P0527 OBD-II Trouble Code: Fan Speed Sensor Circuit Range or Performance Issue

Diagnostic Trouble Code (DTC): P0527

P0527 code definition

The P0527 diagnostic trouble code is an indication that there is a range or performance issue with the fan speed sensor circuit.

Related Trouble Codes:

• P0526 OBD-II Trouble Code: Fan Speed Sensor Circuit
• P0528 OBD-II Trouble Code: Fan Speed Sensor Circuit No Signal
• P0529 OBD-II Trouble Code: Fan Speed Sensor Circuit Intermittent

What the P0527 code means

Cooling fans are used to cool the engine temperature and the A/C system, and are controlled by the Powertrain Control Module (PCM). Fan speed sensors are used in vehicles for two purposes. Vehicles with a fan clutch use the fan speed sensor to make sure the fan is running. Vehicles with an electric fan use the fan speed sensor to ensure the fan speed coincides with the fan speed that the Powertrain Control Module (PCM) requires. The Powertrain Control Module (PCM) sets the required fan speed. If the PCM receives a signal from the fan speed sensor indicating a fan speed that does not coincide with the required speed, the P0527 diagnostic trouble code will be stored and the check engine light will come on.

What causes the P0527 code?

• Faulty engine coolant temperature sensor
• Engine coolant temperature sensor wires that are frayed, broken, or shorted
• Engine coolant temperature sensor connectors that are damaged, loose, or corroded
• Faulty cooling fan motor
• Faulty cooling fan relay
• Faulty fan clutch
• Faulty electric fan
• Blown fuse
• Faulty fan speed sensor
• Fan speed sensor wires that are frayed, broken, or shorted
• Fan speed sensor connectors that are damaged, loose, or corroded

What are the symptoms of the P0527 code?

• Check Engine Light is on
• Car is overheating
• A/C is not working

How does a mechanic diagnose the P0527 code?

• Diagnostic trouble codes should be diagnosed in the order that they appear in the powertrain control module (PCM).
• Use an OBD-II scanner to collect all trouble codes that have been stored by the powertrain control module (PCM) as well as freeze frame data.
• Inspect the cooling fan assembly wires for frays, breaks, and shorts. Repair and replace as necessary.
• Inspect the cooling fan assembly connectors for damage, corrosion, and bent pins. Repair and replace as necessary.
• Check the cooling fan assembly motor for proper operation and power supply. Replace as necessary.
• Inspect the fan motor relay and fuses. Repair and replace as necessary.
• Clear all diagnostic trouble codes from Powertrain Control Module (PCM) and operate the vehicle to see if the P0527 diagnostic trouble code comes back.
• If the P0527 trouble codes come back, inspect the engine coolant temperature sensor for frays, breaks, and shorts. Repair and replace as necessary.
• Inspect the engine coolant temperature sensor connector for damage, corrosion, and bent pins. Repair and replace as necessary.
• Clear all diagnostic trouble codes from Powertrain Control Module (PCM) and operate the vehicle to see if the P0527 diagnostic trouble code comes back.
• If the P0527 trouble code comes back and the vehicle is equipped with a high or low pressure switch for the A/C or fan, this will need to be checked for proper operation. Replace as necessary.
• Clear all diagnostic trouble codes from Powertrain Control Module (PCM) and operate the vehicle to see if the P0527 diagnostic trouble code comes back.
• If the P0527 trouble code comes back, inspect the Powertrain Control Module (PCM) wiring and ensure it is working properly. It is rare for this Powertrain Control Module (PCM) to fail but it is possible.

Common mistakes when diagnosing the P0527 code

The most common mistake made when diagnosing the P0527 trouble code is replacing the cooling fan assembly when the problem is a fault relay, damaged wiring, a bad fuse, or damaged wiring. It is important to inspect all components before replacing the cooling fan assembly.

How serious is the P0527 code?

A diagnostic trouble code is normally considered serious when it causes driveability issues or a change in performance. The P0527 diagnostic trouble code causes driveability issues and is considered very serious if the car is overheating. This should be diagnosed and repaired in a timely manner.

What repairs can fix the P0527 code?

• Replace faulty engine coolant temperature sensor
• Repair or replace engine coolant temperature sensor wires that are frayed, broken, or shorted
• Repair or replace engine coolant temperature sensor connectors that are damaged, loose, or corroded
• Replace faulty cooling fan motor
• Replace faulty cooling fan relay
• Replace faulty fan clutch
• Replace faulty electric fan
• Replace blown fuse
• Replace faulty fan speed sensor
• Repair or replace fan speed sensor wires that are frayed, broken, or shorted
• Repair or replace fan speed sensor connectors that are damaged, loose, or corroded

Additional comments for consideration regarding the P0527 code

Always complete a thorough inspection of the sensors, fuses, and wiring first. These components are often missed or overlooked during the diagnosis process and leads to multiple failures and the P0527 diagnostic trouble code returning.

Need help with a P0527 code?

YourMechanic offers certified mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.