Service Information

Captiva

DTC P0002-P0004 - 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 P0002 00: Fuel Pressure Regulator 1 Circuit Resistance Too High

DTC P0003 00: Fuel Pressure Regulator 1 Control Circuit Low Current

DTC P0004 00: Fuel Pressure Regulator 1 Control Circuit High Current

Circuit/System Description

The fuel pressure regulator solenoid is used to control the fuel pressure from the high pressure fuel pump to the fuel rail. The fuel pressure regulator solenoid is pulse width modulated (PWM). An ignition voltage is supplied to the fuel pressure regulator solenoid. The ECM controls the solenoid by grounding the control circuit with a solid state device called a driver. If the fuel pressure regulator solenoid current is above or below a calibrated value, these DTCs will set

Conditions for Running the DTC

•	The ignition is ON or the engine is running.

•	The ignition voltage is less than 16 V.

•	The DTC runs continuously once the above conditions are met.

Conditions for Setting the DTC

P0002 00

The ECM detects the fuel rail pressure regulator solenoid control circuit current is above a calibrated value for less than 1 s.

P0003 00

The ECM detects the fuel rail pressure regulator solenoid control circuit current is below a calibrated value for less than 1 s.

P0004 00

The ECM detects the fuel rail pressure regulator solenoid control circuit current is above a calibrated value for less than 1 s.

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. DTCs P0002 00, P0003 00 or P0004 00 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 Q18 Fuel Pressure Regulator.
Ignition ON, verify a test lamp illuminates between the ignition voltage circuit terminal 2 and ground.

⇒	If the test lamp does not illuminate, repair the ignition voltage circuit for a short to ground or an open/high resistance.

Ignition ON, command the Q18 Fuel Pressure Regulator ON with a Scan Tool and test for 6.5-7.5 V between the control circuit terminal 1 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.

⇒	If greater 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 all circuits test normal, test or replace the Q18 Fuel Pressure Regulator.

Component Testing

Static Test

Ignition OFF, disconnect the harness connector at the Q18 Fuel Pressure Regulator.
Test for 6-7 Ω between the control terminal 1 and the ignition voltage terminal 2.

⇒	If not within the specified range, replace the Q18 Fuel Pressure Regulator.

Test for infinite resistance between each terminal and the Q18 Fuel Pressure Regulator housing.

⇒	If not the specified value, replace the Q18 Fuel Pressure Regulator.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Fuel Injection Pump Replacement

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