2015 GMC Sierra 1500 power train problems
95 owner complaints filed with NHTSA name the power train on the 2015 GMC Sierra 1500 — 13% of all complaints for this model year.
What owners report
“For no apparent reason the truck goes into “low power mode” and gives off code p2138 often happens around 30-35 mph. Have had it happen to me also around 45 mph also. I have replaced sensors and parts to which a month or so goes by and it happens again.”
filed May 26, 2026
“During day to day driving when the truck is accelerating from a stopped position there's a massive clunk or hard shift from either 1st to 2nd gear. have also heard similar complaints from other 2015 sierra 1500 owners saying the transmission is having a hard shift on acceleration from a stop. Have…”
filed Feb 18, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Power Train problems in other Sierra 1500 years
| Year | Reports | Share |
|---|---|---|
| 2026 Sierra 1500 | 17 | 25% |
| 2025 Sierra 1500 | 20 | 22% |
| 2024 Sierra 1500 | 64 | 20% |
| 2023 Sierra 1500 | 81 | 19% |
| 2022 Sierra 1500 | 100 | 18% |
| 2021 Sierra 1500 | 129 | 24% |
| 2020 Sierra 1500 | 88 | 20% |
| 2019 Sierra 1500 | 129 | 21% |
| 2018 Sierra 1500 | 125 | 43% |
| 2017 Sierra 1500 | 116 | 33% |
| 2016 Sierra 1500 | 83 | 25% |
| 2014 Sierra 1500 | 68 | 9% |
Other reported problem areas on the 2015 GMC Sierra 1500
Counts are unique NHTSA complaints naming this component group. Complaints are unverified owner reports; mileage is computed only from complaints that included a usable odometer reading.