2008 1/2 Ton Suburban - 5.3L 2wd - Electronic Issues

Just bought a new suburban and atabout 300 miles it started acting up. On random occassions, on start up, the engine light would stay on, I would get error messages in the msg center (stability tract, transaction control, transmission, tire monitor, etc), the gauges would be jumping all over the place and if driven, the transmission would shift very hard.

The dealer looked it and determined that it was a wire that was streatched too far and not making good connection (wink wink - meaning they found nothing else). The computer did show error codes of U012, U0100, U0101, U0146, U0073 & U0122.

Once back from the dealer the suburban was fine for 3 weeks. Then out of the blue it happened again. Most of the time I can turn off the car, wait 30 secs, restart it and it seems to reset itself and all is fine again.

Last night it was really confused. The Auto-extending running boards would not deploy until after the engine was started. The msg center was ging all of the error messages again. I turned it off but then it would not crank at all. Waited another 30 mins and then it started, stumbled and then died. By the 5th time of trying to restart, everyting was fine and have not had issues since.

It is definietly not a lose wire as the dealer had hoped. It only does it on start up and never while underway. It must be computer related if I can reset the system by shutting down and restarting.

Please help. Very frustrated owner. Would appreciate any advice you have that I can relay back to the dealer to resolve this.

Thanks!

 

I would think it would be the BCM (body control module) not the ECM. The ECM controls engine, and engine components. The BCM controlls mainly accesories, and body stuff, ex: headlights, A/C, etc...)

 

All the DTC that you mentioned indicate a lost of communications between the ECM, TCM (xmission) with the gateway on the CAN medium speed bus. I see a loss communication code that deals with vehicle stability system as well. Sometimes these comm codes will be set during start up if the system does not go through a proper startup or shutdown. My guess will be a loose wiring (sometimes the pins to the connectors are bent causing intermittent failure or possibly the gateway (interface) box. Good luck- I am taking a delivery of a 2008suburban 1LT next week.

 

I was just wondering if you figured out what was going on with these issues. What was the fix???

Thanks