So now I am really looking for any last ditch ideas.... > [quoted text clipped - 15 lines] >for this transmission and had the same experience as you, that has >been talked about on this forum before. Thanks Ted. I'll keep this in mind, the sesnors I bought were Standard Automotive I believe, no they didnt come from the dealer. As for the TPS, no it hasnt been replaced, nor has the computer kicked another error code for it. Besides if the TPS was truly bad would there not likely be other throttle related symptoms? Richard, FWIW, there is a shop in my locality that completely rebuilds the A604 for $1495 + Tax. That is a rebuild of the trans. Sensors and other parts would be extra. And those prices are in Canadian Dollars. But they are a reputable shop! When I took my GC to them, they did NOT assume that it needed a rebuild, and as much as refused to do anything until they had performed a "proper and complete diagnosis". Their reasoning was that it could be many things, and they wanted to fix it right the first time. Which they did - it was a solenoid pack. All my wiring checked out OK. So Teds advice is correct. You need a local independant shop. Such shops live and die on reputation. They cannot aford to screw up and get a bad name. Check the BBB. Check with local automotive places. Often people "know" about the good, the bad, and the ugly of such shops. Ask around. If you get a farily consistant answers, and a good BBB rating, then that is your best bet. And as for your existing shop, I would dispute the charge - period. Start the process immediately. It takes time to get the paperwork, and for the process to complete. In the mean time, drive it close to home in your speare time to try and reproduce the problem. When you do (I am fairly certain) then drive it home in limp mode at lower speed. It should not damage the transmission. When mine went into limp mode my wife actually drove it for a few days before I drove it and noticed the limp mode! I then drove it over an hour away (at low speed on the highway! ;) to the excellent shop that fixed it properly. NO DAMAGE. GO kick some butt! I hate scaming auto shops! And, of course, once you get the car back please DO publish the name of the shop for all to see. Avoidence of such shops is a GOOD thing. hth >>The transmission sensor or control is -not- an "other part of the car" >>neither [quoted text clipped - 36 lines] >error code for it. Besides if the TPS was truly bad would there not >likely be other throttle related symptoms? > And as for your existing shop, I would dispute the charge - period. > Start the process immediately. It takes time to get the paperwork, and > for the process to complete. In the mean time, drive it close to home > in your speare time to try and reproduce the problem. When you do (I > am fairly certain) then drive it home in limp mode at lower speed. It > should not damage the transmission. It depends why it went into limp mode. If it's a sensor failure then it will not hurt the transmission. I had one of mine drop into 2nd gear while going 55Mph downhill on the freeway. The TCM had an input speed sensor code failure and I replaced the sensor that evening with one from NAPA. > GO kick some butt! I hate scaming auto shops! And, of course, once you > get the car back please DO publish the name of the shop for all to > see. Yes, definitely. As long as you stick exactly to the facts you cannot be sued for libel. Ted > Thanks Ted. I'll keep this in mind, the sesnors I bought were Standard > Automotive I believe, no they didnt come from the dealer. As for the > TPS, no it hasnt been replaced, nor has the computer kicked another > error code for it. Besides if the TPS was truly bad would there not > likely be other throttle related symptoms? A bad TPS is easy to see with an analog ohmmeter, just connected the ohmmeter to the TPS, move it slowly through the range of travel. The ohmmeter needle should track the movement exactly, if the needle jumps around particularly if it jumps when going back and forth over the same spot, the TPS is bad. What retailer did the sensors come from? Unfortunately these days you can't really blindly trust the brands, since many brand name companies manufacturer different levels of quality depending on the retailer that orders them. Ted >A bad TPS is easy to see with an analog ohmmeter, just connected the >ohmmeter to the TPS, move it slowly through the range of travel. The [quoted text clipped - 9 lines] > >Ted The sensors came from Advance auto parts. I hadnt thought to try an analog meter on the TPS, the Haynes manual I have shows no info on how to test it. Well I got the car back today from Speedy Transmission. The rebuild itself seems to be fine. I continue to work under the assumption that the advice someone emailed me after seeing my post here is correct. That tip was that they had in the past seen a similar problem to this and that it was the A/C compressor cycling off and creating an inductive spike in the electrical system. So after picking up the car i drove down the block some and stopped the car, got out and pulled the A/C compressor relay from under the hood. I then proceded to drive the car today without incident. The folks at speedy were shocked with the information I shared with them about the A/C and wanted to know where I got it so I pointed them to Google Groups (no sense trying to spend hours explaining newsgroups). Today was quite hot, 91 when I got home. Since the A/C was unhooked and will continue to be so until I get a zener diode to replace/supplement the old one I should get some good testing in to eliminate/validate the A/C being the source of the issue. All said and done today I put 100+ Miles on the car since picking it up with no further issue. I'd like to thank everyone in the group who chimed in, and the person who supplied what I hope is the answer to my issue! > Well I got the car back today from Speedy Transmission. The rebuild > itself seems to be fine. [quoted text clipped - 20 lines] > I'd like to thank everyone in the group who chimed in, and the person > who supplied what I hope is the answer to my issue! Richard, don't celebrate too quick, your tempting the daemons, you know. You don't need a zener diode, any old diode will do, all it is for is shorting out the back EMF that is generated when the clutch releases and the field in the clutch coil collapses. Any electrical supply house will have it. Just get the biggest wattage one you can fit in there. But be aware that if it's a failing sensor that the way they usually fail if they don't just go dead is to be very intermittent. You might have a limp incident every 3-6 months, then over time the interval between incidents becomes closer and closer. Ted >Richard, don't celebrate too quick, your tempting the daemons, you know. > [quoted text clipped - 11 lines] > >Ted Oh trust me with it being an intermittient problem I wont celebrate for a bit yet, I am just glad that its behaving. The diode I'm looking at is part of a GM harness repair kit and is at http://www.ecklers.com/product.asp?pf_id=44831&dept_id=1135 Other than the speed sensors are there any other sensors I need to be concerned with? I wish i still had my oscilliscope to watch for the spike but it went bye bye about 6 years ago and I just cant justify buying another. >>Richard, don't celebrate too quick, your tempting the daemons, you know. >> [quoted text clipped - 23 lines] >I wish i still had my oscilliscope to watch for the spike but it went >bye bye about 6 years ago and I just