P0694Fan 2 Control Circuit High
The control circuit for cooling fan 2 is reading higher voltage than expected, typically from an open circuit, failed relay, or short to battery voltage.
Definition
The PCM operates cooling fan 2 through a dedicated relay or driver stage and expects the control line to be pulled low when commanded on. P0694 sets when the circuit remains high in a state where it should be low — an open control wire, an open relay coil, or a short to power. Because fan 2 usually provides high-speed or A/C-assist cooling, the engine may overheat when working hard or A/C performance may suffer, and the MIL will illuminate.
Common causes
- Open in the fan 2 control wiring or a backed-out connector terminal
- Open fan 2 relay coil
- Control wire shorted to battery voltage
- Corroded relay socket in the underhood fuse box
- Failed fan control module
- Faulty PCM driver
Common misdiagnoses
- Fan motor replaced when the control side of the circuit is open
- Coolant temperature sensor replaced for an overheat that traces to the dead fan
- A/C system serviced for pressure complaints caused by lost fan 2 airflow
Troubleshooting steps
1.Command fan 2 on with a scan tool
Confirm the fan does not respond and that the code sets with the output active.
2.Check control-wire continuity
Measure from the PCM connector to the relay socket — expect under about 1 ohm; an open means a broken wire or terminal fretting.
3.Test the relay and socket
Verify coil resistance and inspect the socket for corrosion or spread terminals; swap with an identical relay to confirm.
4.Check for short to voltage
If the control line shows battery voltage even with the relay removed and output commanded on, trace the harness for contact with a power feed.
5.Confirm the fan motor works
Power the fan directly at its connector to prove the motor before replacing control-side parts.