PCM ?

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L.G.R. - 29 Nov 2007 22:11 GMT

Hi all.
Why is it that the PCM does not communicate with the transmission nor the
ABS and also not with an other one wich I dont remember. Aparently that's
the cause why the cluster is not fonctioning, as I have tried an other one
and nothing doing.
I am just comming out of a garage where I have been 3 hours doing all the
possibles tests and searching, and they coul'nd fix it. So they sais that it
is the PCM that is défect. But it has been changed 4 months ago at a
Chrysler dealer.
Any suggestions? Thanks

L.G.R.

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Bill Putney - 30 Nov 2007 00:42 GMT

> Hi all.
> Why is it that the PCM does not communicate with the transmission nor the
[quoted text clipped - 8 lines]
>
> L.G.R.

Which vehicle/year? Is this a pci bus problem (that's the single-wire
bus over which all the modules communicate with each other)? The other
module is probably the BCM. Air bag module too. ATC module too if it
has that. The pci bus is generated by the BCM. Any one of the other
modules could develop a fault that could drag down that bus (or the BCM
itself could have the bus-killing fault), and without some good
troubleshooting techniques, it would be hard to know which module was
the culprit.

Does the cluster show "no bus" in the odometer window? I'm out on a
limb here not really knowing which vehicle, but making some guesses.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

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L.G.R. - 30 Nov 2007 12:48 GMT

>> Hi all.
>> Why is it that the PCM does not communicate with the transmission nor the
[quoted text clipped - 10 lines]
>
> Which vehicle/year?

Thank you for answering.
The car is a 98 Voyager Expresso

Is this a pci bus problem (that's the single-wire

> bus over which all the modules communicate with each other)? The other
> module is probably the BCM.

The BCM also have been changed for a new one 4 months ago along with the
PCM. Cost me 1700$ for both (wich I regret). But aparently you cannot change
the PCM without changing the BCM also as they have to be programed both for
the car.

Air bag module too.

In the steering? Have been repared at the same time under company recall.
(The famous spring for the horn, the air bag and the cruise.)

ATC module too if it

> has that. The pci bus is generated by the BCM. Any one of the other
> modules could develop a fault that could drag down that bus (or the BCM
[quoted text clipped - 4 lines]
> Does the cluster show "no bus" in the odometer window? I'm out on a limb
> here not really knowing which vehicle, but making some guesses.

That is still fresh in my memory what the mechanic told me but it is like
chinese for me.
Have a good day.
L.G.R.

> Bill Putney
> (To reply by e-mail, replace the last letter of the alphabet in my address
> with the letter 'x')

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philthy - 01 Dec 2007 21:10 GMT

just because you replace a pcm does not mean you also need to replace the bcm
what a line of crap the dealer fed you esp. if the parts are new now if it was
a used pcm set up for skim and your ride did not have skim then the bcm would be
junk
the bus system you have is a 2 wire bus

> .
>
[quoted text clipped - 48 lines]
> > (To reply by e-mail, replace the last letter of the alphabet in my address
> > with the letter 'x')

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maxpower - 30 Nov 2007 20:14 GMT

> Hi all.
> Why is it that the PCM does not communicate with the transmission nor the
[quoted text clipped - 8 lines]
>
> L.G.R.

Now that we know year make and model, check the connectors directly under
the battery tray to see if they are all corroded. That is a common problem
if the battery has been leaking acid.

Glenn Beasley
Chrysler Tech

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