For 1990-2009 cars only
Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC P064C: Glow Plug Module Control PerformanceDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Battery Positive Voltage | P064C | P064C | -- | -- |
Ignition 1 Voltage | P064C | P064C | -- | -- |
Typical Scan Tool Data
Circuit | Normal Range | Short to Ground | Open | Short to Voltage |
|---|---|---|---|---|
Operating Conditions: Ignition ON | ||||
Battery Positive Voltage | Battery Voltage | 0 Volts | 0 Volts | -- |
Circuit/System Description
The glow plug control module (GPCM) has the ability to perform internal diagnostics for voltage and output state of the glow plugs. The GPCM will send a message to the engine control module (ECM) to set this DTC.
Conditions for Running the DTC
| • | The ignition is ON. |
| • | DTC P064C runs continuously. |
Conditions for Setting the DTC
| • | The GPCM detects a variation between the main battery supply to the GPCM and battery supply to the ECM, or an internal condition for 3 second. |
| • | The GPCM detects a low voltage condition on the ignition 1 voltage circuit tot he GPCM. |
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records. |
Conditions for Clearing the DTC
| • | The control module turns OFF the 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. |
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
- If you cannot duplicate the conditions, refer to Testing for Intermittent Conditions and Poor Connections.
- Engine running, observe the DTC information with a scan tool. DTC P064C should not set.
- Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
- Ignition ON, verify the scan tool GPCM Ignition 1 Signal parameter is battery voltage.
- Ignition OFF, disconnect the C2 harness connector at the GPCM.
- Ignition ON, verify that a test lamp illuminates between the ignition 1 voltage circuit terminal 52 at the harness connector and ground.
- If all circuits test normal, replace the GPCM.
| ⇒ | If the Ignition 1 Signal parameter is not battery voltage, test the battery positive voltage circuit to the glow plug control module terminal C1/A for an open or short to ground. If the circuit tests normal, replace the GPCM. |
| ⇒ | If the test lamp does not illuminate, test the ignition 1 voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the GPCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for GPCM replacement, setup, and programming
