P0495 low

Fan Speed High - Bank 1

The P0495 code means the vehicle's onboard diagnostic system has detected: Fan Speed High - Bank 1. This is a low severity code.

My Garage →

Keep driving?: Yes, but fix soon
DIY difficulty: moderate
Estimated cost: $100 - $400 (parts and labor)

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Common Symptoms

Check Engine Light on
Cooling fan excessively loud
Fan runs at high speed unnecessarily
Possible overcooling

Probable Causes (Ranked by Likelihood)

Fan control module stuck in high-speed output Very High
Fan relay welded closed High
Coolant temperature sensor reading higher than actual temperature Moderate
Shorted wiring in fan speed control circuit Moderate

Step-by-Step Diagnostic Procedure

Compare coolant temperature sensor reading to actual coolant temperature; if sensor reads high, replace it
Test the fan relay by removing it and checking if the fan stops; a welded relay will keep the fan running
Inspect the fan control module for signs of overheating or water damage
Use a scan tool to command different fan speeds and verify the system responds to lower speed commands

Frequently Asked Questions

Why is my cooling fan so loud with P0495?

P0495 indicates the fan is running at high speed when it should not be. The fan control system is unable to reduce fan speed to match cooling demand, so it runs at maximum speed creating excessive noise.

Can a stuck fan relay cause P0495?

Yes. A relay with welded contacts will keep the fan circuit energized at high speed regardless of ECM commands. Removing the relay will confirm this diagnosis if the fan stops.

Will P0495 affect fuel economy?

Yes, slightly. A constantly running high-speed fan places additional load on the electrical system, which increases alternator load and parasitic drag on the engine, reducing fuel economy.