The P0683: Glow Plug Control Module to PCM Communication Circuit code indicates a communication issue between the glow plug control module and the Powertrain Control Module (PCM). This communication link is essential for proper coordination of the glow plug system, which helps in starting diesel engines, particularly in cold weather. A fault in the communication circuit, wiring issues, or problems with the control module or PCM can trigger this code.
P0683 – Quick Overview
| Code | Information |
|---|---|
| Meaning | P0683: Glow Plug Control Module to PCM Communication Circuit |
| Is it serious? | Yes, as it can prevent proper control of the glow plugs, leading to hard starts or failure to start, especially in cold weather. |
| Possible causes | – Faulty communication circuit between glow plug control module and PCM – Wiring issue – Faulty glow plug control module or PCM |
| How to diagnose? | – Test communication circuit between glow plug control module and PCM – Inspect wiring and connectors – Replace glow plug control module or PCM if necessary |
P0683 Meaning
The P0683 code indicates a communication failure between the Glow Plug Control Module and the PCM (Powertrain Control Module). This communication link is critical for controlling the operation of the glow plugs, which heat the engine cylinders for easier starting. Without proper communication, the glow plugs may not function as intended, leading to starting issues, particularly in cold weather.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to check for additional codes related to the PCM, glow plug control module, or other electrical faults that might give more context. | OBD-II Scanner |
| Test the Communication Circuit Between Glow Plug Control Module and PCM | Use a multimeter to check for continuity and voltage in the communication circuit between the glow plug control module and the PCM. Ensure the wiring is intact and the voltage is within specification. | Multimeter |
| Inspect Wiring and Connectors | Inspect the wiring and connectors leading to and from the glow plug control module and PCM for damage, loose connections, or corrosion that could interfere with communication. | Flashlight, Multimeter |
| Test the Glow Plug Control Module | Use a diagnostic tool to test the functionality of the glow plug control module. Ensure it is sending and receiving signals correctly. Replace if faulty. | Diagnostic Tool, Multimeter |
| Test the PCM | Test the PCM to ensure it is properly communicating with the glow plug control module. Replace the PCM if communication is faulty and cannot be restored. | Diagnostic Tool, Multimeter |
| Replace the Glow Plug Control Module or PCM if Necessary | If the glow plug control module or PCM is faulty and cannot be repaired, replace the necessary module to restore proper communication and glow plug function. | Replacement Module, Tools |
| Clear the Code and Test | After repairs, clear the code using an OBD-II scanner and test the vehicle to ensure proper communication between the glow plug control module and the PCM. | OBD-II Scanner, Vehicle Manual |
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I test OBD-II scanners and make DIY Engine diagnostics guides to help you solve your car problems without having to depend on the mechanic. A lot of them will try to scam you or are just no help at all. About Juraj Lukacko