2021 GMC Sierra 1500 electrical system problems
71 owner complaints filed with NHTSA name the electrical system on the 2021 GMC Sierra 1500 — 13% of all complaints for this model year.
What owners report
“I am submitting supplemental evidence regarding my 2021 GMC Sierra (VIN [XXX]) for Recall Query RQ26001, Campaign 25V-274. Despite multiple repair attempts, my vehicle remains unsafe and non-compliant with GM Service Bulletin N252494002. The recall remedy was performed deficiently. [XXX] Northeast…”
filed Jul 14, 2026
“I own a 2021 GMC Sierra AT4 3.0L Duramax (VIN [XXX]). The vehicle has codes P1098 (Coolant Control Valve Performance) and P129F which coincides with the first code. My dealer believes this is consistent with an Engine Coolant Control Valve failure. I understand Special Coverage XXX exists for this…”
filed Jul 7, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Electrical System problems in other Sierra 1500 years
| Year | Reports | Share |
|---|---|---|
| 2026 Sierra 1500 | 8 | 12% |
| 2025 Sierra 1500 | 21 | 23% |
| 2024 Sierra 1500 | 39 | 12% |
| 2023 Sierra 1500 | 55 | 13% |
| 2022 Sierra 1500 | 79 | 15% |
| 2020 Sierra 1500 | 77 | 17% |
| 2019 Sierra 1500 | 94 | 15% |
| 2018 Sierra 1500 | 42 | 14% |
| 2017 Sierra 1500 | 54 | 15% |
| 2016 Sierra 1500 | 54 | 16% |
| 2015 Sierra 1500 | 93 | 13% |
| 2014 Sierra 1500 | 128 | 17% |
Other reported problem areas on the 2021 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.