greg8453

This would be in the service lit correct? Where do you find it?

donbrew

It takes some thought.
If you look at the specs for conditions to run OBD2 tests you will find almost all require closed loop. If an engine performance related test is incomplete or failed the traction control will be turned off, because there is no need for TC if the engine is malfunctioning (it should be parked).

greg8453

We are not talking about the engine management system running it's tests which some require both cold start and closed loop to run the test. Doesn't make sense to me. If you look at the service lit it doesn't mention closed loop as being a reason to turn on the light.

donbrew

Well, then go on being disillusioned. But stop insisting that engine codes have no bearing on TC.
Why else would a VVT malfunction cause the TC light? No mention in the literature of that being a result, but it does cause open loop.

greg8453

I know engineers do not make things very logical and those that write the manuals are far from perfect. I just never seen where repairing any engine problem cured a T/C light.

donbrew

Read this forum for the last 12 years.

firemangeorge

Yes...it can.
I've been on this forum a long time like Don. Seen many times where members fixing an engine problem will "reset" or turn off that TC light. Lots of different CEL's can trigger the TC to turn off. (light ON)
Which CEL's ? Who knows. That's one of those things the GM programmers like to keep to themselves.

Lonwane

These little gems are so computer interconnected that I'm suprised that changing the radio station doesn't initiate a CEL.

donbrew

Some of the lights and warnings are just to get the drivers attention. You would be amazed at the number of people that don't know what the "pretty red light" is for. So, they set off another light and a text warning on the dash. If it was a 757 the next step would be a puff of air in your face.

Lonwane

If the "pretty red light" was that important it would be flashing