The P0670 trouble code indicates an issue with the glow plug module control circuit. Glow plugs are used in diesel engines to preheat the combustion chamber for easier cold starts. The glow plug control module manages the operation of the glow plugs based on signals from the engine control module (ECM) or powertrain control module (PCM). When the PCM detects a fault in the glow plug module control circuit, it triggers the P0670 code.
Glow Plug Module Control Circuit
Code symptoms P0670.
1. Check Engine Light (CEL) illuminated on the dashboard.
2. Difficulty starting the engine, especially in cold weather.
3. Rough idle or misfiring during cold starts.
4. Decreased engine performance and fuel efficiency, especially during cold starts.
5. Other related trouble codes may be present, depending on the specific issue.
This code is common in brands such as:: Chevrolet, Renault, Ford, Toyota, Nissan, Mercedes Benz, Honda.
Causes of the code P0670.
1. Faulty glow plug module.
2. Wiring or connector issues in the glow plug module control circuit, such as corrosion, damaged wires, or loose connections.
3. Failed glow plugs.
4. Faulty engine control module (ECM) or powertrain control module (PCM).
Code Solutions P0670.
1. Use a diagnostic scanner to retrieve freeze frame data and all associated trouble codes. This information can help pinpoint the root cause of the issue.
2. Inspect the wiring and connectors related to the glow plug module control circuit for any signs of damage, corrosion, or loose connections. Repair or replace damaged components as needed.
3. Test the glow plug module using a scan tool capable of bi-directional control to ensure it is functioning properly. Replace the module if it is found to be faulty.
4. Test the glow plugs using a digital multimeter to ensure they are within the specified resistance range. Replace any faulty glow plugs.
5. If the wiring, connectors, and glow plugs are in good condition but the code persists, it may indicate a fault in the ECM or PCM. In this case, the module may need to be replaced or reprogrammed by a qualified technician.
6. After any repairs are made, clear the trouble codes and perform a test drive to verify that the issue has been resolved. If the code returns, further diagnosis may be necessary to identify the underlying problem.
7. Follow manufacturer-specific diagnostic procedures outlined in the vehicle’s service manual to accurately diagnose and repair issues related to the glow plug module control circuit. If needed, seek assistance from a qualified technician or dealership.