GM Repair Questions? Ask a Mechanic for Answers ASAP
Hello, I'm Cam. Please include all the details about your issue so I can accurately advise you. I cannot see your vehicle so please be detailed.
These years of trucks with the electric throttle have a couple of very common issues. First and in my experience most common is the ground wire. THe ground runs from the rear harness behind the top of the engine to the rear of the left cylinder head. It is attached at the same bolt as the ground strap at the firewall. I have always been able to find this by pulling on the black wire and see if it gives. The fault has been a conductor broken in the insulation at the crimp. The second issue is the wiring near the throttle body. The wiring tends to break a few inches from the connector. check these out and see. Another common issue is the wiring near the throttle body itself. There are some wires there that can break inside the insulation and cause this. Check the wiring carefully near the throttle and about 6" back.
2 weeks ago i got the message "reduced engine power" and so i turned off hte car and called the dealer, took in it and after their diagnosis they replaced the throttle body. after their repair, the vehile operated fine and I subsequently drove the vehicle from ca. to utah and back with no problems (1000 miles). i have been back to normal driving for the past few days and the message appeared again today. so, i'm not sure what to do at this point or what to ask the dealer to fix? based on your assessment, if there are wires/cables that can contribute to this problem, would that have been something the dealer should have analyzed, looked at and/or fixed when they replaced the throttle body? or are those cables/wiring a separate issue from the throttle body? should the throttle body have been replaced at all? so are you saying a short or a bad throttle body are the only causes for this problem? and if so, should a "short" have been explored when the dealer replaced the throttle body?
Yes, the dealer tech should have looked at the wires. They are much more common on these than the throttle body itself.
These issues with the wiring are directly related to the throttle as they plug into or are control wires for it
There is one more on micro corrosion called fretting for the app pedal sensor in the dash
thanks. appreciate your help!