The cooling fan control circuit is reading low. If the fan will not run, the engine will overheat in traffic even though it is fine on the move.
P0691 — also written PO691, P 0691, 0691 — is the OBD-II code for fan 1 control circuit low. Same code, same fix: this page covers every spelling of it.
P0691 is a electrical fault code, typically costing £120–£650 to put right in a UK garage.
What causes P0691?
- Failed fan control module or resistor pack
- Seized fan motor
- Blown high-current fuse
- Corroded connector
How P0691 is fixed
- Run the fan on command with a scan tool
- Replace the fan module or motor
- Repair the fuse box terminal
P0691 repair cost in the UK
Most P0691 repairs land between £120–£650 including parts and labour. The spread is wide because the cheap fix (a sensor, a hose, a leak) and the expensive fix (a major component) throw the same code — which is why a proper diagnosis before parts are bought saves the most money.
Can you drive with P0691?
Not in traffic. Watch the temperature gauge closely and pull over if it climbs.
Urgency: high.