Tap a category to read its complaints. One report may name several components.
When problems were reported
Mileage at the reported incident
Limited mileage data: 9 of 11 reports include usable mileage. There isn’t enough coverage to show a useful chart.
NHTSA’s mileage field refers to the reported incident, not necessarily the filing date. This shows report counts, not the likelihood of a failure.
What to inspect
Issues worth paying extra attention to based on owner reports.
Engine. Review the 6 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
Forward Collision Avoidance. Review the 2 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
Service Brakes. Review the 2 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
NHTSA owner reports · September 18, 2026 snapshot.
0 crash reports0 fire reports0 injury reports
What owners actually said
11 reports
99,000 miles · Sep 14, 2026
Forward Collision Avoidance
The contact owns a 2020 GMC Sierra Denali. The contact stated that while driving with Adaptive Cruise Control set to 55 MPH, the vehicle suddenly accelerated. The contact depressed the brake pedal to disengage the Adaptive Cruise Control settings, preventing the vehicle from crashing into the vehicle ahead. The contact stated th…
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The contact owns a 2020 GMC Sierra Denali. The contact stated that while driving with Adaptive Cruise Control set to 55 MPH, the vehicle suddenly accelerated. The contact depressed the brake pedal to disengage the Adaptive Cruise Control settings, preventing the vehicle from crashing into the vehicle ahead. The contact stated that the failure had occurred while the Adaptive Cruise Control was engaged. The approximate failure mileage was 99,000.
NHTSA ODI #11764047
25,000 miles · Sep 11, 2026
Engine
The contact owned a 2020 GMC Sierra Denali. The contact stated that while the vehicle was parked, there was an abnormal knocking sound coming from the engine compartment. The check engine warning light was intermittently illuminated. The vehicle was taken to a dealer; however, the cause of the failure was not yet determined. The…
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The contact owned a 2020 GMC Sierra Denali. The contact stated that while the vehicle was parked, there was an abnormal knocking sound coming from the engine compartment. The check engine warning light was intermittently illuminated. The vehicle was taken to a dealer; however, the cause of the failure was not yet determined. The dealer advised the contact to purchase a new vehicle because the engine would eventually need to be replaced. The contact stated that at approximately 3,000 miles, there was an abnormal odor oil burning odor coming from the vehicle. The contact stated that the vehicle was consuming an excessive amount of engine oil and approximately 5 quarts needed to be added between scheduled oil changes. The failure mileage was approximately 25,000.
NHTSA ODI #11763621
98,500 miles · Jun 16, 2026
Engine
The contact owns a 2020 GMC Sierra 1500 Denali. The contact stated that while parking the vehicle, there was an abnormal grinding sound coming from the engine. There was no warning light illuminated. The local dealer was contacted about the failure; however, the vehicle was not diagnosed or repaired. The manufacturer was not mad…
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The contact owns a 2020 GMC Sierra 1500 Denali. The contact stated that while parking the vehicle, there was an abnormal grinding sound coming from the engine. There was no warning light illuminated. The local dealer was contacted about the failure; however, the vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 98,500.
NHTSA ODI #11744588
190,000 miles · Nov 18, 2025
Engine And Engine Cooling
The contact owns a 2020 GMC Sierra Denali. The contact stated that while stopped at a traffic light with the brake pedal depressed, the vehicle shut off unexpectedly. There was no warning light illuminated. The contact made several attempts to restart the vehicle; however, the vehicle failed to restart. Due to the failure, the v…
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The contact owns a 2020 GMC Sierra Denali. The contact stated that while stopped at a traffic light with the brake pedal depressed, the vehicle shut off unexpectedly. There was no warning light illuminated. The contact made several attempts to restart the vehicle; however, the vehicle failed to restart. Due to the failure, the vehicle was towed to the dealer where a diagnostic test was performed. The contact was later informed that the engine had seized due to engine bearing failure, and the contact was provided an estimate for a new engine. Upon investigation, the contact discovered NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling) and linked the recall to the failure. The manufacturer was notified about the failure and the recall, and the contact was informed that the VIN was not included in the recall. The vehicle was not repaired and remained with the dealer. The failure mileage was approximately 190,000.
