03 Envoy XL dash lighs

[weiss_david]

Does anyone know how to resolve the problem with service 4wd, abs, and brake lights staying on permanently at startup? This is an intermittent problem which probably only happens about 10% of the time. I have heard that replacing the ignition solves this, but others say this doesn't work. The dealer has checked the grounding, replaced the TCCM, and said the ignition seems fine.

[GMCTech]

The ignition switch is most likely the culprit.

I've replaced dozens with the exact same concern.

The only way to really test it is to have your mechanic test EVERY fuse at both fuse boxes. There should be about 1/2 dozen that will light some test lights, but only have 6-8 volts supplied to them.

Don't test them with a test light, use a multimeter. (Been bitten in the a$$ too many times using just a test light.)
Hope this helps.

[weiss_david]

Thanks! I was actually able to recreate the problem for my mechanic today by having the radio and fans on at startup. This reproduced the problem and gave him the codes to convince him that the ignition should be replaced (which I said on the first day that I brought it in). He had opened a case with GM and was not authorized to make a repair until the problem could be recreated. I made 3 visits and to the dealer and was on the 4th day of the 3rd visit when I decided to go over and show him how to make it happen. I had been told that there wasn't any safety issue, but meanwhile the ABS wasn't even registering. I wish GM would choose to recognize this type of problem and provide better information to their network.