GMC SIERRA DENALI · model year

2015 GMC SIERRA DENALI

24 NHTSA complaints, 1 crash report for this specific cohort.

NHTSA overall rating

Not crash-tested

New Car Assessment Program

The 2015GMCSIERRA DENALI carries 24 consumer safety complaints in NHTSA's Office of Defects Investigation database for this specific model-year cohort. Within that volume, owners reported 1 crash, 0 fires, 0 injuries, and 0 fatalities. No NCAP 5-star crash-test rating is available for this model year in the federal database.

Component-level analysis is where model-year complaints become actionable: the top complaint category for the 2015 SIERRA DENALI is service brakes with 7 filings, followed by power train (5) and electrical system (3). Concentration in one or two component groups is the classic signature of a systemic defect; a flat distribution usually reflects normal aging, warranty complaints, or isolated build-plant variability.

NHTSA currently has 2 investigation files overlapping the 2015 SIERRA DENALI. Owners comparing this cohort against neighboring years should pair the counters above with the complaint-by-year trend on the parent model page — a spike in a single year often tracks to a platform refresh, a new transmission supplier, or an updated ECU calibration. Use the related-complaint feed below to read raw owner narratives before deciding whether any pattern here affects your specific use case.

24
Complaints
1
Crashes
0
Fires
0
Injuries
0
Deaths

Total Complaints

24 filings

Crashes Reported

1 reports

Source

NHTSA ODI

Federal complaints database

Complaints vs. fleet median (215)

At or below the fleet median complaint volume.

Complaints by Component

ComponentCount
SERVICE BRAKES7
POWER TRAIN5
ELECTRICAL SYSTEM3
UNKNOWN OR OTHER2
STRUCTURE:BODY:ROOF AND PILLARS1
ENGINE1
AIR BAGS1
STEERING1
SEATS1
ENGINE AND ENGINE COOLING1
FUEL SYSTEM, DIESEL1

Recent Complaints

20251201FUEL SYSTEM, DIESEL

The contact owns a 2015 GMC Sierra 2500 Denali. The contact stated that while driving at 65 MPH, the vehicle lost motive power with the “Engine Power Failure” warning light illuminated. The vehicle was towed to the residence. The vehicle was later towed to an independent mechanic, where it was diagnosed and determined that the fuel system had failed and there were metal shavings in the fuel system. The contact was informed that the fuel system needed to be replaced. The vehicle was not repaired. The dealer was contacted; however, the vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure and referred the contact to the NHTSA Hotline for assistance. The approximate failure mileage was 160,000.

Mileage: 160,000

20250522ENGINE AND ENGINE COOLING

See attached document for complaint.

20240308POWER TRAIN

The contact owns a 2015 GMC Sierra 1500 Denali. 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). Additionally, the failure occurred while slowing down for a traffic signal. The contact stated that the failure was a constant. The contact stated she had not noticed any warning lights during the failure. The contact had taken the vehicle to a local dealer who advised the contact that there were no open recalls for the transmission on the VIN. The vehicle was not diagnosed. The vehicle was not repaired. The manufacturer was not informed of the failure. The failure mileage was unknown.

20201230SERVICE BRAKES

4 MONTHS AGO THE DISPLAY PORTRAYED A MESSAGE STATING, TRAILER BRAKE WARNING, HAVE SYSTEM CHECKED. SINCE THAT TIME I HAVE ATTEMPTED ON NUMEROUS TO HAVE MY VEHICLE CHECKED. BUT AS OF THIS DATE I HAVE NOT BEEN TO HAVE ANY DEALERSHIP LOOK AT MY VEHICLE. I HAVE BEEN TOLD BY DEALERSHIP THAT THE VEHICLE COMPUTER SHOWS A HISTORY BUT NO CURRENT ERROR CODES, AND THEY CAN NOT WORK ON VEHICLE UNTIL IT HAS CURRENT CODES. 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 HAVE NOTICED ON THE INTERNET THAT I AM NOT THE ONLY ONE WITH THIS ISSUE. DANGEROUS SITUATION SHOULD SOMEONE USE VEHICLE TOWING. BIGGEST PROBLEM GM DOES NOT WANT TO EVEN ACKNOWLEDGE THAT THEY HAVE A PROBLEM.

Mileage: 30,000

20200818UNKNOWN OR OTHER

AC BLOWS HOT AIR QONT GOLD FREON FOR LONGER THEN WEEK AND HALF AND IS BACK TO HOT AIR..LEAD TO BELIEVE ITS THE AC CONDENSER HAS FAILED

Mileage: 57,000

20200209SERVICE BRAKES

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 THAT THE BRAKES WHILE THEY WERE HARD TO PRESS WERE PULSATING SO I HAD TO USE EXTREME LEG PRESSURE TO STOP THE VEHICLE. MY TRUCK HAS ALREADY HAD THE RECALL FOR THE SAME ISSUE EARLIER THIS YEAR. WHEN THIS 1ST HAPPENED IT ALMOST CAUSED ME TO WRECK INTO A FENCE

Mileage: 39,500

20191205POWER TRAIN

TRANSMISSION IS NOT ABLE TO BE FIXED. THREE REPAIRS AND GM CAN'T FIX. 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?

Mileage: 3,977

20190226SERVICE BRAKES

HARD BRAKE PEDAL WITH INCREASED EFFORT NEEDED TO DEPRESS THE BRAKE PEDAL. FEELS LIKE TRUCK WILL NOT STOP. HAD TO HAVE TRUCK TOWED. REPORTED BACK ON 11-24-18 TO NHTSA: ( #1115347). BRAKE VACUUM PUMP WAS REPLACED @ GM DEALER ON 11-14-18, SAME SITUATION HAPPENED AGAIN ON 02-19-19. GM TSB # PIT5361D NEEDS TO BE A RECALL.

Mileage: 49,000

20190217POWER TRAIN

WHEN COMING TO A STOP, APPLYING A STEADY AMOUNT OF BRAKE PRESSURE THE TRANSMISSION SHIFTS AND LOSES ALL FORMS OF ENGINE BRAKING CAUSING THE TRUCK TO SPEED UP AND OVERSHOOTS THE STOPSIGN.

Mileage: 55,000

20190107SERVICE BRAKES

POOR BRAKE PERFORMANCE. THE BRAKE PEDAL GETS STIFF AT A LOW SPEED AND CAUSES THE TRUCK TO NOT BRAKE COMPLETELY

Mileage: 77,000

20181211SERVICE BRAKES

FAILURE OF THE BELT DRIVEN VACUUM PUMP WHILE DRIVING CAUSING VERY HARD BRAKING AND ALMOST CAUSED AN ACCIDENT. VACUUM PRESSURE DROPPED OFF AND CAUSED THE PEDAL TO BECOME FIRM. LUCKILY AFTER IT WAS INSPECTED FOR REPAIR THERE WASN'T OIL CONTAMINATION IN THE VACUUM LINE OR BRAKE BOOSTER SO THOSE DID NOT HAVE TO BE REPLACED.

Mileage: 70,135

20181124SERVICE BRAKES

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.

Mileage: 46,000

20181018ELECTRICAL SYSTEM

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.

Mileage: 47,800

20181018POWER TRAIN

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.

Mileage: 47,800

20180804ELECTRICAL SYSTEM

VEHICLE STARTED SHOWING "SERVICE LANE DEPARTURE SYSTEM, SERVICE PARK ASSIST, SERVICE TRAILER BRAKE SYSTEM" ALARMS WHILE DRIVING. UPON TAKING IT TO THE DEALER FOR SERVICE IT WAS FOUND TO HAVE BROKEN WIRING FOR HAPTIC MOTOR FOR DRIVERS SEAT. NOT ONLY DID THIS CAUSE A POSSIBLE SAFETY ISSUE WITH THE LANE DEPARTURE SYSTEM AND TRAILER BRAKE SYSTEM NOT WORKING CORRECTLY, BUT IT ALSO CAUSED A POSSIBLE FIRE CONCERN DUE TO BROKEN WIRING.

Mileage: 22,567

20180804SEATS

VEHICLE STARTED SHOWING "SERVICE LANE DEPARTURE SYSTEM, SERVICE PARK ASSIST, SERVICE TRAILER BRAKE SYSTEM" ALARMS WHILE DRIVING. UPON TAKING IT TO THE DEALER FOR SERVICE IT WAS FOUND TO HAVE BROKEN WIRING FOR HAPTIC MOTOR FOR DRIVERS SEAT. NOT ONLY DID THIS CAUSE A POSSIBLE SAFETY ISSUE WITH THE LANE DEPARTURE SYSTEM AND TRAILER BRAKE SYSTEM NOT WORKING CORRECTLY, BUT IT ALSO CAUSED A POSSIBLE FIRE CONCERN DUE TO BROKEN WIRING.

Mileage: 22,567

20180525POWER TRAIN

STARTING THE VEHICLE I'M PUTTING THE TRUCK IN REVERSE, THE TRUCK LUNGES BACKWARDS. ALSO A VIOLENT JERK OF THE VEHICLE HAPPENS. THIS HAPPENS A MAJORITY OF THE TIME. PUTTING THE VEHICLE INTO GEAR TO DRIVE I HAVE A VIOLENT JERK AND A LOUD NOISE. THE TRUCK DOES NOT LUNGE FORWARD WHEN PLACING THE TRUCK INTO DRIVE. THIS HAPPENS A COUPLE OF TIMES A DAY. THIS IS NOT AN ISOLATED INCIDENT.

Mileage: 55,000

20180204SERVICE BRAKES

HARD BRAKE PEDAL. AT LOW SPEED THE BRAKE PEDAL GETS REALLY HARD AND MAKES IT HARD TO STOP THE TRUCK. PEDAL HAS TO GET PUSHED REALLY HARD TO BARELY STOP FROM HITTING OTHER VEHICLES. ONGOING ISSUE.

Mileage: 56,000

20171220STEERING

TL* THE CONTACT OWNS A 2015 GMC SIERRA DENALI. WHILE DRIVING APPROXIMATELY 60 MPH, THE STEERING LOST POWER AND THE POWER STEERING WARNING INDICATOR ILLUMINATED. THE VEHICLE WAS TOWED TO THE DEALER (SEWELL BUICK GMC OF DALLAS IN DALLAS, TX, PHONE NUMBER: 214-350-8000) WHERE A DIAGNOSTIC TEST WAS PERFORMED. THE CONTACT WAS NOT GIVEN THE RESULTS OF THE TEST. THE VEHICLE WAS NOT REPAIRED. THE MANUFACTURER WAS MADE AWARE OF THE FAILURE AND OFFERED TO PAY A PERCENTAGE OF THE REPAIR COSTS. THE FAILURE MILEAGE WAS 39,900. *BF UPDATED 8/28/18*JB

Mileage: 39,900

20171016AIR BAGS

2015 GMC SIERRA. CONSUMER WRITES IN REGARDS TO SENSING AND DIAGNOSTIC MODULE SAFETY RECALL. *LD THE CONSUMER REQUESTED TO BE ADVISED OF THE OPTIONS OF HAVING A RECALL COMPLETED ON AN ISLAND. UPDATED 10/16/2017*JS

Compare 2015GMCSIERRA DENALI to Similar Vehicles

NHTSA Investigations

Frequently Asked Questions

How many complaints does the 2015 GMC SIERRA DENALI have?
The 2015 GMC SIERRA DENALI has 24 NHTSA complaints, 1 crashes, 0 fires, 0 injuries, and 0 deaths reported.
What are the most common problems with the 2015 GMC SIERRA DENALI?
The most-complained component for the 2015 GMC SIERRA DENALI is SERVICE BRAKES with 7 complaints. Other frequently reported areas include POWER TRAIN and ELECTRICAL SYSTEM.
Is the 2015 GMC SIERRA DENALI safe to buy?
Review the complaint history, crash and fire reports, safety ratings, and recall status on this page to make an informed decision. No NHTSA crash test rating is available for this model year. Compare with other model years using the links above.
Where does this data come from?
All complaint, recall, and safety rating data is sourced from the National Highway Traffic Safety Administration (NHTSA). Complaints are filed by vehicle owners through NHTSA's Office of Defects Investigation.

Vehicle Safety Guides

Data as of 2025. Sources: NHTSA Office of Defects Investigation (ODI) complaints database, NHTSA recall campaign API, NHTSA NCAP crash-test ratings, and NHTSA FARS for fatality cross-reference.