A vehicle’s cooling fan prevents overheating, which can damage the engine and other essential components in the long run. Some vehicles are equipped with a sensor that detects the cooling fan’s movement while it is running. When your vehicle’s powertrain control module (PCM) detects a fault with the sensor or its circuit, it can trigger the P0526 code.
What Does the P0526 Code Mean?
Diagnostic trouble code (DTC) P0526 stands for “Cooling Fan Speed Sensor Circuit.”
A vehicle’s cooling fan speed sensor monitors the cooling fan’s condition during operation. It monitors if the fan speed recommended by the PCM matches the actual movement of the fan.
The device used to detect fan speed is usually a 3-wire hall effect sensor. It makes use of a 5-volt reference coming from the PCM, a ground wire, and a signal wire to determine fan speed.
Once the PCM detects a fault within the sensor or the wiring, it will trigger the P0526 code.

Note on Fan Clutches
Many vehicles still have viscous fan clutches that enable the fan to spin much slower than the driving pulley. Except that since the early 2000s, these viscous clutches are controlled by the ECM/PCM rather than with the old-fashioned integral bi-metal spring and valve affair used on older viscous fan systems. This kind of control enables the ECM/PCM to precisely control the speed of the cooling fan in a variable fashion rather than simply having one or two speeds.
Many vehicles still have viscous fan clutches that enable the fan to spin much slower than the driving pulley.
– Richard McCuistian, ASE Certified Master Automobile Technician

Note: The definition of code P0526 may be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.
What Are the Common Causes of the P0526 Code?
- Malfunctioning fan clutch or electric fan
- Connection or circuit issues
- Bad cooling fan speed sensor
- Broken accessory belt
- Faulty PCM
What are the Common Symptoms of the P0526 Code?
How to Diagnose the P0526 Code
The P0222 code is a generic powertrain code that can be seen across various vehicles. Although symptoms and causes may be similar, the exact steps to diagnose and fix the issue may vary between vehicles.
If you’re not an experienced DIYer, it’s recommended to bring your vehicle to a professional for an accurate diagnosis. Otherwise, you may go ahead and diagnose the issue yourself.
Learn more about what the proper diagnostic procedure might involve by watching this video:
How to Fix the P0526 Code
Attempting to fix a P0526 code isn’t easy without the right tools and knowledge about cooling fan speed sensor circuits. If you don’t have the time or skills yet to do this on your own, it’s best to leave the job to a mechanic.
However, if you prefer to clear this code yourself, it will be helpful to refer to the appropriate repair manual or an online repair database for vehicle-specific information that can work for your make and model.
Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.