NHTSA ODI #11700178
6,700 miles · Nov 9, 2023
Forward Collision Avoidance
The contact owns a 2020 GMC Sierra Denali. The contact stated while driving 75 MPH, the Adaptive Cruise Control feature became inoperable. The contact stated that when the vehicle got too close to another vehicle, the Adaptive Cruise Control feature failed to activate as designed. The vehicle was not diagnosed or repaired by an …
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The contact owns a 2020 GMC Sierra Denali. The contact stated while driving 75 MPH, the Adaptive Cruise Control feature became inoperable. The contact stated that when the vehicle got too close to another vehicle, the Adaptive Cruise Control feature failed to activate as designed. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 6,700. The VIN was unavailable.
NHTSA ODI #11554317
Mileage unknown · Apr 26, 2023
Electrical System
The contact owns a 2020 GMC Sierra Denali. The contact stated while driving 65 MPH at night, the vehicle stalled and the “Shift to Neutral and Restart Vehicle” message was displayed. The contact was unable to restart the vehicle and was unable to visibly see the roadway. The contact was able to park on the side of the road. The …
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The contact owns a 2020 GMC Sierra Denali. The contact stated while driving 65 MPH at night, the vehicle stalled and the “Shift to Neutral and Restart Vehicle” message was displayed. The contact was unable to restart the vehicle and was unable to visibly see the roadway. The contact was able to park on the side of the road. The vehicle was not drivable. The contact towed the vehicle to his residence, and then to the local dealer the next day, where the vehicle was diagnosed with needing the starter to be replaced. The vehicle was repaired. The manufacturer had not been informed of the failure. The failure mileage was unknown.
NHTSA ODI #11519126
20,000 miles · Nov 23, 2021
Engine
The contact's father owns a 2020 GMC Sierra Denali 3500. The contact stated that while his father was driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was taken to the dealer and diagnosed with a cylinder #1 misfire. The vehicle was repaired; however, the failure recurred. The vehicle was …
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The contact's father owns a 2020 GMC Sierra Denali 3500. The contact stated that while his father was driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was taken to the dealer and diagnosed with a cylinder #1 misfire. The vehicle was repaired; however, the failure recurred. The vehicle was then taken to Wackerli Auto Center (1363 N Holmes Ave, Idaho Falls, ID 83401) on numerous occasions and diagnosed with a faulty sensor. The dealer replaced the sensor; however, the failure recurred. The vehicle was not repaired and remained at the dealer. The manufacturer was made aware of the failure. The failure mileage was approximately 20,000. The VIN was unavailable.
NHTSA ODI #11441449
3,000 miles · Apr 7, 2021
Service Brakes
BRAKES SQUEAK. STARTED ABOUT 3000 MILES. I HAVE COMPLAINED TO DEALER SEVERAL TIMES.
NHTSA ODI #11406920
Mileage unknown · Dec 16, 2020
Engine
KNOCKING COMING FROM ENGINE - NOTICEABLE UNNECESSARY NOISE IN WHICH DEALER CAN NOT FIX THE PROBLEM
NHTSA ODI #11383781
350 miles · Oct 29, 2020
EngineService Brakes
TWO ISSUES BROKEN VALVE SPRING CAUSED ENGINE TO SHUT DOWN, SECOND SERVICE BRAKE, BRAKE FAILURE LIGHT, SERVICE ESC, SERVICE TRAILER BRAKE MESSAGES CAUSING BRAKE FAILURE
NHTSA ODI #11367036
Official recalls
0
No recalls in this snapshot.
Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗
NHTSA investigations
0
No exact-year investigations in this snapshot.
2020 GMC Sierra Denali Problems, Complaints & Recalls | Skip That Year