Service Information

Captiva

DTC P037E or P037F - LNP or LNQ

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 Descriptors

DTC P037E 00: Glow Plug Control Module Feedback Circuit Low Voltage

DTC P037F 00: Glow Plug Control Module Feedback Circuit High Voltage

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
B+	-	P0383 00	-	-
Ignition	P0383 00	P0383 00	P0384 00	-
Signal	P037E 00	P037E 00	P037F 00	-
Ground	-	-	-	-

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 engines 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

•	The ignition is ON.

•	The ignition voltage is between 9-16 V.

•	The DTCs run once per ignition cycle when the above conditions are met.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

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 P037E 00 or P037F 00 should not be 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 X1 at the K34 Glow Plug Control Module.
Test for less than 5 Ω between the ground circuit terminal 3 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

Connect a test lamp between the B+ circuit terminal 5 and ground.

⇒	If the test lamp is OFF, test the B+ circuit for a short to ground or an open/high resistance.

Ignition ON, connect a test lamp between the ignition circuit terminal 4 and ground.

⇒	If the test lamp is OFF, test the ignition circuit for a short to ground or an open/high resistance.

Test for 10-11 V between the signal circuit terminal 1 and ground.

⇒	If greater than the specified range, test the signal circuit for a short to voltage.

⇒	If less than the specified range, test the signal circuit for a short to ground or an open/high resistance.

If the circuit tests normal, replace the K34 Glow Plug Control Module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Glow Plug Controller Replacement

•	Control Module References for ECM replacement, setup, and programming