cant justify buying another. Where is this zener located in the A/C harness? I have a 94 Caravan that has the 41TE in it (A604) that is acting kinda funny. It's not to the extent of your problem, but for a few dollars (I probably have a few zeners in my parts box), it's one step to get past. >Where is this zener located in the A/C harness? I have a 94 Caravan >that has the 41TE in it (A604) that is acting kinda funny. It's not to >the extent of your problem, but for a few dollars (I probably have a >few zeners in my parts box), it's one step to get past. The one mechanic who has replied to me about this question indicates its either on the A/C compressor or actually in the cluth coil. One place I found this; http://www.dormanproducts.com/cgi-bin/vm91corp30r/item-dtl.w?sid=0x011cb8c6&item =84706&clt=hwrap1&vsrch_str=&vsrch_brand=&vsrch_cat=&st_amount=&end_amount=&star t=&vfrom=&prev=&vnext=&category_list=:0 havent had a chance to look at my compressor yet to see if that would work. Note that link is for a 95 stratus you will need to see if they have one for your van. >>Well I got the car back today from Speedy Transmission. The rebuild >>itself seems to be fine. [quoted text clipped - 36 lines] > > Ted Hi Ted... I'd respectfully suggest that you re-consider your suggestion to replace the existing zener with "any old diode" A zener <> any old diode. Take care. Ken > > Richard, don't celebrate too quick, your tempting the daemons, you know. > > [quoted text clipped - 22 lines] > > Ken Good job of figuring this out. Really tricky. Good discussion. I would like to ramble a little since we are now discussing analog and a touch of digital engineering in the automotive newsgroup. "Two (equivalent) Zeners in series and in reverse order, in the same package, constitute a transient absorber (or Transorb, a registered trademark). They are named for Dr. Clarence Melvin Zener of Southern Illinois University, inventor of the device." = Wikipedia. I vaguely remember this when I was building stuff and worried about spikes and surges. I gather the question here is allowing the signal through but not the spike or surge. How big is that signal? +5 volts? A Light Emitting Diode or LED would light up but that's a bit fancy. About the oscilloscopes, an analog might be fine here. I have seen even 100/200 MHz old Tektronix 'scopes going for very cheap and they will get the spike, yes? Now a good digital scope might what, record over a period so one could go eat supper and then come back. I'm wondering, maybe a dirt cheap signal probe might get it? Guess it's back to a good, fast digital 'scope because you might want to record and inspect the bugger at leisure. I guess if this signal or surge is that bad, then a small isolation transformer inserted here? That would be overkill but they really do the job. Nothing gets by a good isolation transformer, well, maybe a big lightning strike. Can you put one on a signal line though? Breadboard this to see if it works? Where's a good analog design engineer when you need one for a car? Most engineers are digital so look for the mature guys for the analog which is far more complicated than digital on a byte for spike basis :) >Good job of figuring this out. Really tricky. Good discussion. I would >like to ramble a little since we are now discussing analog and a touch [quoted text clipped - 27 lines] >engineers are digital so look for the mature guys for the analog which >is far more complicated than digital on a byte for spike basis :) Ahh my electronics coursework was over 15 years ago so I dont problaim to be not rusty ;) Basically the tip I got mentioned a plymouth breze that had the same issue. The dealer mechanic in question didnt post to the group so I am assuming he had his reasons. Basically he stated something to the effect that the collapse of the A/C compressor circuit could produce a spike as high as 600 volts. That in the case he saw it was literally spiking all the way back to the solenoids and activating them all. I'm going to err on the side of caution and get the zener since thats what was originally in the cicuit apparently. It all plays out very sensible to me that the zener could have been going bad through all of my limp incidents. Each time the car was hot, if the zener was going bad and opening while hot all it would have needed was one time for the A/C to cycle off and poof. So I guess I will go with the zener I mentioned earlier in the thread and for giggles I am replacing the AC relay in case this relay has its own zener (a lot of older bosch relays did I know). For less than $10 its cheap insurance. The car today did just fine again, not proof positive but it is encouraging especailly considering it was hotter today. > >>Well I got the car back today from Speedy Transmission. The rebuild > >>itself seems to be fine. [quoted text clipped - 43 lines] > > A zener <> any old diode. Yes, I know that. However there is really no need for a zener in this circuit. Most likely some engineer specced something like a 20 or so volt zener with the idea that it would be connected anode to positive and cathod to negative, and when the EMF collapsed in the clutch coil the zener would clip the hundred volt or so pulse. However, a regular diode connected anode to negative, cathod to positive, does the same job since when the EMF collapses it will flow backwards and in that case the diode looks like a direct short. Diodes are used in electronic circuits in parallel with relay coils all the time for exactly the same reason. A more specific explanation is here: http://experts.about.com/q/Electrical-Engineering-1356/Protection-Diode.htm I guess the Chrysler engineer that specced it was the same guy that wrote the question in the the electrical expert. ;-) Ted > > > You don't need a zener diode, any old diode will do, all it is for is > > > shorting [quoted text clipped - 39 lines] > > Ted That's a good discussion but let me ask something here. I think I understand some of your comments [it's been a while since I used zeners or regular diodes] in regards to the OP's problem involved. The OP fellow is looking at $2000 and possibly unable to get to work. Now a zener diode is what? It's been a while since I bought them, but from Digi-Key, I could buy 10 or 20 for a few dollars? Diodes are probably cheaper and simpler to understand. But when looking at thousands of dollars and the specter of not getting to work, why mess with a part that can be purchased often for loose change, like a quarter or now 50 cents, even at Radio Shlack? Nothing in my car costs that little except maybe a cap to the tire's air valve! I know, it's the challenge involved. Is there any condition under which a regular diode would be better than the zener diode? In this case, the zener is reversed to the regular diode if I followed your cathode/anode comment but the schematic or original usage calls for a zener, does it not? > ...Most likely some engineer specced something like a 20 or > so volt zener with the idea that it would be connected anode to positive [quoted text clipped - 3 lines] > the same job since when the EMF collapses it will flow backwards > and in that case the diode looks like a direct short... No. You're half right. Whether a zener or non-zener is used, it would be placed anode to negative, cathode to positive (keep in mind that the terminology for the zener terminals is for the forward - non-zener mode - conduction - same as a regular diode). Either diode would clamp negative spikes generated by the coil turning off - either