Hello, I drive a 2005 Chevrolet Monte Carlo LT with the 3800 naturally aspirated V6

Around Thanksgiving California got a lot of rain. It was at this time the service Traction System light showed up on the message center.

As it showed up my gauges would reset without warning, at the same time my brake pedal would modulate strangely. This went on for about 3 days

I plugged in my code reader and (no surprise) no codes were in the ECU


The problem only got worse within the last couple of days now when I start the car my entire dashboard lights up like a Christmas tree

and the OnStar light on my rearview mirror will shine red

on top of that I’ll lose the ability to use my turn signals (although oddly enough I can still use my hazards) and traction control button

Another thing that happens is that I’ll be driving with my dash board lit up and all of a sudden it’ll reset to normal

When this happens my OnStar light will return to being green

and I regain use of my traction control button and turn signals

also, my car will sometimes not start. And my car will sometimes start then stall, then start up fine after I turn the key again

Is this the sign of a bad ground or something else?

 

I also have the same issue with my 3800. 40,000 miles. Sometimes when I'm driving I'll have the service traction and abs lights turn on for a few seconds and then shut off. If you figure it out let us know.

 

BCM is losing communication with ecm and cluster.


Mine has intermittent issue like this. Haven't found fix yet. Thinking it's in BCM harrness.

 

Service traction system is a common issue with these cars and there are probably dozens of posts here about what to check. The solutions run from a broken wire to replacement of the ABS module.
The cheap easy ones are:
1. Check the ground on the front of the core support above the driver headlight. There is also a ground beneath the air filter box.
2. Check the front harnesses from the frame to the speed sensor plug for a broken wire or bad/loose plug. (which would cause a short when wet). GM produced replacement harnesses maybe 10+ years ago. A very simple temporary fix is to unplug the harness and plug it back in - this worked for me until the driver side harness wire completely broke from flexing.
3. Take some electrical tape and tape the speed sensor plug firmly to its bracket - the clip wears out and turning the wheels tugs on the speed sensor wires. Make sure the wires have slack.
Beyond these, the speed sensor is part of the bearing assembly.
Do a search - I know at least one post tells how to use an advanced reader to find the bad wheel.

 

Did you solve this problem?

I recently started having the Service Traction System/ABS/Traction Control lights issue only when I turned right. If I turned it off and restarted and only turned left, I was fine. I replaced the harness wires from near the cradle to the plug at both of the front wheels and have not had the issue since. I also zip-tied the ABS speed sensor plugs to the bracket as the plastic tent clips were very loose. They don't move now and so don't pull on the sensor harness either.