P0527 Fan Speed Sensor Circuit Range/Performance Trouble Code

P0527 Fan Speed Sensor Circuit Range/Performance

OBD-II Trouble Code Technical Description

Fan Speed Sensor Circuit Range/Performance

This diagnostic trouble code (DTC) is a generic OBD-II powertrain code. It is considered generic because it applies to all makes and models of vehicles (1996-newer), although specific repair steps may vary depending on the model.

What does that mean?

Some vehicles are equipped with a sensor at the end of the cooling fan that detects movement during vehicle operation. The sensor is used to determine if the fan is running on a fan clutch equipped vehicle, or used to verify fan speed commanded by the Powertrain Control Module (PCM) or Engine Control Module (ECM) matches the actual fan speed detected on an electric fan equipped vehicle.

 

The sensor used is a 3 wire, hall effect sensor which uses a 5 volt reference source from the PCM, a ground wire and a signal wire to the PCM to determine fan speed. For a P0527 to be triggered, the PCM/ECM has determined the actual fan speed does not match the desired or commanded speed.

Note: Be careful not to touch an electric fan as it may turn on even when the vehicle is not operating. This code is similar to P0526, P0528 and P0529

Symptoms

Symptoms of a P0527 DTC may include:

Malfunction Indicator Lamp illumination (a.k.a. Check Engine Light) Vehicle may be overheating or running hotter than normal

Causes

Potential causes of a P0527 code include:

Fan clutch or electric fan is not operating at desired or commanded speed

Possible Solutions

Fan clutch equipped - Visually verify the fan is spinning while the engine is operating. If the fan is spinning very slowly on a cold start, replace the fan clutch assembly. It may be necessary to use an advanced scan tool to see the actual fan speed in relation to the desired fan speed.

Electrical fan equipped - Visually verify the fan is turning on and off when the PCM/ECM commands the fan to operate when the engine reaches certain temperatures. The fan may be automatically turned on when the air conditioner is turned on. Some fans may be turned on using an on/off relay or activated by Pulse Width Modulation (PWM) with variable speed fans.

It may be necessary to use an advanced scan tool to see the actual fan speed in relation to the commanded fan speed. If the fan speed is lower than specification, replace electrical fan assembly or fan motor.

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