the regular (non-zener) or the zener would be with anode to negative and cathode to positive - when the positive wire tries to go negative, the diode goes into foward conduction mode and clamps at just below the ground wire (around -1 volt depending on the current it is absorbing). With the zener reversed like you said, the positive wire voltage would be clamped to the forward conducting voltage (around +1 volt) when it was attempted to turn the coil on thus blowing the fuse for the driver circuit and/or damaging the driver. In reality, the Zener would never go into zener (reverse conduction) mode in this application. It does have the secondary benefit of clamping the positive wire to whatever the zener voltage rating is if a *positive* spike were to come in from elsewhere (but it won't come from this coil). But that's not why it was designed in for this application. The technical rationale for using a zener for a back-emf snubbing application is that they are, by design, optimized for *short* *duration* *high* *current* situations in a small package (internally mechanically and thermally designed for high *local* heating and electrical stresses), whereas a regular diode is rated for current under steady state conditions (high watts absorbed by thermal mass), and so if it were to have the same (short-duration) current capability as the zener's (short-duration) rating, it's package would be much larger, and more expensive. IOW - to get the same high current rating in a regular diode as what the zener can handle on a short-term basis, the regular diode would be larger (and for the high volume manufacturer) significantly more expensive. If you get a 600 volt 1 amp regular diode, it should work, but a 20 volt .5 or 1 watt zener would be preferred (and smaller). Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x') And don't forget to put a resistor in series with it.. ... the current spikes in any circuit of this type are enormous and will usually "smoke" a diode or zener in very short order. Something that will clamp the surge at the level the semiconductor can handle.. these spikes are VERY short and the "ring" fades fast so I would suspect 1 watt resistor would be enough.. Been many years since I have been involved in this stuff so.. YMMV. Ted > > ...Most likely some engineer specced something like a 20 or > > so volt zener with the idea that it would be connected anode to positive [quoted text clipped - 7 lines] > be placed anode to negative, cathode to positive (keep in mind that the > terminology for the zener terminals is for the forward - non-zener mode Damn, Bill, I suspected I had that screwed up. I could never remember current flow direction in a diode. > The technical rationale for using a zener for a back-emf snubbing > application is that they are, by design, optimized for *short* [quoted text clipped - 8 lines] > diode would be larger (and for the high volume manufacturer) > significantly more expensive. That one I did remember, which is why I said to get the biggest wattage you could fit in there. I think the cost difference is under $5 between the two, and I've always leaned toward massively derating replacement components that have failed on the assumption that if they had been properly sized in the beginning they wouldn't have failed. > If you get a 600 volt 1 amp regular diode, it should work, but a 20 volt > .5 or 1 watt zener would be preferred (and smaller). Only preferred if your manufacturing, where saving a buck or so on a component means a huge amount. Ted I had virtually the same experience with a late 90's Intrepid. Don't know what transmission model it was. But I could have your post for you. Car was under warranty. It spent 6 weeks on and off in the Chrysler dealership - it's fixed; it's broken; it's fixed; it's broken.... I even drove around for one weekend with the Chrysler "Co-Pilot" sitting on the passenger seat. Chrysler replaced all kinds of parts. In the end, the cause was high resistance on one pin in a multipin connector. They replaced that portion of the wiring Harness (connector and all) and that was the end of the problem. Phil > Hello, > [quoted text clipped - 71 lines] > > Help! Well #@$#$#@!$#@!!@#$ I left my house to come to work this morning and made it about 1 mile and it went into limp. It went into limp while i was coming to a stop at a stop sign. I stopped, shut the car off and restarted. It never went back into limp and I drove it all the way to wrok mostly on back roads. I tried the key trick for retrieving error codes (on-off-on ....etc) and got nothing at all. So as it sits its more intermittient than it was before but its still limping. The only thing totally different today than any other time was it was cool, in the 60's and there was heavy dew this morning. Is there any way to 100% find out what caused it to go into limp? Last time the computer didnt show any codes. If it were youre car what would you start with replacing at this point? The TCM? Wiring? The A/C is still disabled so i guess that wasnt the whole problem. >Well #@$#$#@!$#@!!@#$ > [quoted text clipped - 6 lines] >I tried the key trick for retrieving error codes (on-off-on ....etc) >and got nothing at all. The "key trick" only allows you to read codes from the ENGINE computer. The transmission computer is completely different. >So as it sits its more intermittient than it was before but its still >limping. [quoted text clipped - 8 lines] >point? The TCM? Wiring? The A/C is still disabled so i guess that >wasnt the whole problem. I would not start replacing ANYTHING. What you need to do is find a competent shop that actually knows what it is doing. Looks like this is a wiring harness problem. But the problem needs to be properly diagnosed. Find a good shop, and just drop the car off to them. Tell them you do not expect to get soaked for the work, but by the same token they can have the car as long as they need to find the problem (within reason). Give them a month if yo have to. They can use your car as back-fill for times when things are slow. On the plus side, if the problem is becoming more frequent, then it should by the same token be easier to find. If all else fails, then find a Five Star Dealer and drop it off to them. A friend of mine had a weird problem with his Firefly stalling on the highway at 80kmh! Just driving along fine, and sudden "flame-out". Three shops did not do the trick! So I told him to take it to GM. The catch??? If you schedule your repair far enough in advance, then tell the dealer that you need a loaner car! My friend needed the car to get to work. So called GM, and sure enough, he had to wait a month, but they gave hime a loaner car. GM was able to reproduce the problem - but it took them almost 4 weeks to fix! The final computer print-out was over 5 pages long of the work performed. They were so embarased that they only charged him for about 1/4 of the work done - about $800. That $800 bill was much less than it would have cost him to rent the loaner car for a month. He got the car back, and it was indeed fixed - not to mention largely rebuild! lol. So find a DC 5 Star dealer, and talk to the service manager. See if they can do the same kind of deal for you! Book in advance, get a loaner, and let them clunk away. Just make sure that you set a limit with the manager - say $800? and tell them that if the bill will be more than the agreed amount, that they MUST get your permission to proceed. A lot of service forms acutally have a section for this right on them. If you fill it out, it