Symptoms of P0694
- Check-engine light, sometimes with several unrelated codes at once.
- Warning lights, a no-start, or intermittent electrical faults.
- Communication or module-reset problems on a scan tool.
Common causes of P0694
- Low battery voltage, poor grounds, corroded connectors, or blown fuses.
- Wiring or network (CAN bus) faults between modules.
- A module software/programming issue, or rarely a failed controller.
Useful checks before replacing parts
- Review fan 2 command, feedback voltage, relay state, coolant temperature, A/C request, charging voltage, freeze-frame data, and related fan codes.
- Inspect for short-to-voltage faults, stuck relays, open grounds, melted fan connectors, damaged harness insulation, and backfeed through fan module circuits.
- Verify whether fan 2 stays powered when not commanded and whether relay removal changes the high signal.
Related OBD-II codes
These nearby computer entries can help compare wording and pin down the fault area.