P0697: Sensor reference voltage C — circuit/open — what it means, the affected system and what to check before replacing parts.
Meaning, symptoms, causes and checks
The monitor for sensor reference voltage c reports a circuit/open condition; continuity and the exact circuit arrangement need vehicle-specific interpretation. A, B and C label different reference circuits, not fixed lists of sensors across makes. The definition does not mean a traction high-voltage fault.
Affected system: Sensor reference-voltage circuits
Symptoms
- The engine warning lamp may illuminate; other noticeable effects depend on which sensors share the affected reference circuit.
Possible causes
- An open, loose or corroded wire or connector in the sensor reference circuit.
- On configurations where they supply this circuit, a failed fuse, relay or connected sensor may interrupt the reference supply.
What to check
- Record related fault codes and freeze-frame data, then inspect the applicable harness and connectors for disconnection, damage or corrosion.
- Identify reference circuit C from the vehicle wiring diagram; measure its supply and ground against the vehicle procedure before testing or replacing any connected part.
Also written as: P0697-00, P069700, PO697 (some scan tools add the fault-type byte, e.g. -00).