2020 GMC SIERRA DENALI

9 complaints filed with NHTSA.

9
Complaints
0
Crashes
0
Fires
0
Injuries
0
Deaths

Complaints by Component

ComponentCount
ENGINE4
SERVICE BRAKES2
ELECTRICAL SYSTEM:STARTER ASSEMBLY1
FORWARD COLLISION AVOIDANCE: ADAPTIVE CRUISE CONTROL:SOFTWARE1
ENGINE AND ENGINE COOLING1

Recent Complaints

20251118ENGINE 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 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 con

Mileage: 190,000

20231109FORWARD COLLISION AVOIDANCE: ADAPTIVE CRUISE CONTROL:SOFTWARE

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.

Mileage: 6,700

20230426ELECTRICAL SYSTEM:STARTER ASSEMBLY

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

20211123ENGINE

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; ho

Mileage: 20,000

20210407SERVICE BRAKES

BRAKES SQUEAK. STARTED ABOUT 3000 MILES. I HAVE COMPLAINED TO DEALER SEVERAL TIMES.

Mileage: 3,000

20201216ENGINE

KNOCKING COMING FROM ENGINE - NOTICEABLE UNNECESSARY NOISE IN WHICH DEALER CAN NOT FIX THE PROBLEM

20201029SERVICE 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

Mileage: 350

20201029ENGINE

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

Mileage: 350

20201008ENGINE

I NOTICED SEVERAL SPOTS OF OIL ON MY DRIVEWAY, I THEN INSPECTED THE UNDERSIDE OF THE ENGINE (L5P) AND NOTICED OIL DRIPPING FROM SEVERAL BOLTS AND LINES. MY VEHICLE, A 2020 2500HD DENALI DIESEL, HAS ONLY 2,200 MILES ON IT FROM NORMAL HIGHWAY DRIVING.

Mileage: 2,200