WOMS
P code powertrain Medium severity

P069B Cylinder 9 Glow Plug Control Circuit High

The OBD2 code P069B indicates a problem with the glow plug control circuit for cylinder 9, specifically that the circuit is reading a high voltage or resistance, which may suggest a malfunction in the glow plug or its...

Definition

The OBD2 code P069B indicates a problem with the glow plug control circuit for cylinder 9, specifically that the circuit is reading a high voltage or resistance, which may suggest a malfunction in the glow plug or its control system

Common causes

  • Faulty glow plug
  • Open or shorted wiring in the glow plug circuit
  • Bad glow plug control module
  • Poor electrical connections
  • Faulty engine control module (ECM)
  • Corroded connectors
  • Blown fuse in the glow plug circuit

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
  • Misidentified injector problems
  • Battery or charging system issues
  • Faulty temperature sensor
  • Issues with other glow plug circuits

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. Ensure that it is properly seated in the cylinder head

  3. 3. Resistance Test

    Use a multimeter to measure the resistance of the glow plug. A typical glow plug should have a resistance value within the manufacturer's specifications (usually a few ohms). If it reads open or significantly out of range, it may need replacement

  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 dirt or moisture

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

  6. 6. Inspect Wiring and Connectors

    Check the wiring harness and connectors leading to the glow plug and control module for any signs of damage, fraying, or corrosion

  7. 7. Look for any loose connections or broken wires that could cause a high resistance in the circuit

  8. 8. Test the Power Supply

    Use a multimeter to check for proper voltage at the glow plug and control module. Ensure that the voltage is within the specified range when the glow plug is activated

  9. 9. If there is no power, trace back to the fuse and relay associated with the glow plug system

  10. 10. Check for Ground Issues

    Ensure that the ground connections for the glow plug and control module are secure and free of corrosion. A poor ground can lead to high resistance and trigger the code

  11. 11. Inspect Engine Control Module (ECM)

    If all other components check out, there may be an issue with the ECM. Ensure that it is functioning correctly and that it is programmed for the specific vehicle and engine configuration

  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. Seek Professional Help

    If the issue persists after performing these steps, it may be best to consult a professional mechanic or technician who has experience with diesel engines and glow plug systems. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the P069B code