covers your butt. Good luck with it my man. I had a 1988 Olds Cutlass that had in intermittent flame-out. Never did get it fixed, just traded it in. Fortunately for me it did not flame-out while they were test-driving it! :)))))) The dealership is going to give a loaner for a month for $800.00 of labor? I don't think so! You see the problem is this guy has not taken it to the Dealership, so effectively he is not " a good customer" So why is the dealership going to bend over backwards and give a loaner for a month, and only charge him $800? My friend was not a longstanding customer of the GM dealer either. Dealers charge PREMIUM DOLLAR. Basically, it was their fault that they could not find the problem quickly. They were sure they would have had the guys car working in a day or two. But the agreement was to provide him a loaner car until his was fixed! My friend did NOT just walkin and say give me a car for a month. Techincally, it is not what he wanted. All he wanted was 1) wheels to get to work, and 2) his car fixed right. He did go to the dealership at my suggestion after seveal shops could not find the problem. And I hear this more and more from independant shops. I was having a problem with the ABS on my 94 Acclaim. And my #1 shop told me that there was ONE thing they would try to fix it, and if that did not work they were refering me to the dealer because the DC ABS system on the car was "a piece of crap". Be that as it may, the dealers are the experts (supposedly). 5 star dealers are supposed to get that rating for superior customer service. So, if you are willing to pay the dealer service rate, and give them the time required to properly service the car, then why would they not welcome you and attempt to accomodate your needs??? After all, if they fix the car quickly and correctly, would you not tend to become a return / repeat customer???? Dealers usually have a fleet of cars that are offered to customers as loaners. It is a pure marketing write-off for them! They claim the depreciation as a write-off, and sell the cars as "new" "used" vehicles with full warranty for less, but they are not losing money! The theory is that if you are getting your OLD car fixed (again) and they give you this nice NEW car, some people are going to say "WOW, I really like these new cars! Better gas mileage, nicer creature comforts, easy to drive! I am tired of getting that old clunker fixed, I'm going to trade it in on one of these!" Lo and behold, if the new car is good, it can actually sell itself. It is a salesmans dream! A satisified customer just walks in out of the blue and says "I want it, now!". Sale is signed, sealed, and car delivered with minimum work required. (ANother9one bites the dust! ;) Dealerships exist for two reasons: 1) to sell cars, and 2) to provide service. It seems logical to me that is the service is good, then I would tend to want to reward the good service with future business either as repeast service, or when looking at new cars. A GOOD dealership should not only know this, but should practice this. If a dealer does not, then it is time to find a new dealer. >The dealership is going to give a loaner for a month for $800.00 of labor? I >don't think so! You see the problem is this guy has not taken it to the [quoted text clipped - 5 lines] >http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups >----= East and West-Coast Server Farms - Total Privacy via Encryption =---- Obviously you know nothing about service loaner cars. They are not write-offs. And they do cost the dealership money. Do you know what the insurance rates are for Loaner cars? Garage policies are over $30 a day per car. And since they are a vehicle that is also for resale, it is not a Write off! Why do you think the loaners have miles on them? Main reason is because they are Used cars bought at Auction (ex-rental / ex-company cars) DC even recommendsdealers not use new cars, to begin with, and if it was a new car put into service the dealer would lose there shirt. And it is that reason that MOST dealers do not even give Demos to sales people anymore because they are money losers. And the fact is depending on the size of the dealership they can see over 100 Service customers a day. And the dealership will not have 100 loaner cars for them. So they have three maybe 5 max. And they will not give one to someone who comes in for the first time with a used car that was never purchased from them. They keep them available for there customers, and repeat customers. >Obviously you know nothing about service loaner cars. They are not >write-offs. I said they were a TAX write off, not a collission write off. > And they do cost the dealership money. All of which is written off by accountants as a "cost of doing business". > Do you know what the >insurance rates are for Loaner cars? Garage policies are over $30 a day per >car. And since they are a vehicle that is also for resale, it is not a Write >off! They write down the value of the car at an accellerate depreciation rate. Then, they sell the car off for much less than "new", but for higher than the depreciated value on the "books". So it IS still profitable for them to do this. > Why do you think the loaners have miles on them? Main reason is because >they are Used cars bought at Auction (ex-rental / ex-company cars) Not sure how it is now, but this never used to be the case. Loaner cars from DEALERSHIPS around here used to be cars that were at most 2 model years old. Now independant service garages... mostly had the most aweful beaters umaginable. > DC even >recommendsdealers not use new cars, to begin with, and if it was a new car >put into service the dealer would lose there shirt. And it is that reason >that MOST dealers do not even give Demos to sales people anymore because >they are money losers. You lose the value, but get a tax credit in return. Like I said, cost of doing business. > And the fact is depending on the size of the >dealership they can see over 100 Service customers a day. And the dealership >will not have 100 loaner cars for them. No sh.t Sherlock. (pardon the sarcasm) > So they have three maybe 5 max. And >they will not give one to someone who comes in for the first time with a >used car that was never purchased from them. They keep them available for >there customers, and repeat customers. Like I said, you have to book a loaner car in advance! This is because the dealer only has a limited number of service loaner cars. I think this dealer had 5 or maybe 10 MAXIMUM, and they did NOT advertise the fact either. Fact still remains, business is built - or lost - one customer at a time. Of course the longstanding customers are going to get "dibs" on loaner cars. But if the OP books far enough in advance, and discusses the matter with the Service Manager first, then there really should not be a problem! If there is, don't go to that dealer. Most dealres I have dealt with are at least approachable as long as you are not being demanding or an a.shole. You approach, and it is a business propsition. You are looking for service, and good quality work at a fair price. In return you are offering customer loyalty, and a lonstanding, mutually benficial, business relationship. Surely a competant service manager could see the advantage in gaining such a customer, yes??? Besides, at this point what has the OP got to loose??? The worst the dealership could say is "No", in which case they loose the business, and the OP is no further behind than before! To the OP, Go for it! No guts, no