P0495 means the Powertrain Control Module (PCM) has detected that the speed signal from the primary engine cooling fan (Fan 1) is above the expected threshold, indicating an overspeed condition. This usually points to a problem with the fan speed sensor, its wiring, or the fan motor itself, rather than an actual mechanical overspeed.
The Hall‑effect or optical sensor that reports fan speed to the PCM may be shorted, open, or sending an erratic high‑frequency signal.
Damaged, corroded, or loosely connected wires between the sensor and PCM can cause a false high‑speed reading (e.g., short to power or open circuit).
A shorted winding or internal short in the fan motor can draw excess current, making the sensor interpret the motor as running faster than commanded.
If the vehicle uses a separate fan control module, a failure in that module can cause it to drive the fan at an excessive speed.
Although rare, a corrupted PCM output or internal fault could misinterpret the sensor signal; this is considered only after other causes are ruled out.
No. The PCM is rarely the cause of this code. Most P0495 issues stem from the fan speed sensor, its wiring, or the fan motor. Replace the PCM only after all other components have been tested and found functional.
A blocked radiator can cause overheating, but it does not directly trigger an overspeed fan code. The code relates to the fan speed signal, not airflow restriction.
Driving is possible for short distances, but the cooling system may not regulate temperature properly, risking overheating. Address the issue promptly to avoid engine damage.