P0670
Glow Plug Module Control Circuit
The control circuit between the engine controller and the glow plug control module reports a fault. The ECU can no longer reliably command the module that drives the glow plugs, so cold-start pre-heating may not run. On a diesel this causes hard starting, white smoke, and rough running until warm. Causes: open or shorted wiring between ECU and glow plug module, a failed module, or a power/ground fault at the module.
The control circuit between the engine controller and the glow plug control module reports a fault. The ECU can no longer reliably command the module that drives the glow plugs, so cold-start pre-heating may not run. On a diesel this causes hard starting, white smoke, and rough running until warm. Causes: open or shorted wiring between ECU and glow plug module, a failed module, or a power/ground fault at the module.
Common causes
- high
Glow plug control module faulty
One of the most commonly reported causes for this code — check this first.
Typical part cost: $170-770
- medium
Wiring or connector fault
A plausible cause — test and verify before replacing parts.
Typical part cost: $170-770
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
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Frequently asked questions
What does P0670 mean?
P0670 means "Glow Plug Module Control Circuit". It is a generic OBD-II code that points to a fault in the computer & auxiliary output controls.
What are the most common causes of P0670?
glow plug control module faulty; wiring or connector fault — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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