2007 Tahoe Stabilitrak Question

[cbruhn]

I have a 2007 Tahoe LT that has two issues going on. One is a mis-fire on cylinder 7 that the reader at Autozone picked up.

The other issue is the stabilitrak light randomly comes on, typically while I'm stopped or in first gear. The code reader couldn't pick up anything on this other than there is an error.

What's happening is if the light is on the truck will shift hard to second gear and then when it shifts to 3rd gear the light clears.

If the light is not on shifting from 1st to second is smooth.

This feels like a sensor issue with it being so random, but wanted to see if anyone else has experienced this and has a good place for me to start looking. Am I going to have to go buy a reader at AutoZone for $90 to get transmission codes?

 

[Fless]

A misfire can cause the stabilitrak issue. Focus on the misfire.

 

[cbruhn]

Out of curiosity and ignorance, how does a misfire case the stabilitrak issue? I'm a rookie at this.

 

[Marky Dissod]

Out of curiosity and ignorance, how does a misfire case the stabilitrak issue?

One of several things the pcm does - or ecm & tcm do - during a Traction or Stability Control intervention is spark timing retard.
However, if a cylinder is misfiring the instructed amount of spark timing retard will take away too much power.
So if any misfire codes are set, Traction & Stability Control are either severely limited (brake calipers may or may not still intervene) or made entirely unavailable.

 

[kbuskill]

Out of curiosity and ignorance, how does a misfire case the stabilitrak issue? I'm a rookie at this.

Basically if you have something causing a misfire the ECM will disable Traction Control and Stabilitrac (just as if you held down the T/C button to disable it manually) by default to see if that system is causing the misfire. It is just the way GM programmed the ECM, kind of like a "limp mode".

 

[cbruhn]

UPDATE: Replaced all my spark plugs, coils and wires and everything is resolved... so far. It's been almost a week and no more misfires and no stabilitrack light. Thanks for the help!