glory! Newman. It is not a tax writeoff. The dealer has to resell the vehicle. Legally he cannot write of the losses of a loaner then resale the car. That's fraud. He has to eat those losses. They can only write down the value of depreciation on vehicles not licensed, not on vehicles being used as loaners. Those have to be licensed to the dealership, and all losses on "of use" vehicles are the dealerships responsibility. So he buys a car with 12,000 km's at the auction for $15,000, licenses it, insures it and uses it as a dealership loaner, after one year, it has 30,000 km's and has a value of $10,000. Guess what, he lost $5,000 in depreciation, license and insurance fees. He cannot write it off as he is reselling it as a used car on his lot. So he just ate over $5000, per car! That is why some dealerships get tight giving out loaners especially slow periods like winter. They are not selling cars, not getting service work, and are loosing money. So they clamp up extra's. Did you know most dealerships actually lose money in January and February. I really love how you guys think dealerships are all rolling in the dough. Do you even know how much it costs the average dealership a day, just to turn on the lights? I used to work with DC and called on many dealers. Did you know that one dealer actually had a Honda Motorcycle shop, and made more money selling a Honda lawnmower, then on a car? Made more then double selling a $26,000 goldwing then two Fully loaded Gr. Cherokke limiteds? > Newman. It is not a tax writeoff. The dealer has to resell the vehicle. > Legally he cannot write of the losses of a loaner then resale the car. [quoted text clipped - 20 lines] > Honda lawnmower, then on a car? Made more then double selling a $26,000 > goldwing then two Fully loaded Gr. Cherokke limiteds? The other thing about this loaner car issue is that the idea that someone bringing in an "old clunker" to a dealership to get it fixed is going to come back from the loaner car and immediately buy a new car is a fantasy, it almost never happens. New car buyers typically aren't the kind of people that wring every last mile out of their car. A few of them are, but most are the folks that trade in their 2-4 year old car for a new one. They aren't driving old clunkers, if anything they are turning the car in the second the warranty runs out. The old clunker drivers are the folks on the bottom of the economic scale who cannot afford to depreciation loss of buying a new car. And they hardly ever go to a dealership, if the old clunker breaks down to the amount that an independent cannot fix it, then off it goes to the wrecker, there's plenty more old clunkers where it came from. The folks that could be enticed to go to a dealership for repairs who normally frequent independents are the folks that are first generation used car buyers, these are the folks that buy cars that the new car buyers have traded in. Thie cars still have a high enough blue book that the owners would seriously contemplate throwing $1500 in repair costs at a dealership into them. They aren't going to want to buy a new car for replacement, and they aren't going to be that interested in buying a used car because they know that any used car they buy will probably be in no better shape than the one that they have. The argument that NewMan is making is the sort of thing that sounds like someone who has no intention of buying a new car would be trying to use on a car dealership to con them out of a loaner car. It does not pass the sniff test. And also I am always suspicious of "tax write off" arguments anyway. In order for any business to take advantage of a "big tax write off" they have to have profit to write it off against. What the hell good is a $50,000 tax write off when the dealership has only declared a profit of $20K for the year? And before anyone starts in with the dealership owners are rolling in dough argument, let me point out that just about all dealership owners pay themselves a salary that gets pulled out BEFORE profit is declared. If I owned a dealership that would normally declare a profit of $1,000,000 for the year, I'd pay myself a salary of $990,000 and send most of it into a tax sheleter, and make for damn sure that the dealership only realized a very small profit. Thus any tax write offs would really be coming off my salary, since I'd have to reduce my salary to increase the dealership profit so they could then take the larger tax write off. Get it? Ted Ok called AutoZone, they said they would be happy to hook an ODB II up and read the codes for me. I went down there and the tranny went into limp 2 times on the way. When I got there he brought out their store Acctron ODB II scanner hooked it up, turned on the key and got link errors the 3 times he tried it. So he sent me off saying I need to find an electrician. They also balked initally when i told them it was a 95 saying it needed to be ODB II... Drove it back and it went into limp. Neurtal, killed engine, restart and it was fine the remainder of the way back. I am at a loss here. Could it be something else electrical like battery/alternator? Should I just replace the blasted TCM or is the engine computer also likely having issues since both times my car has been scanned for codes in my presense it had communication issues? > Ok called AutoZone, they said they would be happy to hook an ODB II up > and read the codes for me. I went down there and the tranny went into [quoted text clipped - 11 lines] > having issues since both times my car has been scanned for codes in my > presense it had communication issues? Hi Richard... Can you tolerate yet one more suggestion from an old retired electrical guy? If so, I think I have what may be a good one, but please don't try it unless and until you hear a blessing from one of the mechanics here. I'd hate to contribute to your problems... If so, here goes :) We know that limp mode forces the transmission to downshift to second. Can we also safely assume that limp mode will force an UPshift from first to second? If that's a safe bet, then how 'bout parking your machine about a half inch away from something immovable and un-damagable. Only a half inch or so, so nobody can possibly get between the car and the "thing" (bridge abutment?) Take off your tie, no long sleeves, put the 4 year old safely indoors. Chock the wheels firmly - even backwards, in case the foolish car decides reverse gear is a good idea. Parking brake on firmly. Start the motor, put it in drive, and with a long stick or handle end of a screwdriver poke, push, prod, and twist a bit each of the cables, connectors, sensors, etc. Do a little bit of percussion on each of the sensors. Do the same with the tcm. (Remember that if you get near to the knock sensors a reaction from the engine is expected and a good thing) If you don't get finished within 3 or 4 minutes, shut her down, let it cool, and start again from where you left off. Obviously what you're looking for is something that will cause it to shift... I'm sure you'll hear it if and when it does :) If and when you find something reliably repeatable, you'll be awful close to the solution methinks :) Now hopefully one or more of the mechs will either bless or condemn this idea. Take care. Ken >Hi Richard... > [quoted text clipped - 9 lines] >second. Can we also safely assume that limp mode will force >an UPshift from first to second? Yes. These transmissions are electronically shifted. The only "true" hydraulic gears are 2nd and Reverse. >If that's a safe bet, then how 