The Ford P0684 code is an error code that is associated with the Glow Plug Module Communication Signal Performance. When this code is triggered, it indicates that the Engine has started, the system voltage is at 11-15.0v, and the Powertrain Control Module (PCM) has detected an unexpected voltage condition on the Glow Plug Communication Module (GPCM) to PCM signal circuit. This code can cause a range of issues with the vehicle, and it is important to understand the various causes and solutions associated with the Ford P0684 code.
Causes and Solutions of the Ford P0684 Code
| Cause | Solution |
|---|---|
| Glow Plug Module communication circuit to the PCM is open or shorted to ground | Check the wiring harness for damage, corrosion, and loose connections. |
| GPCM circuit is picking up EMI or RFI noise | Inspect the GPCM for damage and make sure it is properly insulated. |
| PCM malfunctions | Replace the PCM if it is malfunctioning. |
| Glow Plug Module overheated | Replace the GPCM if it is overheated. |
Glow Plug Module Communication Circuit to the PCM is Open or Shorted to Ground
When the Ford P0684 code is triggered, it indicates that the Glow Plug Module (GPCM) communication circuit to the Powertrain Control Module (PCM) is open or shorted to ground. To fix this issue, it is important to inspect the wiring harness for any damage. Additionally, check for corrosion and loose connections. If any of these issues are present, they should be fixed immediately to ensure that the code does not resurface.
GPCM Circuit is Picking Up EMI or RFI Noise
The GPCM circuit may be picking up EMI or RFI noise, which can also trigger the Ford P0684 code. To fix this issue, it is important to inspect the GPCM for any damage and make sure it is properly insulated. If any damage is present, the GPCM should be replaced to ensure that the code does not resurface.
PCM Malfunctions
The Ford P0684 code can be triggered if the Powertrain Control Module (PCM) malfunctions. If the PCM is malfunctioning, it should be replaced in order to ensure that the code does not resurface.
Glow Plug Module Overheated
The Ford P0684 code can also be triggered if the Glow Plug Module (GPCM) overheats. If the GPCM is overheated, it should be replaced in order to ensure that the code does not resurface.
Conclusion
In conclusion, the Ford P0684 code is an error code that is associated with the Glow Plug Module Communication Signal Performance. This code can cause a range of issues with the vehicle, and it is important to understand the various causes and solutions associated with the Ford P0684 code. The most common causes of this code include a malfunctioning Powertrain Control Module (PCM), an open or shorted GPCM communication circuit, EMI or RFI noise, and an overheated GPCM. It is important to inspect and replace these components if necessary in order to ensure that the code does not resurface. By understanding and addressing the common causes of the Ford P0684 code, drivers can ensure that their vehicles are running smoothly and safely.
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