I have have a '06' G6 GTP Hardtop convertible. Engine spontaneously shuts off and ABS light comes on every time I hit a speed bump, drive over railroad tracks, hit a pot hole. etc. Basically, every time I hit some sort of big bump on the road. When this happens, I would pull over the road, put it in park, and try to restart the engine. But, I would have to try several times before the car turns over. I would put car in total stop, park, turn off key, and wait a few seconds before restarting car. Sometimes it starts right up, other times would take a few attempts. It's almost like I need to wait for the car to reset itself. There is power when restarting, but it would not turn over immediately. Not even a starter sound or engine crank. It has gotten worse over the past week and and my car is shutting off more often. This has become hazardous especially driving on a thru-way.

I did take the car to a Pontiac dealer about a year ago to address this problem. The dealer changed out the electrical unit to a tune of $600.00. I brought the car back to dealer for same issue, and was basically told they could not find anything wrong with the car.