WOMS
P code powertrain Medium severity

P067C Cylinder 5 Glow Plug Control Circuit Low

The OBD2 code P067C indicates a low voltage or malfunction in the glow plug control circuit for cylinder 5, which can affect the engine's ability to start and run efficiently in cold conditions

Definition

The OBD2 code P067C indicates a low voltage or malfunction in the glow plug control circuit for cylinder 5, which can affect the engine's ability to start and run efficiently in cold conditions

Common causes

  • Faulty glow plug
  • Damaged wiring or connectors
  • Failed glow plug control module
  • Poor electrical connections
  • Blown fuse
  • Short circuit in the glow plug circuit
  • Corroded terminals

Common misdiagnoses

  • Faulty glow plug
  • Bad glow plug relay
  • Wiring issues or shorts in the circuit
  • Faulty engine control module (ECM)
  • Incorrectly diagnosed fuel system issues
  • Injector problems
  • Compression issues in the cylinder
  • Faulty temperature sensor
  • Battery or charging system problems
  • General electrical issues in the vehicle

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other related trouble codes. This can provide more context and help identify if there are multiple issues

  2. 2. Inspect the Glow Plug

    Visual Inspection: Check the glow plug for any signs of damage, corrosion, or wear. If the glow plug is faulty, it may need to be replaced

  3. 3. Resistance Test

    Use a multimeter to measure the resistance of the glow plug. A typical glow plug should have a resistance of around 0.5 to 5 ohms. If the resistance is significantly higher or infinite, the glow plug may be faulty

  4. 4. Check the Glow Plug Control Module

    Inspect the glow plug control module for any signs of damage or corrosion. Ensure that all connections are secure and free of debris

  5. 5. Test the control module according to the manufacturer’s specifications to ensure it is functioning correctly

  6. 6. Inspect Wiring and Connectors

    Check the wiring and connectors leading to the glow plug and the control module. Look for frayed wires, loose connections, or corrosion that could cause a poor electrical connection

  7. 7. Repair or replace any damaged wiring or connectors

  8. 8. Test the Glow Plug Relay

    If the vehicle is equipped with a glow plug relay, test it to ensure it is functioning properly. A faulty relay can prevent the glow plugs from receiving power

  9. 9. Check Power and Ground

    Use a multimeter to check for proper voltage at the glow plug when the ignition is turned on. You should see battery voltage at the glow plug terminal

  10. 10. Also, check the ground connection for the glow plug circuit to ensure it is solid and free of corrosion

  11. 11. Inspect Engine Control Module (ECM)

    If all other components check out, there may be an issue with the ECM. Ensure that the ECM is receiving the correct signals and is functioning properly. This may require specialized diagnostic equipment

  12. 12. Clear Codes and Test Drive

    After performing repairs or replacements, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns

  13. 13. Consult Repair Manual

    If the issue persists, consult the vehicle’s repair manual for specific diagnostic procedures and specifications related to the glow plug system

  14. 14. Seek Professional Help

    If you are unable to diagnose or fix the issue, consider seeking help from a qualified mechanic or technician who has experience with diesel engines and glow plug systems. By following these steps, you should be able to identify and resolve the issue associated with the P067C code