P0673: Glow Plug Control Module Circuit High

Definition

The OBD2 code P0673 indicates that there is a high voltage or an open circuit in the glow plug control module circuit for cylinder 3, which may affect the glow plug's operation

Common causes

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

Common misdiagnoses

Faulty glow plugs
Bad glow plug relay
Wiring issues or shorts
Faulty engine control module (ECM)
Fuel system problems
Injector issues
Battery or charging system problems
Incorrectly diagnosed engine temperature sensor issues
Air intake system problems
Exhaust gas recirculation (EGR) system faults

Troubleshooting steps

1. Check for Additional Codes

Use an OBD-II scanner to check for any other trouble codes that may be present. This can provide more context and help identify related issues
2. Inspect the Glow Plug Control Module
3. Visually inspect the glow plug control module for any signs of damage, corrosion, or loose connections
4. Ensure that the module is securely mounted and that all connectors are clean and free of debris
5. Test the Glow Plugs
6. Use a multimeter to test each glow plug for continuity. A faulty glow plug can cause the control module to read high
7. If any glow plugs are found to be defective, replace them
8. Check Wiring and Connectors
9. Inspect the wiring harness and connectors leading to the glow plug control module and glow plugs for any signs of damage, fraying, or corrosion
10. Repair or replace any damaged wiring or connectors
11. Test the Glow Plug Control Module
12. If the wiring and glow plugs are in good condition, the glow plug control module itself may be faulty
13. Consult the vehicle’s service manual for specific testing procedures for the control module
14. Check Power and Ground
15. Verify that the glow plug control module is receiving the correct voltage and ground. Use a multimeter to check for proper voltage at the module’s power and ground terminals
16. Inspect the Engine Control Module (ECM)
17. In some cases, the issue may stem from the ECM. Check for any software updates or known issues related to the ECM that could affect the glow plug control module
18. Clear Codes and Test Drive
19. After performing repairs, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns
20. Consult a Professional
21. If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician for further diagnosis. By following these troubleshooting steps, you should be able to identify and resolve the issue associated with the P0673 code

Definition

Common causes

Common misdiagnoses

Troubleshooting steps

1. Check for Additional Codes

2. Inspect the Glow Plug Control Module

3. Visually inspect the glow plug control module for any signs of damage, corrosion, or loose connections

4. Ensure that the module is securely mounted and that all connectors are clean and free of debris

5. Test the Glow Plugs

6. Use a multimeter to test each glow plug for continuity. A faulty glow plug can cause the control module to read high

7. If any glow plugs are found to be defective, replace them

8. Check Wiring and Connectors

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

10. Repair or replace any damaged wiring or connectors

11. Test the Glow Plug Control Module

12. If the wiring and glow plugs are in good condition, the glow plug control module itself may be faulty

13. Consult the vehicle’s service manual for specific testing procedures for the control module

14. Check Power and Ground

15. Verify that the glow plug control module is receiving the correct voltage and ground. Use a multimeter to check for proper voltage at the module’s power and ground terminals

16. Inspect the Engine Control Module (ECM)

17. In some cases, the issue may stem from the ECM. Check for any software updates or known issues related to the ECM that could affect the glow plug control module

18. Clear Codes and Test Drive

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

20. Consult a Professional

21. If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician for further diagnosis. By following these troubleshooting steps, you should be able to identify and resolve the issue associated with the P0673 code