2020 Gmc SIERRA DENALI: complaints, problems and recalls
Explore the records behind recurring owner reports.
Key facts
9 owner complaints analyzed
0 distinct recall campaigns
6,700 mi median reported failure mileage
Scope: 2020 model year. Data snapshot: . 7 complaints include usable failure mileage.
This selection has limited data. It remains available for lookup but is excluded from search indexing.
Most common problems
Engine is the most frequently named component, appearing in 5 of 9 complaints (55.6%). A complaint can name multiple components.
| Topic | Matching reports | Share of complaints |
|---|---|---|
| Braking behavior | 3 | 33.3% |
| Engine operation | 1 | 11.1% |
Topic matches use published keyword rules. They describe mentions, including negations or comparisons, and do not confirm a diagnosis. Read the matching rules.
Component breakdown
Number of unique complaints naming each component. Top eight shown.
| Category | Count |
|---|---|
| Engine | 5 |
| Service Brakes | 2 |
| Electrical System:Starter Assembly | 1 |
| Engine And Engine Cooling | 1 |
| Forward Collision Avoidance: Adaptive Cruise Control:Software | 1 |
Engine: 5; Service Brakes: 2; Electrical System:Starter Assembly: 1; Engine And Engine Cooling: 1; Forward Collision Avoidance: Adaptive Cruise Control:Software: 1
Reported problems by failure mileage
Complaint counts in mileage bands. These are not failure rates per vehicle or mile.
| Category | Count |
|---|---|
| Under 25,000 | 5 |
| 25,000 to 49,999 | 0 |
| 50,000 to 74,999 | 0 |
| 75,000 to 99,999 | 1 |
| 100,000 to 149,999 | 0 |
| 150,000 and above | 1 |
Under 25,000: 5; 25,000 to 49,999: 0; 50,000 to 74,999: 0; 75,000 to 99,999: 1; 100,000 to 149,999: 0; 150,000 and above: 1
Under 25,000 miles has the most reports with usable mileage (5). 2 complaints have missing, zero or invalid mileage.
Complaints over time
Year the complaint was filed, not the vehicle model year or incident year. The snapshot year is partial.
| Category | Count |
|---|---|
| 2020 | 3 |
| 2021 | 2 |
| 2023 | 2 |
| 2025 | 1 |
| 2026 | 1 |
2020: 3; 2021: 2; 2023: 2; 2025: 1; 2026: 1
Pattern summary
Engine leads the component reports. Braking behavior appears in 3 complaint narratives. Engine operation appears in 1 complaint narratives. Use these patterns to inspect individual reports and prepare questions for a mechanic.
Calculated from recorded counts. An AI narrative has not been published for this selection.
Examples from the source records
Examples provide context, not a representative sample or a verified diagnosis.
Owner report 11363419 · 2020-10-08 (October 8, 2020)
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.
Owner-reported narrative. 2,200 miles reported. Look up ODI 11363419 at NHTSA ↗
Owner report 11367036 · 2020-10-29 (October 29, 2020)
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
Owner-reported narrative. 350 miles reported. Look up ODI 11367036 at NHTSA ↗
Owner report 11383781 · 2020-12-16 (December 16, 2020)
KNOCKING COMING FROM ENGINE - NOTICEABLE UNNECESSARY NOISE IN WHICH DEALER CAN NOT FIX THE PROBLEM
Owner-reported narrative. Look up ODI 11383781 at NHTSA ↗
Owner report 11406920 · 2021-04-07 (April 7, 2021)
BRAKES SQUEAK. STARTED ABOUT 3000 MILES. I HAVE COMPLAINED TO DEALER SEVERAL TIMES.
Owner-reported narrative. 3,000 miles reported. Look up ODI 11406920 at NHTSA ↗
Owner report 11441449 · 2021-11-23 (November 23, 2021)
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 r…
Owner-reported narrative. 20,000 miles reported. Look up ODI 11441449 at NHTSA ↗
Owner report 11519126 · 2023-04-26 (April 26, 2023)
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 …
Owner-reported narrative. Look up ODI 11519126 at NHTSA ↗
Owner report 11554317 · 2023-11-09 (November 9, 2023)
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.
Owner-reported narrative. 6,700 miles reported. Look up ODI 11554317 at NHTSA ↗
Owner report 11700178 · 2025-11-18 (November 18, 2025)
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. Up…
Owner-reported narrative. 190,000 miles reported. Look up ODI 11700178 at NHTSA ↗
Recall history
0 distinct campaigns affect this selection. Announcement dates below are different from vehicle model years. A campaign may cover multiple years.
No recall campaigns are recorded in this snapshot.