2021 GMC Sierra 2500 Transmission and drivetrain Problems
- Complaints
- 13about this part
- Share
- 25%of 52 total for the year
- Median mileage
- 50,000miles
- Trend
- Not enough dataFewer than 15 complaints, too few for a reliable trend.
NHTSA recorded 13 complaints about the transmission and drivetrain of the 2021 GMC Sierra 2500, 25% of the 52 complaints for this model year. Where a mileage was given, the median is 50,000 miles. 1 of these say a crash was involved, according to the filers. 1 recall campaign on record is filed under a similar system.
Fewer than 15 complaints name this part, so treat the figures as a rough indication only.
Example complaints
Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.
“The owns a 2021 GMC Sierra 2500. The contact stated while driving 70 MPH, the RPM revved up to 6,000 RPM. Additionally, the vehicle lost motive power. The vehicle was taken to the dealer, who informed the contact that the transmission needed to be replaced. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was 47,000. The VIN was not available.”
NHTSA complaint #11526772, filed 2023-06, 47,000 miles“We keep getting an error message that shows we need to service DEF SYSTEM, it also started to limit my MPH and is now locked at 55 MPH. initial check of the DEF SYSTEM shows a malfunctioning module. it has been happening over the last year to 18 months. they would reset it or it would sometimes go away on its own after having to drive it in order for the error to clear.”
NHTSA complaint #11741364, filed 2026-06“While driving on the highway at normal speed, my vehicle was operating completely normally with no warning lights, messages, or prior issues. Without any warning, the vehicle suddenly lost the ability to accelerate and felt as if it had been shifted into neutral. I immediately had to pull over to the side of the highway, as this created a dangerous situation with surrounding traffic. The vehicle had to be towed to a mechanic. …”
NHTSA complaint #11726714, filed 2026-03“I am reporting repeated failures involving both the transmission and diesel emissions (DEF) system on my 2021 GMC Sierra 2500HD Denali equipped with the 6.6L Duramax diesel engine and Allison 10-speed automatic transmission. While under warranty, the truck required replacement of the aftertreatment fuel injector and later the Reductant Control Module due to DEF/emissions system failures. General Motors also completed recall-related transmission software updates on the vehicle. …”
NHTSA complaint #11746749, filed 2026-06“Pulling into a driveway and the truck made a loud clunk and the check engine light, traction control light, and a reduced engine power light came on and the truck came to an abrupt stop. When the gear shift was put into reverse or any forward gear the truck would rev up without touching the gas pedal. The left rear wheel locked up. After paying over $700 in tow bills to get the truck towed to our house and then to the dealer we were told that the transmission had a catastrophic internal failure. This truck only has 82,000 miles on it and is a 2021!”
NHTSA complaint #11703711, filed 2025-12Related recalls
- 24V797000Oct 24, 2024General Motors, LLC (GM) is recalling certain 2020-2022 Chevrolet Silverado 1500, 2500, 3500, GMC Sierra 1500, 2500, 3500, 2021 Cadillac Escalade, Escalade…Covers: GMC Sierra 2500 2020–2022, Sierra 3500 2020–2022, Sierra 1500 2020–2022 +9 more
Related service bulletins
- 11024189Oct 9, 2025Certain vehicles listed above, may have a condition where the transmission control valve has worn, resulting in a gradual loss of pressure within the valve. The effects can cause…
- 11026024Jun 3, 2025This bulletin helps aid the tech in possible 10L100 transmission noise that may be normal or abnormal depending on the concern noted.
- 11023369May 16, 2025This service bulletin advises the technician to check if the transmission cooler lines are twisted to correct customer concerns of Harsh Shift, Shudder, Surge, Stall…
- 11020259May 8, 2025This technical bulletin provides a procedure to inspect the front pump of the transmission for a possible leak.
- 11019516Apr 17, 2025This preliminary informational (PI) bulletin provides information to dealership personnel that may be helpful when addressing underbody component corrosion with customers.
- 11017255Mar 25, 2025This service bulletin helps diagnose/reduce possible CCND issues on Transfer Cases - Service 4WD on DIC, Intermittent Failures, Noise Concerns, Driveline/Steering…
- 11013150Jan 28, 2025Certain vehicles listed above, may have a condition where the transmission control valve has worn, resulting in a gradual loss of pressure within the valve. The effects can cause…
- 11013069Jan 9, 2025This bulletin provides information on identifying Non-GM Engine Calibrations for Gasoline Engines using the Tech 2 or GDS 2.
- 11012943Jan 9, 2025This Preliminary information communicates a possible retainer ring dis-lodged for a DTC P2714, may not have reverse as well.
- 11011880Dec 17, 2024Certain vehicles listed above, may have a condition where the transmission control valve has worn, resulting in a gradual loss of pressure within the valve. The effects can cause…
Transmission and drivetrain: other model years
| Year | Complaints | Share of year |
|---|---|---|
| 2026 | 1 | 8% |
| 2025 | 3 | 11% |
| 2024 | 27 | 25% |
| 2023 | 20 | 61% |
| 2022 | 7 | 16% |
| 2021 | 13 | 25% |
| 2020 | 25 | 31% |
| 2019 | 2 | 6% |
| 2018 | 3 | 9% |
| 2017 | 6 | 16% |
| 2016 | 1 | 2% |
| 2015 | 8 | 9% |
| 2014 | 3 | 10% |
| 2013 | 5 | 11% |
| 2012 | 4 | 13% |
| 2011 | 6 | 10% |
| 2008 | 3 | 5% |
| 2007 | 2 | 2% |
| 2006 | 12 | 18% |
| 2005 | 7 | 6% |
| 2004 | 9 | 6% |
| 2003 | 13 | 8% |
| 2002 | 14 | 10% |
| 2001 | 6 | 4% |
| 2000 | 1 | 2% |
| 1999 | 1 | 3% |
| 1998 | 3 | 20% |
Other parts of the 2021 GMC Sierra 2500
9 complaintsEngine
8 complaintsBrakes
7 complaintsElectrical system
6 complaintsBody and structure
5 complaintsLatches, locks and linkages
4 complaintsForward collision avoidance
3 complaintsOther or unknown
3 complaintsAir bags
2 complaintsFuel system
2 complaintsBack-over prevention (rear camera)
1 complaintsLane departure
1 complaints
← All problems reported for the 2021 GMC Sierra 2500
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 30, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.
To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology