"How reliable is the 2015 Gmc Sierra Denali?"

"Based on 24 NHTSA complaints, the 2015 Gmc Sierra Denali has a median complaint mileage of 47800 miles. The most common issue is SERVICE BRAKES."

"What are common problems with the 2015 Gmc Sierra Denali?"

"The most frequently reported component in NHTSA complaints for the 2015 Gmc Sierra Denali is SERVICE BRAKES, accounting for a significant portion of the 24 total complaints filed."

2015 Gmc Sierra Denali: Reliability Data

Source: NHTSA — 24 complaints

Total Complaints

47,800mi

Median Mileage

SERVICE BRAKES

Top Issue

Crash Reports

When Do Complaints Happen?

Distribution of NHTSA complaints by vehicle mileage at time of report.

30,000 25th Percentile

47,800 Median Mileage

55,000 75th Percentile

What Fails?

Most reported component issues from NHTSA complaints.

SERVICE BRAKES

POWER TRAIN

ELECTRICAL SYSTEM

UNKNOWN OR OTHER

STRUCTURE:BODY:ROOF AND PILLARS

ENGINE

AIR BAGS

STEERING

SEATS

ENGINE AND ENGINE COOLING

Severity Assessment

Crashes

Fires

Injuries

Deaths

Sample Complaint Reports

"TL* THE CONTACT OWNS A 2015 GMC SIERRA DENALI. WHILE OPERATING THE VEHICLE, RAIN WATER FROM THE ROOF MOUNTED ANTENNA LEAKED INTO THE PASSENGER SIDE CABIN. THE CONTACT INDICATED THAT THE WATER CAUSED THE ELECTRONICS IN THE VEHICLE TO MALFUNCTION, SUCH AS THE ONSTAR AND NAVIGATION SYSTEM. THE VEHICLE ..."

"BAD WELD ON HVAC CONDENSER. WAITING 7+ WEEKS FOR NATIONAL BACK-ORDERED REPLACEMENT PART. WHY IS THERE NO RECALL SINCE CLEARLY THIS IS A MAJOR SPILL?"

"MY GMC 2015 DIESEL DURIMAX TRUCK HAD THE ENGINE LIGHT TURN ON AND SAID EMISSION NEEDS SERVICED. IT PROCEEDED TO CUT MY TRAVELING SPEED FROM 75 MPH TO 65 MPH TO 55 MPH. I MADE IT TO DENVER COLORADO BARELY WITHOUT THE TRUCK FALLING TO 4 MPH. I WENT YESTERDAY TO HAVE IT SERVICED. THEY SAID THAT THEY FI..."

Source: NHTSA ODI Complaints Database. Names and identifying details omitted.

Data source: View this vehicle on NHTSA.gov | NHTSA ODI Complaints Database. Public domain.

Methodology: Complaint counts and mileage distributions are computed directly from consumer-reported NHTSA complaints. This data represents reported issues, not failure rates — vehicles without complaints are not represented. Full methodology.

Data through: 2026-03-28