'bout parking your machine about >a half inch away from something immovable and un-damagable. [quoted text clipped - 5 lines] >the foolish car decides reverse gear is a good idea. Parking >brake on firmly. If the parking brake is properly adjusted, it should hold the vehicle in place if it is at idle and in gear. There is also the option of putting the vehicle up on jackstands.... >Start the motor, put it in drive, and with a long stick or >handle end of a screwdriver poke, push, prod, and twist a [quoted text clipped - 20 lines] > >Ken Hope this helped..... Ya know, I just woner.... Electricity plays such a big part in things these days... My 94 Acclaim acted really weird once. I was scared to crap that the thing was going to need a major repair by the behviour. But when I took it to my local shop, they found an intermittent short in one of the battery cells! $100 and I was on my way, my problems never came back! Considering they could have soaked me something terrible... they now get almost all my business. Have you taken a close look at the battery? Over time crap drops off the plates - CONDUCTIVE CRAP. It builds up in the bottom of each cell. If the height of the crap reaches the bottom of the plates, then you get a short. If you are lucky, it just shorts and you can easily find the problem. If you are not lucky, it is an intermittent short! Such a short can wreak havoc with any and all electronics - including your ECM and TCM! Hey, keep it simple! This should be easy to check. But even if you just wanted to swap in another battery temporarily, that would tell the tale! Just a thought. Wouldn't it be a kicker if that was the problem after all your agony to date? Good luck. >Ok called AutoZone, they said they would be happy to hook an ODB II up >and read the codes for me. I went down there and the tranny went into [quoted text clipped - 11 lines] >having issues since both times my car has been scanned for codes in my >presense it had communication issues? > Ok called AutoZone, they said they would be happy to hook an ODB II up > and read the codes for me. Richard, This is a 1995 car which is an OBD-1 not an OBD-II car. Autozone was correct, (surprising) As the other poster said you cannot get trans codes from the key on-off method on this car. Please review picture # 78 on the following pictorial that I created last year: http://www.freebsd-corp-net-guide.com/94tcpics/project.html See that scanner there, that OTC 4000E? That's an OBD-1 scanner. Autozone does not sell these because when new they cost $2K and it's been 11 years since a production vehicle used OBD-1 Nor do they have them behind the counter. Now, on the above pictorial please review pic #57. See the sensors above that shiny box in the center? Those are the input and output speed sensors. Notice how the input speed sensor is right under the input and output lines for the tranny oil? That is a common leak point, what happens is the rubber tranny lines soften and start weeping fluid, the fluid wicks down to the input speed sensor and softens the rubber, thus making the connections in the sensor become intermittent. Get yourself some spray contact cleaner from an electronics store, unplug those connectors and spray down each side really good to drive all the oil out. Then use a small paperclip and insert it into each hole in the plug to make sure that each contact has enough "grab" left to make a good connection. Now, follow the wires from those sensors up to the trans computer. There are a couple places they pass very close to the exhaust manifold, make sure they haven't come in contact and got burnt. Now at the TCM take the big connector off and soak it and the plug down with your spray contact cleaner. When you first went to the dealer, they said the TPS, and the two sensors were bad. They got that info by using a Chrysler scanner that can read those codes. Have you done the analog voltmeter test on the TPS that I told you to do yet? > and it was fine the remainder of the way back. I am at a loss here. Why are you at a loss? People have told you it's probably an intermittent contact and to check the wiring harness and sensor connections, but at no point have you said that you did so. You said you replaced the input and output speed sensors and the problem didn't go away. Thus, the old sensors were most likely not bad. Yet - the dealership told you they got codes for failed sensors. So if the sensors wern't bad (as proved by the substitution) and the TCM is saying they are bad, then the problem is most likely between the TCM and the sensors, and that means all of the wiring and contacts. > Could it be something else electrical like battery/alternator? Should > I just replace the blasted TCM or is the engine computer also likely > having issues since both times my car has been scanned for codes in my > presense it had communication issues? The TCM talks on the CCD bus and the engine computer in your car does not, that is why there are 2 separate connectors for a scanner, one for the CCD bus to read the TCM (and other devices that plug into the CCD bus) and the other connector to talk to the engine computer. Richard, I have spent probably close to $400 on my used OTC scanner, plus about another $100 on a literal pile of factory service manuals for my vehicles. With the labor I've put into my vehicles, those tools have paid for themselves many times over, if I had paid a mechanic to do the amount of work I've done. Being able to do your own work diagnosing computerized vehicles means you have to get the right tools to do it, it means you have to do some reading and learning. You so far aren't doing any of this, you are just trying to get a lot of people to make guesses for you. When people have suggested to you things to do that appear to be difficult - like researching, getting a manual, checking wiring, and so on, you ignore those suggestions. When people have suggested easy-to-do things like replacing the TCM, replacing the alternator or battery, you have jumped at those ideas. It is no wonder your having problems, your whole approach to troubleshooting is massively f.cked in the head. Ted >Why are you at a loss? People have told you it's probably an intermittent >contact and to check the wiring harness and sensor connections, but at [quoted text clipped - 5 lines] >most likely between the TCM and the sensors, and that means all of the >wiring and contacts. Ted I have checked the contacts, and did so again last night. The tranny shop allegedly did as well, I went as far last night as removing the computer and burnishing the contact pins with a scotchbrite pad. >> Could it be something else electrical like battery/alternator? Should >> I just replace the blasted TCM or is the engine computer also likely [quoted text clipped - 28 lines] > >Ted I'm doing my best within my means however the best option for a quick diagnosis may be purchasing a $4k scanner and trying to see the problem happen however I cant do that. Maybe the following will make you understand. Hi Ted, my name is Richard. Just an average Joe trying to make ends meet. I and my family live paycheck to paycheck so when something catastrophic like this happens its devestating. Thus why I havent just dropped it at a dealer and said 'fix it'. I cant afford that, I had to get a loan to pay for the botched rebuild. Now my cash reserves are at a minimum, every decision I make here counts. So far my car problems have stranded my wife and kid at home for nearly two weeks and through that cost my daughter the ability