The glow plug controller has the ability to perform internal diagnostics for voltage and output state of the glow plugs. If the glow plug controller senses an open in the main battery supply to the glow plug controller, or a condition with any of the glow plug driver circuits, the glow plug controller will send an error message to the engine control module (ECM).
This diagnostic procedure supports the following DTC:
DTC P0670 Glow Plug Module Control Circuit
CONDITIONS FOR RUNNING THE DTC
- DTC U0073 or U0106 is not set.
- The ignition is ON.
- DTC P0670 runs continuously.
CONDITIONS FOR SETTING THE DTC
The glow plug controller detects an open to the main battery supply for the glow plugs, or an open in all 8 glow plug circuits for less than 1 second.
ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
CONDITIONS FOR CLEARING THE MIL/DTC
- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.
P0670 Mercedes-Benz Glow Plug Control Module Circuit Fault
- Faulty Glow Plug Control Module (GPCM)
- GPCM harness is open or shorted
- GPCM circuit poor electrical connection
- Faulty Engine Control Module (ECM)
What about the obd code?
The Engine Control Module (ECM) has detected a fault on the Glow Plug Control Module (GPCM) control circuit
- Engine Light ON (or Service Engine Soon Warning Light)
- Lack/Loss of Power
- The engine may be harder to start
- Engine hesitation