Turn Signal Flasher Unit problems of the 2001 GMC Jimmy

At 12,270 miles we had no brake lights taken to the dealer and he replaced the turn signal and said that was the problem. That was in June. On July 6, 2001 the dash board lights flashed several times lighting all of the guages showing that the engine was not running, but it was still running. Engine light stayed on. Took the vehicle to the dealer who found multiple trans dtc's internal failure replace ignition switch and performed relearn. I am concerned that this vehicle will have more defects, please let me know if others are having the same problem. Thank you.