2006 GMC Envoy Q&A
2006 GMC Envoy Question: On board computer
Battery was dead in my Envoy Denali so a friend boosted it but connected the cables to the main electrical box cables instead of the battery. Now I have no electrical power at all. Is there anyway to reset the computer or electrics. Check the fuses and they don't seem to be blown. - mehome
You may have over loaded/damaged electrical system components in your truck and scrambled some of the software in your engine computer or more. I would not jump start anything, there are too many computer systems in cars and trucks these days that can be damaged - dandd
Try completely disconnecting the battery for 5 minutes. Then reconnect it. These cars have a PCM (power control module) that stores all data, including idling data). When a battery goes dead, it zaps all or most of the stored data). It is possible that you have a partial store of past data. After a battery goes dead or you replace a battery in these cars, the PCM has to relearn its operating environment. After disconnecting the battery for 5 minutes or so, start the car and have it idle for a couple of minutes. Then idle the engine at about 1200 RPM for a couple of minutes. Take the car out for a spin in normal traffic in your normal manner. The PCM should relearn your driving habits in approximately 15 minutes or so. Just be prepared for surging and possible engine dying at stop signs/lights for the first 5 minutes of your initial driving outing after reconnecting the battery again. My son's 2004 Envoy took about a 20 minute drive after a battery replacement in order to return to its normal (flawless) behavior. Best of luck... - Visitor
I took it to 2 GMC dealerships and they stated no codes came on the computer.
Twice, I drove more then 200 miles at one time, my service engine, and the reduce engine power light comes on. I have taken it to the GMC repair shop several times and they can't find a "code". I ...