WOMS
P code powertrain Medium severity

P0654 Malfunction Indicator Lamp (MIL) Control Circuit Open

The OBD2 code P0654 indicates that there is an open circuit in the Malfunction Indicator Lamp (MIL) control circuit, which prevents the MIL from functioning properly

Definition

The OBD2 code P0654 indicates that there is an open circuit in the Malfunction Indicator Lamp (MIL) control circuit, which prevents the MIL from functioning properly

Common causes

  • Open circuit in the MIL control circuit
  • Faulty Engine Control Module (ECM)
  • Damaged wiring or connectors
  • Short circuit to ground or power
  • Faulty MIL indicator bulb
  • Poor ground connection
  • Corroded or loose connectors

Common misdiagnoses

  • Faulty Engine Control Module (ECM)
  • Bad wiring or connectors
  • Faulty Malfunction Indicator Lamp (MIL)
  • Issues with other sensor circuits
  • Faulty ignition switch
  • Battery or charging system problems
  • Faulty ground connections

Troubleshooting steps

  1. 1. Check the MIL (Check Engine Light)

  2. 2. Ensure that the MIL bulb is functioning properly. If the bulb is burned out, it may not illuminate when there is a fault

  3. 3. Inspect Wiring and Connectors

  4. 4. Visually inspect the wiring and connectors associated with the MIL control circuit. Look for signs of damage, corrosion, or loose connections

  5. 5. Pay special attention to the wiring harness that connects to the Engine Control Module (ECM) and the MIL

  6. 6. Test the MIL Circuit

  7. 7. Use a multimeter to check for continuity in the MIL circuit. Disconnect the connector from the ECM and test the resistance of the circuit

  8. 8. Check for any shorts to ground or power in the circuit

  9. 9. Check the ECM

  10. 10. If the wiring and connectors are in good condition, the issue may lie within the ECM itself. Check for any software updates or known issues with the ECM for your specific vehicle model

  11. 11. If possible, test the ECM with a known good unit to see if the problem persists

  12. 12. Inspect Related Components

  13. 13. Check other components that may be related to the MIL circuit, such as fuses and relays. Ensure that all fuses related to the engine management system are intact

  14. 14. Clear the Code and Test Drive

  15. 15. After performing any repairs or adjustments, clear the trouble code using an OBD-II scanner and take the vehicle for a test drive to see if the code returns

  16. 16. Consult Technical Service Bulletins (TSBs)

  17. 17. Look for any TSBs related to the P0654 code for your specific vehicle make and model. Manufacturers may have specific recommendations or known fixes for this issue

  18. 18. Seek Professional Help

  19. 19. If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or technician who has experience with your vehicle's make and model. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the P0654 code