WOMS
P code powertrain High severity

P0680 ECM/PCM Power Relay Control Circuit

The OBD2 code P0680 indicates a malfunction in the power relay control circuit for the Engine Control Module (ECM) or Powertrain Control Module (PCM), which can affect the operation of the engine management system

Definition

The OBD2 code P0680 indicates a malfunction in the power relay control circuit for the Engine Control Module (ECM) or Powertrain Control Module (PCM), which can affect the operation of the engine management system

Common causes

  • Faulty ECM/PCM
  • Bad power relay
  • Open or shorted wiring in the relay circuit
  • Poor ground connection
  • Blown fuse
  • Corroded connectors
  • Faulty ignition switch

Common misdiagnoses

  • Faulty ECM/PCM
  • Bad power relay
  • Wiring issues or shorts
  • Battery problems
  • Ignition switch failure
  • Ground connection issues
  • Faulty fuses
  • Sensor malfunctions

Troubleshooting steps

  1. 1. Check the OBD-II System

    Use an OBD-II scanner to confirm the P0680 code and check for any additional codes that may provide more context about the issue

  2. 2. Inspect the ECM/PCM Power Relay

    Locate the ECM/PCM power relay in the fuse box or relay panel

  3. 3. Inspect the relay for any signs of damage, corrosion, or burnt contacts

  4. 4. If possible, swap the relay with a similar one (if available) to see if the problem persists

  5. 5. Check the Relay Circuit

    Use a multimeter to test the relay circuit for continuity and proper voltage

  6. 6. Check the relay terminals for proper voltage when the ignition is turned on

  7. 7. Ensure that the relay is receiving power from the battery and that the ground circuit is intact

  8. 8. Inspect Wiring and Connectors

    Visually inspect the wiring and connectors associated with the ECM/PCM power relay for any signs of damage, fraying, or corrosion

  9. 9. Ensure that all connections are secure and free of dirt or moisture

  10. 10. Test the ECM/PCM

    If the relay and wiring appear to be in good condition, the issue may lie within the ECM/PCM itself

  11. 11. Check for any software updates or recalls related to the ECM/PCM

  12. 12. If necessary, perform a bench test of the ECM/PCM or consult a professional for further diagnosis

  13. 13. Check Fuses

    Inspect any fuses related to the ECM/PCM and the power relay circuit. Replace any blown fuses

  14. 14. Look for Short Circuits

    Check for any short circuits in the wiring that could be causing the relay to malfunction

  15. 15. Use a multimeter to test for continuity between wires that should not be connected

  16. 16. Clear Codes and Test Drive

    After performing repairs or replacements, clear the trouble codes using the OBD-II scanner

  17. 17. Take the vehicle for a test drive to see if the code reappears

  18. 18. Consult a Professional

    If the issue persists after following these steps, it may be necessary to consult a professional mechanic or technician for further diagnosis.Additional Tips: - Always refer to the vehicle's service manual for specific wiring diagrams and relay locations. - Ensure that you are working in a safe environment and take necessary precautions when dealing with electrical components. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the P0680 code