What it means
Cooling fan 1 stays in the activated state when commanded off. The relay or control driver is welded or stuck on.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Cooling Fan 1 is switched by a relay or control driver when the control module requests cooling. This code sets when Fan 1 continues running after it has been commanded off, pointing to a relay stuck closed, a control driver that remains active, or a mechanical obstruction affecting the fan.
Common causes
Most likely first.
- Fan relay contacts welded closed
- Output driver stuck on
- Carbon or debris buildup preventing free movement
Symptoms
- Check-engine light
- Cooling fan runs after the engine is switched off
- Unusual fan noise or increased battery drain
How to diagnose it
- Check freeze-frame data and fan command status to confirm the module was requesting Fan 1 to be off when the fault occurred.
- After shutdown, observe whether Fan 1 continues running and note how long it remains on; keep clear of the blades because the fan can start unexpectedly.
- Inspect Fan 1 for debris or damage that may prevent free movement, and check its wiring and connector for damage or unwanted contact with power.
- Inspect and test the Fan 1 relay for contacts stuck closed, following the manufacturer's procedure.
- If the relay and wiring are sound, check the control driver and command circuit against the manufacturer's specification.
Common fixes
- Remove debris that interferes with Fan 1 movement.
- Repair damaged Fan 1 wiring or connector terminals that keep it powered.
- Replace the Fan 1 relay if its contacts are stuck closed.
- Repair the fan control circuit or replace a failed control driver after confirming the fault.
Can I keep driving?
A brief drive may be possible if engine temperature remains normal, but a fan that keeps running can drain the battery and leave the vehicle unable to start. Avoid leaving it unattended with the fan running, and stop if temperature rises or the fan creates a hazard.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.