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The traction control light on dash won't go out ever since I changed the ECM out. It doesn't appear to be the switch in the center console. Could my changing the ECM(used) have anything to do w/it? Thanks for any help. Larry
 

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I'm posting on behalf of my dad to perhaps clear things up, provide a background to the problem, as well as give an update to the status of our troubleshooting efforts.

The last time the car was driven when the problem wasn't observed was the [short] trip I made when the engine died (click to view thread) due to a short in some wires near the EGR sensor at the rear of the engine compartment. In the troubleshooting of that problem, my dad bought and installed a used PCM from a local boneyard, after which the light has always been on. I've suggested replacing the used PCM with the original PCM but he would rather not until he's sure that the problem isn't elsewhere.

Yesterday evening while I was fixing the speedometer accuracy problem I took out the center console and disconnected the traction control switch. I started the car and observed that the T/A OFF light remained active. I then took a paper clip and shorted out the switch to simulate the button being depressed, to which no response by the car indicated on the instrument cluster was observed.

My next step in checking the switch would be to take a multimeter and check for a current through the switch. If there isn't a current, would that indicate a faulty PCM, a PCM that perhaps came from a vehicle that didn't support traction assist, or perhaps a loose connection at the PCM?

If there is a current, would that indicate a faulty PCM? Either way, I think I'm going to be forced to replace the "new" PCM with the "old" PCM.

Finally, if/when we do end up replacing the PCM and the problem persists... are there any other things that we should examine that might be causing the problem? If it means anything, I know that the car does not have ABS.
 

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Per the EVTM, the Traction Assist light is controlled by the "Anti-Lock Brake Control Module".

The "Taction Assist Switch" provides switched 12v power to the contol module when the switch is closed (on). (Pin 25 on the module)

The "Anti-Lock Brake Control Module" appears to provide a ground for "Traction Assist Indicator" in the instrument cluster. (Pin 44 on the module)

So if the light is staying on, either a wire (black/light blue) between the indicator and the control module is grounded; pin 25 is seeing 12v; or the module is bad.

I can't find anything in the EVTM that showes traction assist without the anti-lock control module.

Hope that helped some.
 

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So what I understand is that the PCM and the ABS control module are two separate units.

Logically, based on my own fuzzy thinking patterns, if the T/A OFF light was never on (the switch did work before, as I recall), that would mean there is an ABS control module in my car, which does not have ABS.

Any ideas to where the ABS control module might be? If it's a separate unit from the PCM, I'm thinking perhaps a wire was pulled loose when my dad took out the old PCM.
 

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I finally got around to changing the PCM back to the one that originally came with the car. No difference; "T/A OFF" light stays on...

I should be getting my shop manuals in the mail shortly to help me diagnose the trouble, but I still can't understand how my car could have traction assist without ABS. The T/A off light was never on before...

EDIT: Traced the problem to the ABS System, which the car does indeed have. I'll work at it from there.
 
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