The P0697 trouble code indicates that the Engine Control Module (ECM) or Powertrain Control Module (PCM) has detected an open circuit in the sensor reference voltage “C” circuit. Sensor reference voltage “C” is a specific voltage signal used by various sensors in the vehicle’s engine management system to provide crucial data to the ECM or PCM for engine operation. When the ECM or PCM detects an open circuit in this voltage circuit, it triggers the P0697 code.
P0697 Sensor Reference Voltage “C” Circuit Open
Code symptoms P0697.
1. Check Engine Light (CEL) illuminated on the dashboard.
2. Engine may run in a reduced power or “limp” mode to prevent potential damage.
3. Decreased fuel efficiency.
4. Engine hesitation or stalling.
5. Vehicle may fail to start or have difficulty starting.
This code is common in brands such as:: Chevrolet, Renault, Ford, Toyota, Nissan, Mercedes Benz, Honda.
Causes of the code P0697.
1. Open or broken wiring in the sensor reference voltage “C” circuit.
2. Loose or corroded electrical connections in the sensor reference voltage circuit.
3. Faulty sensor requiring sensor reference voltage “C” for operation.
4. Faulty ECM or PCM (rare).
Code Solutions P0697.
1. Use a diagnostic scanner to retrieve freeze frame data and all associated trouble codes. This information can help pinpoint the root cause of the issue.
2. Inspect the wiring harness and connectors in the sensor reference voltage “C” circuit for any signs of damage, corrosion, or loose connections. Repair or replace damaged components as needed.
3. Test the continuity of the wiring in the sensor reference voltage “C” circuit using a multimeter. Ensure there are no open circuits present.
4. Check the sensor requiring sensor reference voltage “C” for proper operation. Test the sensor according to manufacturer-specific procedures outlined in the vehicle’s service manual. Replace the sensor if it is faulty.
5. If the wiring, connectors, and sensors are in good condition but the code persists, it may indicate a fault in the ECM or PCM. In this case, the ECM or PCM may need to be replaced or reprogrammed by a qualified technician.
6. After any repairs are made, clear the trouble codes and perform a test drive to verify that the issue has been resolved. If the code returns, further diagnosis may be necessary to identify the underlying problem.
7. Follow manufacturer-specific diagnostic procedures outlined in the vehicle’s service manual to accurately diagnose and repair issues related to the sensor reference voltage “C” circuit. If needed, seek assistance from a qualified technician or dealership.