2020 GMC Sierra 1500 electrical system problems
79 owner complaints filed with NHTSA name the electrical system on the 2020 GMC Sierra 1500 — 17% of all complaints for this model year.
What owners report
“5/5/25 woke up back seat entire truck flooring soaking wet back glass cracked. 4/8/25 transmission went out 117,000 miles 7/3/25 exhaust leak and placed nox 1. 7/8/25 127551 mileage exhaust leak replace gaskets, belt , tensioner, and pulley, 6/8/2025 3 knock sensors replaced and replaced intake…”
filed Sep 15, 2026
“Our 2020 GMC SIERRA 1500 has suffered catastrophic systems and engine failure including the brakes multiple times for almost 4 years. It has happened in high traffic and on the interstate each time having to be coasted off of the road to come to a rolling stop. There have been nine repair attempts…”
filed Aug 24, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Related recalls
- Battery positive (B+) cable rings may have been manufactured with excessive glue…Campaign 19V888000 · Dec 12, 2019
Electrical System problems in other Sierra 1500 years
| Year | Reports | Share |
|---|---|---|
| 2026 Sierra 1500 | 12 | 10% |
| 2025 Sierra 1500 | 25 | 22% |
| 2024 Sierra 1500 | 41 | 11% |
| 2023 Sierra 1500 | 61 | 13% |
| 2022 Sierra 1500 | 82 | 14% |
| 2021 Sierra 1500 | 73 | 13% |
| 2019 Sierra 1500 | 95 | 15% |
| 2018 Sierra 1500 | 43 | 14% |
| 2017 Sierra 1500 | 54 | 15% |
| 2016 Sierra 1500 | 54 | 16% |
| 2015 Sierra 1500 | 96 | 13% |
| 2014 Sierra 1500 | 128 | 17% |
Other reported problem areas on the 2020 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.