P0495 on GMC: How to Diagnose & Fix
Fan Speed High
1 GMC model · 1 documented issue · 1 critical · $200-$500 repair
P0495 on GMC by model: symptoms, diagnosis and fix
The electronically controlled fan clutch fails, causing overheating in traffic or at low speeds. The Envoy uses a clutch-type fan rather than electric fans, and the electronic control module in the clutch is the weak point.
Common Symptoms
- Overheating in traffic
- Temperature gauge climbs at idle
- Fan runs at full speed constantly
- A/C performance poor at idle
How to Fix
Replace fan clutch assembly (Hayden 3262). Some owners upgrade to a dual electric fan conversion for more reliable cooling. Ensure coolant system is flushed and thermostat is functioning properly.
Sources for this issue (1)
P0495 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0495 mean on a GMC?
P0495 stands for "Fan Speed High." This code indicates the engine computer (PCM) has detected that the cooling fan is running faster than commanded, or at high speed when it should not be. The PCM monitors the cooling fan's operation and compares actual fan speed or current draw against expected values. While it usually does not leave you stranded, a fan stuck running high can drain the battery and points to an electrical control fault in the cooling system. On GMC it is documented across 1 model: Envoy.
What are the most common causes of P0495?
The most common causes of P0495 are: Faulty cooling fan relay stuck closed, Short to power in the fan control circuit, Failed fan control module or PCM driver, Damaged or corroded wiring/connectors at the fan, Faulty cooling fan motor, Engine coolant temperature sensor sending false high readings. The specific cause varies by vehicle.
How much does it cost to fix P0495 on a GMC?
Published repair estimates on GMC range from $200 to $500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0495 on a different make?
View P0495 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.