Radiator cooling fan circuit

What it means

The electric fan pulls air through the radiator when the car is slow or stopped. The computer switches it through relays or a control module. These codes mean a fan is not responding to the command.

Codes in this group

Bank 1 is the side of the engine that has cylinder 1. Sensor 1 is before the catalytic converter and sensor 2 is after it. More terms explained.

What you may notice

• Engine temperature climbing in traffic but normal on the open road
• Air conditioning turning warm when stopped
• Fan never running, or running all the time

Common causes

Most likely first:

• A failed fan relay or blown fuse
• A worn-out fan motor
• A failed fan control module
• Damaged wiring or a corroded plug

What to check first

• Watch the temperature gauge closely in slow traffic
• Check the fan fuses and relays in the owner's manual
• If the gauge heads towards red, stop and switch off before the engine overheats

Have a mechanic confirm. A fault code tells you which system reported a problem, not which part has failed. The same code can have several causes, and they differ between car models. Use this page to understand the code, then have a qualified mechanic test the car before any part is replaced.

After the repair

Once the cause is fixed, the code can be cleared with a scan tool, or the warning light goes out by itself after several trips without the fault. Clearing a code without fixing the cause only hides it for a while. More about clearing codes.

Related codes

Engine overheating or overspeed (P0217), Fuel level sensor (P0460), Vehicle speed sensor (P0500), Idle speed control (P0505), Brake pedal switch (P0504), Engine oil pressure sensor (P0520), Air conditioning pressure sensor (P0530), Battery and charging voltage (P0560). All codes.

Written in November 2026. These are generic OBD-II codes, the same on all makes. Causes and repair steps differ between models.