My wife was driving my car and she said it came on, the car revved real high and shook. I just got home and it started up fine and was idling fine, but I have not drove it yet. It's a 2001 ZX3.
I had this happen to me about 2 months ago. My battery was shot, which would put me into the 'Charging system' category.The " ! " is a MAJOR warning light that something is not operating in the safe zone , something the ECU has no control over , a lot of times this is when the ECU goes into fail safe mode
Water temp to high
Oil temp to high
Low Oil Psi
Charging system
This will NOT show up as a ECL code and once the issue goes away (engine cools down) this light will go off by it self
For that light to come on it had to be something major
Tom
It is a multifunction light for the automatic trans/cooling system.