The P0526 code indicates that the engine control module (ECM) has detected a malfunction in the cooling fan speed sensor circuit. This typically means the signal from the sensor is missing, erratic, or outside the expected voltage range.
The internal circuitry of the speed sensor has failed, providing an incorrect or nonexistent signal to the ECM.
Corroded, frayed, or broken wires in the sensor circuit are interrupting the signal transmission.
An internal failure within the fan motor assembly that houses the speed sensor.
Moisture or debris in the electrical connectors causing high resistance or an open circuit.
A malfunction in the engine computer's processing of the sensor signal, though this is rare.
Yes. In many vehicles, the fan will enter a 'fail-safe' mode and run at maximum speed to prevent overheating even if the speed sensor is not functioning.
No. It is highly uncommon for the PCM to be the cause of this code; the issue is almost always located in the sensor, the motor, or the wiring.
Potentially. If the PCM cannot verify the fan speed, it may fail to activate the fan at the correct time, or the fan motor itself may have failed along with the sensor.