to get signed up for the dance clases she wanted. So again I say I am taking every possible suggestion that I can afford. However so far I have had dodge dealer pull what to me nearly amounts to bait and switch, a tranny shop pull some bullshit outta their hat that they 'only fix transmission not the controls' despite their assurance that if the rebuild didnt fix the issue they would find it. As for the cheap suggestions like TCM, Alternator, Battery the reason I jumped on those is its very obviously either one of those or wiring. Last night I tested the charging system on the way home. While idling along at 35mph I Turned on every eletrical accessory in the car. I also loaded the systm by running all 4 power windows are the same moment, holding their switches in the close position while they were fully closed. Nothing happened so to me this really leaves alternator and battery out. So i am left with wiring and computer. If there is something I am missing someone may correct me or they may not. My approach to troublshooting is fairly logical, Ive done a lot of my own automotive work over the past 20 years(the first serious piece of work I did was rebuild an a904 tranny on my Dart that my dad gave me so i could drive it), however I am in a position now where I dont have the tools or equipment I used to have access to so its much harder to accomplish tasks. I'm sorry if my spit and bailingwire approach is pissing you off but I am doing the best I can with the little time and money I have. > >Why are you at a loss? People have told you it's probably an intermittent > >contact and to check the wiring harness and sensor connections, but at [quoted text clipped - 10 lines] > removing the computer and burnishing the contact pins with a > scotchbrite pad. Ok, well then let's look at it this way, we have to start making some assumptions here. The best would be to get it scanned again and see if the bad sensor codes are still present. But, failing that, let's make some logical deductions. We start with a trans that's throwing itself into limp mode intermittently, and dealership scan results that said the input and output speed sensors are bad. I'll ignore the TPS for a moment, because as I mentioned already you can independently test for that with an analog ohmmeter. (and you should do this, to either eliminate it or to put the blame on it) Occam's razor dictates that the most likely problem is in fact bad speed sensors. So the first thing we do (after eliminating the TPS) is replace the sensors. But the problem does not go away. Now, the set of possibilities are: 1) internal trans problem that causes the input and output shaft speeds to actually change speed to the illogical speeds that triggers the TCM to set a code. This is the least likely scenario since if it was the case this would be very repeatable, in fact it would probably be permanently in limp mode, or at least go into it much more commonly. 2) Interference of the sensors from an outside agent - ie: A/C clutch or surge - easily checked by disconnecting all known outside agents. 3) New sensors are bad. 4) Wiring from TCM to the sensors is bad 5) TCM itself is bad. Now, so far you have eliminated #1 (since you had the trans rebuilt) #2 (since you disconnected the A/C) #4 (since you checked the wiring and connections) What is left is #3 and #5. (or possibly both) A professional mechanic who had replaced #3 would test for #3 by simply extracting both -new- sensors, and sending them back to his supplier and claim both are bad. The supplier would replace them with new ones, and the mechanic would install both new ones, send you on your way. If you came back a second time, the professional mechanic would then be 99.9% sure that the sensors were not the problem. You could try this - assuming your new sensors are still under warranty. I deplore this kind of thing though since it's shotgunning of the worst kind, I am only saying this because I know it goes on a lot in the business. If that didn't work (most likely it would NOT work) the professional would would probably then move to recommending replacement of the TCM itself. If that didn't work then if the professional mechanic was -very- well versed on auto electrical, he would start checking power supplied to the TCM itself, wiring, and so on. Of course, if he was doing his job he should do this before recommending TCM replacement but that is another story. > >> Could it be something else electrical like battery/alternator? Should > >> I just replace the blasted TCM or is the engine computer also likely [quoted text clipped - 32 lines] > diagnosis may be purchasing a $4k scanner and trying to see the > problem happen however I cant do that. This is why you pay someone with that $4K scanner to do the diagnosis. Where you got screwed over was that you didn't know before you got into this that it would in fact require a $4K scanner to do diagnosis. That is why I told you that it would, so that at least you would know. > Maybe the following will make > you understand. [quoted text clipped - 4 lines] > dropped it at a dealer and said 'fix it'. I cant afford that, I had to > get a loan to pay for the botched rebuild. What about charging back the failed rebuild as some folks recommended already? After all the trans shop was paid to fix your trans, they didn't do it, and you gave them a chance to honor their warranty and they have decided not to do it. Why then do they deserve to get paid? > Now my cash reserves are at > a minimum, every decision I make here counts. So far my car problems [quoted text clipped - 28 lines] > I'm sorry if my spit and bailingwire approach is pissing you off but I > am doing the best I can with the little time and money I have. It isn't pissing me off, not really. It's frustrating me that people come to this group after they have got themselves stuck in a hole and then ask for advice, rather than asking for advice before doing anything. In a way I guess I do take it a bit personally, since I've spent a lot of time documenting my own trans issues so that people can learn, and I've also contributed to the Allpar website as have other people. Yet people aren't reading those sites or Googling them before running out and doing things. It is also frustrating when people come to this group with NO factory service manual, or with a Chiltons manual, and ignore the advice from the group to either get a FSM or get a subscription to Alldata DIY for their vehicle. Not that you are in this group of people, I don't recall that anyone has told you to get a FSM. Anyway, good luck with it, I think I've laid out for you how I would go about fixing it. You are not in a good situation because until you get that chargeback upheld by the credit card company, you are going to have to hold on to a vehicle that isn't reliable enough to use as a daily driver. You no longer have the option to just sell it and cross your fingers and hope that the thing does not go into limp mode while demonstrating it to a buyer. The only advice I can really add to the above is the following: this is a mechanical system, it has no intelligence, and something is causing it to behave this way. In other words, there is definitely a fault somewhere, and if you or someone else works with it for a long enough time, checking and rechecking, your going to find it. Just keep that in mind and don't give up. Ted Richard - read my original reply. Your symptoms are identical to mine : goes into limp; shut it down; start it up and it's fine; might stay fine for a few minutes or even a day; then it comes back, etc etc. In my case the problem was fixed by replacing a wiring harness. The dealer went through thousands of dollars of mechanical parts with no effect before they finally nailed it as an electrical problem. This was all 7 or 8 years ago so I no longer have the details about which harness. The work was done at this dealer : http://www.taylor.fivestardealers.ca/ Perhaps your dealer can get in touch with them for advice. The Technical Dept for Chrysler Canada got involved with this one because it was a warranty job and the car was Leased by G.E. Capital - and G.E. carries a big stick. Phil > Hello, > [quoted text clipped - 71 lines] > > Help! If it was a warranty problem Chrysler got involved because of the cost of the dealer replacing all the parts without a solution. As a matter of Fact DC more then likely ended up getting charged back every penny they spent replacing parts on the car, that did not fix the problem. GE does not wield a big stick with Chrysler. DC Canada actually does not look highly with GE as Ge Fleet services does not properly insure that there fleet vehicles are maintained, and DC refuses to take back any GE fleet vehicle back because of it. Ok so today here is what I have. Went for a drive to get gas, went into limp very soon after that. So I took it over to Advance Auto parts to see if their code scanner could have any better luck. It was able to read it. Here is what it dumped. ENG: 24/P0123 TPS Voltage High ENG: 33/----- A/C Clutch Relay CKT Not much help there, the 33 code according to the code list I have says it could also be the following; A/C pressure sensor volts too high A/C pressure sensor volts too lo Speed control switch always low Speed control switch always high Speed control solenoid circuits High speed condenser fan control relay circuit High fan and high fan ground control relay circuit So nothing for the transmission or why it went into limp because according to the tranny manual the TPS cant force the tranny into limp. I did notice today that the tranny is exhibiting two other odd symptoms. Sometimes when at a stop, it takes time for it to go into 1st gear and shift rather hard. Other times when coming to a stop it will downshift roughly at 28mph as I am stopping. I checked with Dodge today to see if they can provide a replacement wiring harness for the TCM and sensors, they said they show a 'Trans Wiring' item on the books and that its just about $280 and has to be special ordered. So if I were to get the trans wiring, for $280 and the computer from Dodge $250 and have them set the pinion angle and update the flash $90/hour labor 1 hour minimum. Do yall think this should settle things up? Oh yeah add in TPS for $80. >Ok so today here is what I have. > [quoted text clipped - 27 lines] >1st gear and shift rather hard. Other times when coming to a stop it >will downshift roughly at 28mph as I am stopping. Uh huh... Let me guess, the shop the rebuilt the trans used Dexron III trans fluid? My A604 used to downshift exactly as you described after being rebuilt. It was not until I had the fluid and filter replaced a couple of years later that the problem went away. I discovered that most trans shops used Dexron III with an additional addtion of "LubeGuard". The shop that dis the fuild & filter change used ATF+4! Double check with the shop that rebuilt your trans several times. My bet is that they used the wrong fluid to save money (their money) and which if left in your trans will lead to premature failure and repeat business for them! >I checked with Dodge today to see if they can provide a replacement >wiring harness for the TCM and sensors, they said they show a 'Trans [quoted text clipped - 5 lines] >$90/hour labor 1 hour minimum. Do yall think this should settle things >up? Oh yeah add in TPS for $80. You know something, this is STILL a "shotgun" approach! No matter how logical your approach, you do NOT know if ANY of the above will solve your problem without a definitave diagnosis! From where I sit, you simply cannot aford NOT to go and get the problem diagnosed! Until you have a diagnosis, you could just keep pouring money into the thing! I am sure you realize at this point that your transmission may have been just fine to begin with! How much was that? $1800???? I think that the dealer could spend 2 hours on this, so $180, and then tell you what the F&ck is wrong. THEN, rather than replace a whole bunch of parts and pray you got "the one", you could spend exactly what you HAVE to spend and get the car fixed properly. By avoiding spending money for a proper diagnosis, you are being penny wise, and pound foolish. Hey it is your dime, but YOU are the one who said you were trying to save money. I don't see how spending $1800, plus how much for a tow, and then throwing another - what - $700 at this problem with NO IDEA of whether or not this will fix the problem is "saving money". How are you going to feel if you spend the extra $700 (plus tax), and the problem persists???? How much is this car worth anyways??? Just my $0.02 >Uh huh... Let me guess, the shop the rebuilt the trans used Dexron III >trans fluid? You are probably right, it wouldnt suprise me in the least hell I dont even think thats my tranny in the car anymore. The one that was in there when I took it to the shop had writing on top in that yellow paint pen wrecking yards use and had a dar dirty bellhousing. This one is shiny and clean. No I dont think they cleaned mine because at the place where the writing was is a factory sticker of some sort that looks like its been on there for years. In addition when they replaced the #$@$@ solenoid pack they didnt put the sount suppressor back over it so not the solenoids are much louder. Maybe I will have the DC Shop just flush the fluid just in case the old tranny shop lies... >>I checked with Dodge today to see if they can provide a replacement >>wiring harness for the TCM and sensors, they said they show a 'Trans [quoted text clipped - 13 lines] >problem diagnosed! Until you have a diagnosis, you could just keep >pouring money into the thing! Here is my problem, I took it to Dodge once, and they offierd to 'fix' my problem by replacing the two speed sensors and the TPS for $510. I replaced the speed sensors and it had no effect. I am now dealing with a different dealership though. What I want isnt too much to ask, I want to walk in and drop off my car. Have them fix the damn limp mode issue and have it BE FIXED. The problem is its so damn incosistiently going into limp mode that no dealership is going to agree to this. They can change out 100 things and it may still go into limp a week later. Since none of the local dealerships is giving loaners I cant afford to have my car in the shop every other week while they figure out wth is wrong. Thats why I am moving to the shotgun approach. Yes its stupid to buy an engine when the only thing that needs to be changed is a leaky valve cover gasket, however, when you cant find the bloody leak and dont have the luxury of spare vehicles to drive while someone figures out your problem you may just have to go BAM. >I am sure you realize at this point that your transmission may have >been just fine to begin with! How much was that? $1800???? Initally my transmission was fine, when I took it to Dodge. I replaced the sensors took it to work and it dropped into limp on the freeway. That evening when I went to leave work there was no 2nd gear left. & |
Enable EMail Alerts
Start New Thread
Reply to this Message