Table 1 shows two common power train related problems of the 2020 GMC Sierra 3500. The number one most common problem is related to the power train (18 problems). The second most common problem is related to the automatic transmission control module (one problem).
| Problem Category | Number of Problems |
|---|---|
| Power Train problems | |
| Automatic Transmission Control Module problems |
The contact owns a 2020 GMC Sierra 3500. The contact stated that while driving at an undisclosed speed, the vehicle inadvertently went into limp mode. There was no warning light illuminated. The vehicle was taken to the dealer, where it was diagnosed that the transmission valve body sensor had Read details...
My truck has been exhibiting hard downshifting at certain speeds, when the powertrain loads up such as a grade change, and requires a downshift. I have complained about this issue to the dealership as early as 2022, and 33,185 miles. The dealership made me pay for a transmission $388. Read details...