2021 GMC Sierra 1500 Transmission Problems

Which parts fail

• Automatic transmission › Internal › Shaft › Output
  1

Components named in complaints (automatic and manual transmissions, CVT, axles, driveshaft, 4WD/AWD).

Mileage when the problem started

• Under 25k
  418%
• 25k–50k
  418%
• 50k–75k
  523%
• 75k–100k
  314%
• 100k–150k
  627%
• 150k+
  00%

Owner reports

Selected complaints filed with NHTSA by 2021 GMC Sierra 1500 owners, lightly cleaned up (personal details are redacted by NHTSA).

The contact owns a 2021 GMC Sierra 1500. The contact stated while driving at approximately 20 MPH, the vehicle lost motive power. The contact stated that the accelerator pedal was depressed; however, the vehicle failed to respond as needed. The contact moved the transmission lever from drive(D) to neutral(N) to reverse(R) several times and was able to drive back to the residence. The contact stated that the check engine warning light was illuminated. The contact had the vehicle towed to a local dealer. The dealer diagnosed the failure and determined that the transmission control valve had failed and needed to be replaced. The vehicle was repaired; however, the contact stated that the failure had reoccurred. The vehicle was taken back to the same dealer who advised that the transmission control valve had failed, but the parts needed to complete the repair were on back-order. …

The contact owns a 2021 GMC Sierra 1500. The contact stated while driving at various speeds and depressing the accelerator pedal, the vehicle hesitated to respond and shuddered. The vehicle was taken to the dealer, where the fuel tank was cleaned, and the contact added fuel treatment to the fuel, as recommended by the dealer; however, the failure recurred. The contact stated that while driving from a complete stop, uphill, and while driving 50 MPH, the vehicle shuddered and experienced erratic transmission shifting. The check engine warning light was illuminated. The vehicle was taken to Dixie Buick GMC (14565 S Tamiami Trl, Fort Myers, FL 33912); where it was determined that the vehicle was experiencing a abnormal shudder. The dealer replaced the transmission fluid; however, the failure persisted. …

The contact owns a 2021 GMC Sierra 1500. The contact stated while driving 75 MPH, the vehicle jerked and downshifted to overdrive. The message "Engine Power Reduced" was displayed on the instrument panel. The driver depressed the accelerator pedal, but the vehicle failed to exceed 4 MPH. The vehicle was taken to the dealer, where it was diagnosed that the valve body failed, which caused the transmission to fail. The vehicle was repaired. While the contact was driving home after the vehicle was picked up, the vehicle jerked and hesitated. The dealer was contacted and informed the contact that if the check engine warning light becomes illuminated the vehicle could be diagnosed. After several days, the check engine warning light illuminated, and the vehicle was taken to the dealer where it was diagnosed that the shutter valve had failed and needed to be replaced. The vehicle was repaired. …

The contact owns a 2021 GMC Sierra 1500. The contact stated that the transmission was previously replaced. The contact stated that 20,000 miles later, the vehicle started to experience erratic hard shifting while driving at various speeds, and the vehicle failed to respond upon shifting into reverse(R). The vehicle was towed to the dealer, where the battery was replaced; however, the failure recurred. The contact received notification of NHTSA Campaign Number: 24V797000 (Power Train). The vehicle was towed back to the dealer, where it was determined that the transmission needed to be replaced. The contact was advised that the repair was not covered under the extended warranty coverage associated with the recall because the required DTC was not retrieved. …

The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign number: 24V797000 (POWER TRAIN), and the dealer performed an interim repair on the vehicle. In March 2025 the part was available, and the recall repair was completed. The contact stated that on one occasion, while driving at an undisclosed speed and then coming to a complete stop, the vehicle jerked and the transmission unexpectedly downshifted. The message "Low Power Mode" was displayed on the instrument panel. The vehicle then failed to accelerate as intended while depressing the accelerator pedal. The contact drove to a parking lot and turned off the vehicle. The vehicle was towed to Don Moore Chevrolet GMC, where it was diagnosed with transmission control valve failure. The contact was informed it would be months before the repair could be performed. …

The contact owns a 2021 GMC Sierra 1500. The contact stated while driving at various speeds and downshifting, the rear wheels locked up with the parking brake warning light flashed on the instrument panel. The vehicle would resume normal operation soon after the failure. The vehicle was taken to a dealer where the contact was informed that there was a pending NHTSA Campaign Number: 24V797000 (Power Train) on the vehicle for the failure. The contact was informed that there was a temporary fix on the vehicle to repair the defect. After the temporary fix was performed, the contact experienced the failure twice within a week. The contact received a call that the permanent fix was available; however, soon after the repair was performed, the failure immediately occurred upon leaving the dealer. …

The contact owns a 2021 GMC Sierra 1500. The contact stated while the vehicle was parked, the contact attempted to turn off the vehicle; however, the vehicle remained running. A message was displayed to shift to park(P). The contact stated that the lights, radio, and other functions remained operational. On another occasion, the vehicle jerked, and the steering was difficult to turn. The dealer was contacted; however, the vehicle had not been taken to be diagnosed or repaired. The contact also stated that the trunk failed to fully close. The message that the trunk was open was displayed. The contact attempted to close the trunk and message on the displayed was turned off; however, the trunk remained slightly open. The vehicle was not taken to be diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 63,315.

The contact owns a 2021 GMC Sierra 1500. The contact stated while driving at an undisclosed speed, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. The contact stated that the rear of the vehicle was shuddering and shaking. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. The contact stated that over time the failure became more persistent. The contact was concerned because two small children were seated in the rear of the vehicle daily. The manufacturer was made aware of the failure but provided no assistance. The contact referenced NHTSA Campaign Number: 24V797000 (Power Train); however, the contact was informed that the VIN was not included in the recall. The failure mileage was approximately 61,000.

The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 24V797000 (Power Train); however, the dealer was unable to complete the recall and returned the vehicle to the contact in a worse condition than when the contact had dropped the vehicle off at the dealer. The contact stated that while attempting to drive the vehicle off the dealer parking lot, the check engine and reduced power warning lights flashed on the instrument cluster. The contact stated that he returned the vehicle to the dealer and was informed that the vehicle could not be repaired. The manufacturer was not made aware of the issue. The failure mileage was approximately 114,000.

The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 24V797000 (POWER TRAIN); however, the part to do the recall repair was unavailable. The local dealer was contacted, and it was confirmed that the part was not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The contact stated that the transmission was shifting hard while driving. The local dealer was notified of the failure. The cause of the failure was not yet determined. The manufacturer was not made aware of the issue. The failure mileage was 120,000. VIN tool confirms parts not available.

Related recalls

Transmission complaints in other Sierra 1500 years