The blinking 4WD lights is a signal from the computer (the "GEM") that runs
the Control Trac 4WD system that things are not well. Basically, the system
monitors the speeds of the rear and front driveshafts to see if the rear
wheels are going faster than the front. If they are, it means they are
slipping and the system will increase the power going to the front wheels.
It does this in steps until the front and rear driveshafts are essentially
locked together. At that point, if the rear still seems to be going faster,
the system figures this just cannot be and shuts off, flashing the lights to
indicate the problem. The way the speeds are monitored are with speed
sensors in the transfer case that splits the power from the engine between
the front and the rear wheels. Usually, this problem is one of the sensors
has failed, or the electrical contacts are dirty, or the "tone wheel" that
the sensor monitors is crudded up with gunk. It is not terribly expensive to
replace any of these sensors, and this can be done without having to remove
the transfer case or transmission or anything like that. There are other
things that it could be, and that are more expensive to repair, but they are
more rare failures. Some less-than-honest repair shops will try to replace
the whole transfer case, or the computer, but that is not normally needed.
The blinking lights shouldn't, by the way, cause you any problem except you
don't have 4WD.
=Vic=
Bear Gap, PA
> Hi everyone I am writing to see if anyone know anything about blinking 4x4
> lights on dash, my truck is always in auto and today it started to blink
[quoted text clipped - 6 lines]
>
> PLEASE HELP!!!!
soccermomct - 17 Mar 2006 14:40 GMT
Vic,
Thank you so much for your reply back to me, finally I have found someone who
is not out to take my money. Now when I take it to the dealership at least I
can tell them what I would like to try first instead of them selling me on
the most expensive fix that it may not even need. I will keep you posted on
what they say and do, again thank you so much this mom appreciates it more
than you will ever know.
thank you
soccermomct
>The blinking 4WD lights is a signal from the computer (the "GEM") that runs
>the Control Trac 4WD system that things are not well. Basically, the system
[quoted text clipped - 26 lines]
>>
>> PLEASE HELP!!!!
Searcher - 17 Mar 2006 18:12 GMT
The problem is most likely a sensor located in the transfer case. Cost of
the sensor is 17.00. Thats what happen to mine last year, it was an easy fix
that took less then 15 min. The hardest part is crawling under the vehicle
if you do not have a lift as I did.
Searcher
soccermomct - 17 Mar 2006 21:32 GMT
>The problem is most likely a sensor located in the transfer case. Cost of
>the sensor is 17.00. Thats what happen to mine last year, it was an easy fix
>that took less then 15 min. The hardest part is crawling under the vehicle
>if you do not have a lift as I did.
>
>Searcher
thank you so much you guys are the best and put my mind at ease, I feel like
a woman who is informed . Is changing the sensor that hard for me to do?
soccermomct
Searcher - 18 Mar 2006 00:45 GMT
No, you really shouldn't have a problem doing it yourself. If you are at all
mechanically inclined. I believe it is one bolt holding it in there and an
electrical plug.
Searcher
Tom Amundsen - 18 Mar 2006 22:14 GMT
Hello, Searcher!
You wrote on Fri, 17 Mar 2006 23:45:49 GMT:
S> No, you really shouldn't have a problem doing it yourself. If you
S> are at all mechanically inclined. I believe it is one bolt holding
S> it in there and an electrical plug.
S> Searcher
Not hard to do yourself, but, you need to know where they are. A manual
should be available at your local library. My advice is to clean the
metallic sludge off of them and reinstall, unless a wire is broken they
can't really go bad. The sludge that is on them is small metal bits
that have worn off of the gears over the years (they are magnetic
sensors). If you want to do this once, instead of every few months,
drain and replace the fluid in the transfer case. This will clean out
the sludge in the fluid, I think there is an impoved fluid compared to
the one that was original. Check the dealer on this though. The new
fluid can be put in with a turkey baster, its messy but the clutch packs
in the transfer case will thank you for it.
With best regards, Tom Amundsen. E-mail: tamund@comcastAWAY.net
wrote:
> Hi everyone I am writing to see if anyone know anything about blinking 4x4
> lights on dash, my truck is always in auto and today it started to blink when
[quoted text clipped - 5 lines]
>
> PLEASE HELP!!!!
Ask around and find an independent honest, competent shop. I'm sure
there are some honest competent dealerships but in my experience it's
the small mom and pop shops that will more likely repair what needs
repair and not what doesn't. I found a great shop I've been happy with
for years. Where are you located? Ask friends, relatives, gas station
employees, etc.