I am having a similar problem with my 2008 GXP. Not all the time, but becoming more frequent, when I start from a complete stop, the car hesitates and then jerks really hard. Shifting thru the other gears is just fine. I have also noticed it when going in reverse from a dead stop. Sometimes the jolt is worse than others and it feels like the tranny is going to break. I have taken it in to the dealer multiple times now (including today) for them to tell me that they cannot duplicate the issue and that its not showing any codes in their computer. But I know its a real issue and don't know what else to do to get them to fix this or at least acknowledge that there is a problem. I can't keep wasting my time taking it in to the dealer all the time just for them to tell me that they cannot duplicate it. It is a very frequent issue and I'm surprised that they have not been able to duplicate it yet. I know that I have plenty of the 100,000 mile powertrain warranty left, but the issue is annoying and I also worry that it will just break completely and leave me stranded somewhere. I did some research tonight and there is a technical service bulletin# 080730002 regarding harsh shifts and slips. Summary as follows:
INFORMATIONAL ON 4T65-E MN7, M15 AND M76 FRONT WHEEL DRIVE AUTOMATIC TRANSMISSION VALVE BODY RECONDITIONING, DTCS P0741, P0742, P0757, P842, HARSH SHIFTS OR SLIPS. ( NHTSA ITEM NUMBER - 10025065 )
What does this mean? Will they fix this issue or is it just an informational bulletin showing that this has been known to occur but no fix is required? I am going to call them in the morning to ask them about it. I'm going to be pissed if all along, there was a known issue with this and they kept making me waste my time with multiple visits to the service dept. They gave me the impression so far that they think I am being stupid and there is not really a problem.
