DTC P0670
Diagnostic Instructions
DTC Descriptor
DTC P0670 01: Glow Plug Control Module Control Circuit Short to Battery
DTC P0670 02: Glow Plug Control Module Control Circuit Short to Ground
DTC P0670 04: Glow Plug Control Module Control Circuit Open
DTC P0670 54: Glow Plug Control Module Control Circuit High Temperature
Circuit/System Description
The glow plug controller is a solid state device which operates the glow plugs. The temperature and the power consumption is controlled between the engine control module (ECM) and the glow plug controller within a wide range to suit the engine pre-heating requirements. The ECM controls the glow plug module with a pulse-width modulated (PWM) control circuit. The glow plug initial ON time will vary based on the system voltage and temperature. Lower temperatures cause longer ON times.
Conditions for Running the DTC
P0670 01 or P0670 54
• | The ignition is ON or the engine is running. |
• | The ignition voltage is between 9-16 V. |
• | The DTCs run once per ignition cycle when the above conditions are met. |
P0670 02 or P0670 44
• | The ignition voltage is between 9-16 V. |
• | The DTCs run once per ignition cycle when the above conditions are met. |
Conditions for Setting the DTC
The ECM detects an open, short to ground, or a short to voltage on the glow plug module control circuit for greater than 0.5 s.
Action Taken When the DTC Sets
DTC P0670 is a Type C DTC.
Conditions for Clearing the DTC
DTC P0670 is a Type C DTC.
Reference Information
Schematic Reference
Engine Controls Schematics : LLW
Connector End View Reference
Component Connector End Views
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Ignition ON, observe the DTC information with a scan tool. DTC P0670 should not set.
- Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the glow plug control module.
- Ignition ON, test for greater than 10 V between the glow plug control module control circuit terminal 10 and ground.
⇒ | If less than the specified range, test the control circuit for an open or a short to ground. If the circuit tests normal, replace the K20 Engine Control Module. |
- Test the alternating current (AC) frequency from the glow plug control module control circuit terminal 10. Command the glow plug control module ON with a scan tool. Verify the AC frequency is between 30-35 Hz.
⇒ | If less than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module. |
⇒ | If greater than the specified range, test the control circuit for a high resistance. If the circuit tests normal, replace the K20 Engine Control Module. |
- If the circuit tests normal, test or replace the K34 Glow Plug Control Module.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
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