I hope I have the answer:
I took my car in this week for the "Check Engine" light; I also mentioned the OnStar problem. The service advisor kind of groaned, and said they'd had issues with the upgrade. I was thinking nothing might happen, until I picked up the car.
It appears that OnStar needs to upgrade the software AFTER the digital upgrade is installed. I called OnStar to ask how the transmission was doing, and they said they could see no issues. They also said they could connect to it!
Here's the details of the repair from my repair invoice, typed in verbatim:
CUST STATES ON STAR CAN NOT READ CODES FROM CAR
CAUSE: UPDATE PROGRAM TAC 10422709 FOR ECM
J6354 POWERTRAIN CONTROL MODULE ENGINE
REPROGRAMMING WITH SPS
..23831 UPDATED SOFTWARE. HAVE OVER AN HOUR IN THE REPAIR. CALLED ONSTAR AND VERIFIED THAT THEY CAN NOT READ ECM CODES. CALLED TAC AND OPEN CASE # 10422709. THEY TOLD ME THAT ONSTAR HAD TO UPDATE THE SOFTWARE. TALKED TO TAC 2 MORE TIMES BEFORE ONSTAR UPGRADED THE SOFTWARE.
I hope this information is helpful!!!!!
So far, everything seems to be working - I'll get my next email from OnStar about my car and it's systems on September 4, so I'll know for sure then.
BTW, if you do get those emailed reports, check them out! You can get all the history of the car, average miles driven, when the oil was changed and other information by clicking on the included links. I think it's pretty cool!
Last edited by homegameroom; 08-09-2008 at 07:27 AM.