What causes fault code P0495?

• Most likely: Faulty fan clutch (viscous-electronic) or fan control module • Likely: Short to voltage (B+) in the fan control or signal circuit • Possible: Faulty Engine Coolant Temperature (ECT) sensor providing erratic readings • Rare: Internal ECM software fault or CAN bus communication issues with the fan module

How do you fix fault code P0495?

STEP 1: Inspect connectors at the cooling fan and fan clutch for corrosion or backed-out pins. STEP 2: Test the fan control circuit. Measure voltage on the control wire; when commanded 'OFF', it should typically be near 0V or a specific bias voltage. STEP 3: Use a scan tool to perform an 'Active Test'. Command 0% duty cycle and observe if the fan RPM decreases accordingly. STEP 4: Check fan clutch resistance (typically 10-100 Ohms depending on application). If the feedback signal reports high RPM despite low command, replace the fan clutch/module.

Powertrain (Engine & Gearbox)Standard EOBD

P0495 - Fan Speed High

Q: What are the symptoms of fault code P0495?

• Check Engine Light (MIL) illuminated • Cooling fan runs at high speed constantly or is excessively loud • Increased fuel consumption • Reduced engine power (some vehicles enter limp mode if fan control is lost)

Last updated:1 February 2026

Related:Cooling Fan, Fan Clutch, ECT, Engine Control Module (ECM)

System

Powertrain (Engine & Gearbox)

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P0400

Exhaust Gas Recirculation Flow Malfunction

P0401

Exhaust Gas Recirculation (EGR) Flow Insufficient Detected

P0402

Exhaust Gas Recirculation Flow Excessive Detected

P0403

Exhaust Gas Recirculation (EGR) Control Circuit

Technical Description

Diagnostic Trouble Code (DTC) P0495 is set when the Engine Control Module (ECM) detects that the radiator cooling fan speed is higher than commanded. The ECM monitors fan speed via a feedback signal (usually PWM or a Hall-effect sensor) from the fan motor or fan clutch assembly. If the actual RPM exceeds the target RPM by a calibrated threshold (typically >10-20% over a specific duration), the ECM triggers the code. This fault indicates a potential short circuit to voltage in the control circuit or a mechanical failure of the fan clutch electronics.

Possible Causes

Faulty fan clutch (viscous-electronic) or fan control module

Short to voltage (B+) in the fan control or signal circuit

Faulty Engine Coolant Temperature (ECT) sensor providing erratic readings

Internal ECM software fault or CAN bus communication issues with the fan module

Symptoms

Check Engine Light (MIL) illuminated

Cooling fan runs at high speed constantly or is excessively loud

Increased fuel consumption

Reduced engine power (some vehicles enter limp mode if fan control is lost)

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P0495 - Fan Speed High

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P0495 - Fan Speed High

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