What breaks most · 1999 to 2015 model years
GMC Denali problems by year
Owners have filed 171 safety complaints with NHTSA about the GMC Denali across model years 1999 to 2015. Three years stand out: 2003 for electrical system complaints, 2002 for engine and cooling complaints and 2001 for powertrain and transmission complaints. The quietest years are 2009, 2007 and 2008.
- Years to check closely: 2003, 2002, 2001
- Fewest complaints: 2009, 2007, 2008
- Complaints on file
- 1711999 to 2015, all trims
- Worst year
- 200332 complaints
- Crashes reported
- 122 fires · 8 injuries · 0 deaths
- Typical failure mileage
- 64kMedian where owners gave mileage
- Recall campaigns
- 4Across the years shown
Complaints by model year
Raw filings with NHTSA, not adjusted for how many were sold.
| Model year | Complaints | Crashes | Recalls | Most-reported component |
|---|---|---|---|---|
| 14 | 0 | 1 | Brakes (hydraulic) (5) | |
| 21 | 3 | 1 | Brakes (hydraulic) (6) | |
| 22 | 2 | 1 | Powertrain and transmission (5) | |
| 23 | 3 | 1 | Engine and cooling (6) | |
| 32 | 3 | 0 | Electrical system (6) | |
| 3 | 0 | 0 | Air bags (1) | |
| 4 | 0 | 0 | Air bags (4) | |
| 2 | 0 | 0 | Air bags (1) | |
| 5 | 0 | 0 | Unknown or other (4) | |
| 11 | 0 | 0 | Unknown or other (8) | |
| 6 | 0 | 0 | Unknown or other (3) | |
| 5 | 0 | 0 | Unknown or other (3) | |
| 5 | 0 | 0 | Brakes (1) | |
| 18 | 1 | 0 | Exterior lighting (6) |
What fails on the 2003 GMC Denali
| Component | Share of complaints | Filings | Crashes | Parts for this job |
|---|---|---|---|---|
| Electrical systemAlternators, starters and ignition | 19% |
6 | 0 | Shop all electrical system parts, not filtered to this vehicle |
| SteeringPower steering pumps, racks and hoses | 16% |
5 | 2 | Shop all steering parts, not filtered to this vehicle |
| Speed control and throttleThrottle and pedal sensors | 16% |
5 | 0 | Shop all speed control and throttle parts, not filtered to this vehicle |
| Powertrain and transmissionTransmission parts | 9% |
3 | 1 | Shop all powertrain and transmission parts, not filtered to this vehicle |
| Brakes (hydraulic)Brake pads, rotors and calipers | 9% |
3 | 0 | Shop all brakes (hydraulic) parts, not filtered to this vehicle |
| Stability controlABS and wheel speed sensors | 6% |
2 | 0 | Shop all stability control parts, not filtered to this vehicle |
| Engine and coolingRadiators, thermostats and cooling | 6% |
2 | 0 | Shop all engine and cooling parts, not filtered to this vehicle |
| Exterior lightingHeadlights, tail lights and bulbs | 6% |
2 | 0 | Shop all exterior lighting parts, not filtered to this vehicle |
One complaint can name more than one component, so shares add to more than 100%. "Unknown or other" is NHTSA's uncategorized bucket and is shown but never ranked.
In owners' words
Complaint narratives as filed with NHTSA, trimmed for length.
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The speedometer shows inaccurate and erratic readings. Speed appears to be 20 mph off and will jump to different speeds. No specific event caused this to happen, it just started about a month ago and has progressively gotten worse over time.
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Consumer called complaining about having problems with engine overheating. Dealer was contacted, and stated that it was normal. This has occurred over five times. Overheating up to over the red sign of overheating. Manufacturer was contacted, and stated that they won't do anything.*ak
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Vehicle idles then cuts off, especially on a turn or a incline. I have to small children and the vehicle will cut off in the middle of traffic. Last night i thought i was going to be in major car accident. *la
How to read this page
Every figure comes from the National Highway Traffic Safety Administration's public complaint database, which holds every safety-related defect complaint filed by owners since 1995. We refresh it monthly and count each complaint once per component it names. Data through September 6, 2026.
NHTSA only accepts safety-related complaints. Rattles, paint, infotainment bugs and other annoyances are under-reported here, so this page is a map of what fails in ways owners consider dangerous, not a full reliability score.
Counts are raw. Use the year-over-year shape and the component mix, not the absolute numbers. Where a component maps to parts we stock, the row links to that category filtered to the year you are viewing. Air bag and seat belt complaints link to the recall checker instead, because those repairs are almost always covered.
Common questions
Which GMC Denali years have the most problems?
By NHTSA complaint volume, 2003, 2002, 2001 carry the most filings on the GMC Denali. The 2003 alone has 32 complaints, led by electrical system.
What is the most common GMC Denali problem?
On the 2003 model year, the most-reported component is electrical system with 6 complaints. The table above lists the top components for every year.
At what mileage do GMC Denali problems start?
The median mileage at failure across all GMC Denali complaints that include mileage is about 64,000 miles. Older model years skew higher; the per-year figure is in the "at a glance" card.
Are these complaints verified?
No. NHTSA publishes complaints as submitted and does not investigate individual filings. Patterns across hundreds of complaints are meaningful; a single one is not.