Two problems related to automatic transmission control module have been reported for the 2015 GMC Sierra 2500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2015 GMC Sierra 2500 based on all problems reported for the 2015 Sierra 2500.
Shifting started to make a loud clunking sound. Then the vehicle wouldn't shift out of 3rd gear. The engine check light came on and the code determined it to be a faulty transmission control module (tcm). When looking at the tcm, I also noted that the tcm was very hot and the nearby cable cover had melted. When researching the issue, it was discovered that GMC Sierra 2500 and 3500, years 2009 - 2015 were having this same issue all over the continent. Resulting in a massive back order and leaving drivers stranded. There was no warning lights or sounds before my power train froze up.
Transmission control module failure; the truck at 45 mph developed a complete loss of all gauges(tach, speed, fuel, temp) and then 10-15 seconds later two loud noises followed by the vehicle coming to a rapid deceleration. This resulted in the wheels locking up and sliding sidewise. The truck rolled up on to its left two wheels and then slammed down. If this occurred at 75mph on the highway, the truck would have rolled. The truck has been at a GMC dealership since then. GMC has no date of if or when this truck can be repaired. The "tcm" is defective. It was on a city street, 45 mph zone going straight down a gentle grade.
| Power Train problems | |
| Automatic Transmission Control Module problems |