AI Damage2015 GMC Sierra Denali: common problems
Owners of the 2015 GMC Sierra Denali filed 22 complaints with NHTSA, most often about service brakes and powertrain. Details by component below, with sources.
Key figures
- Owner complaints
- 22
- involving a crash
- 1
What fails most often
- 1 Service brakes 32% of all complaints
- 2 Powertrain 23% of all complaints
- 3 Electrical system 14% of all complaints
- 4 Air bags 5% of all complaints
- 5 Engine 5% of all complaints
- 6 Engine and cooling 5% of all complaints
- 7 Fuel system 5% of all complaints
- 8 Seats 5% of all complaints
- Service brakes: 7 complaints (32% of all).
- Powertrain: 5 complaints (23% of all).
- Electrical system: 3 complaints (14% of all), 1 of them with a crash reported by the owner.
- Air bags: 1 complaints (5% of all).
- Engine: 1 complaints (5% of all).
Symptoms owners describe
How many of the 22 NHTSA complaints mention each symptom (automatic count from complaint text; one complaint can mention several).
Components owners complain about
| Component | Owner complaints | involving a crash | Technical service bulletins (TSB) |
|---|---|---|---|
| Service brakes | 7 | 0 | 0 |
| Powertrain | 5 | 0 | 0 |
| Electrical system | 3 | 1 | 0 |
| Air bags | 1 | 0 | 0 |
| Engine | 1 | 0 | 0 |
| Engine and cooling | 1 | 0 | 0 |
| Fuel system | 1 | 0 | 0 |
| Seats | 1 | 0 | 0 |
| Steering | 1 | 0 | 0 |
| Structure | 1 | 0 | 0 |
| Other | 2 | 0 | 0 |
What owners report
Short excerpts of NHTSA complaints in the original wording. These are owner statements not verified by NHTSA; personal data removed.
The contact also stated that the electrical failure also caused a crash on the road median because the steering wheel locked. There were no injuries and a police report was not filed. The vehicle was taken back to the dealer for further inspection. The manufacturer was notified. The vin was not available.
The contact stated that while driving at 65 MPH, the vehicle lost motive power with the âEngine Power Failureâ warning light illuminated. The vehicle was towed to the residence.
The contact stated that while shifting the vehicle from park(P) to drive(D), the vehicle hesitated and then jerked into gear. The contact stated that the entire vehicle was shaking when it jerked into gear. The contact stated that the failure was also occurred while shifting the vehicle into reverse(R).
So I have a truck that is designed to tow cargo/vehicle but I am not able to use my truck for that purpose because of this warning message. I have contacted dealerships, customer service with gmc and even filed a complaint with tennessee dept of consumer affairs, but no one wants to help with my problem.
I was backing up at very low speed the brake pedal got very hard and the vehicle acted like it did not want to stop I had to keep pushing extremely hard on to the break to get the vehicle to stop I tried it again in drive and the vehicle did this exact same thing this time I noticed after paying particular attention…
Transmission jerks, slips, clunks. Uncomforable to drive. I am stuck with subpar vehicle. Gm has been horrible to work with. 17 recalls? Why cant gm make a solid reliable vehicle after 100 years in business?
Power brake vacuum pump issue. Lost brakes while driving in stop and go city traffic. Had to have truck towed, was unsafe to drive due to no brakes.
Interior dash lights goes out and a few minutes later the engine cuts off while I'm trying to park. Each time while I was backing into my parking space. After sitting for about 30 seconds the lights dash board lights come back on, then I restart the truck. Sometimes while driving the dash board light blink of and on.
When owners complained
NHTSA complaints by filing year. The peak shows at what age the problems show up most.
Comparison
By complaint count this model year ranks 7,906 of 36,659 model years in the NHTSA data (top 22% most complained about).
On average one model year of the Sierra Denali has 14 complaints (18 years in the data). This year has 22, above average.
What to check before buying
- Service brakes. Pedal feel, ABS operation, leaks, discs and hoses.
- Powertrain. Shift quality under load, harsh shifts, transmission codes, CV joints.
- Electrical system. Scan all modules, test the battery and alternator, inspect connectors near the impact zone.
- Air bags. Check the SRS light, stored codes and airbag/curtain status after any impact.
Other years of this model
- Sierra Denali 200213 sources
- Sierra Denali 200411 sources
- Sierra Denali 20054 sources
- Sierra Denali 20065 sources
- Sierra Denali 200818 sources
- Sierra Denali 20097 sources
- Sierra Denali 201010 sources
- Sierra Denali 201128 sources
- Sierra Denali 201210 sources
- Sierra Denali 20138 sources
- Sierra Denali 201414 sources
- Sierra Denali 2016896 sources
- Sierra Denali 2017585 sources
- Sierra Denali 2018609 sources
- Sierra Denali 2019587 sources
- Sierra Denali 2020369 sources
Questions and answers
What are the most common problems with the 2015 GMC Sierra Denali?
Owner complaints to NHTSA most often mention: service brakes, powertrain, electrical system. Total complaints: 22. The most frequent symptoms in complaint texts: warning lights, check engine (18%), jerking, harsh shifts (14%), loss of power / limp mode (9%).
How many service bulletins (TSB) were issued for the 2015 GMC Sierra Denali?
NHTSA lists 0 manufacturer service bulletins for this year. A bulletin tells dealers how to diagnose or fix a known issue; it is not a recall.
Should I buy a 2015 GMC Sierra Denali from a US auction?
Owner complaints describe defects, not crash damage. Before bidding, check the components listed above and review the lot photos: VinWind builds a report of visible and hidden damage by VIN.
Other 2015 models
Read also
Sources: public NHTSA data (USA): service bulletins and owner complaints; YouTube: links to videos credited to their authors. Complaints are owner statements not verified by NHTSA, and describe defects rather than crash damage. Data updated 2026-11-06.