MotoLogic P0087, P0088, P0089 User Manual

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DTC P0087, P0088, or P0089

Applies to:

2.8L, 3.0L, 3.2L, or 3.6L

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 P0087

Fuel Rail Low Pressure

DTC P0088

Fuel Rail High Pressure

DTC P0089

Fuel Pressure Regulator Performance

Circuit/System Description

The fuel rail pressure sensor detects fuel pressure within the fuel rail. The engine control module (ECM) provides a

5 V reference voltage on the 5 V reference circuit and ground on the low reference circuit. The ECM receives a

varying signal voltage on the signal circuit.

High pressure fuel is regulated by the high pressure fuel pump actuator, which is a part of the high pressure fuel

pump. The high pressure fuel pump actuator is a solenoid valve. The ECM provides a voltage on the actuator high

control circuit and ground on the actuator low control circuit. Both circuits are controlled through output drivers

within the ECM. When deactivated, both drivers are disabled. When activated, the high control circuit driver

energizes the high pressure fuel pump actuator and the low control circuit driver pulse-width modulates (PWM) the

low control circuit to ground.

The high pressure mechanical fuel pump is driven by three lobes on the camshaft. The ECM uses the camshaft and

crankshaft position sensor inputs to synchronize the high pressure fuel pump actuator with the position of each of

the camshaft lobes. The ECM regulates fuel pressure by adjusting the portion of each pump stroke that provides

fuel to the rail.

The ECM monitors the fuel rail fuel pressure sensor and the high pressure fuel pump actuator to determine if the

commanded and actual pressure are within a predetermined range, or if the amount of fuel pressure correction

exceeds a calibrated pressure.

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Conditions for Running the DTC

DTC P0090, P0091, P0092, P0191, P0192, or P0193 is not set.

The ignition 1 signal parameter is between 10–18 V.

The engine start temperature is greater than −48°C (−54°F).

The fuel level is greater than 11 %.

The deceleration fuel cut-off (DFCO) is inactive.

The engine speed is greater than 600 RPM once during engine start for greater than 5 s.

The air bag is not deployed.

DTCs P0087, P0088, and P0089 run continuously when the above conditions are met for 5 s.

Conditions for Setting the DTC

P0087

The actual fuel rail pressure is 1 MPa (145 psi) less than the desired fuel pressure. The condition exists for greater

than 5 s.

P0088

The actual fuel rail pressure is 2 MPa (290 psi) greater than the desired fuel rail pressure. The condition exists for

greater than 5 s.

P0089

The high pressure fuel pump actuator command necessary to maintain the desired fuel rail pressure is +/−2 MPa

(290 psi) of the command expected by the controller. The condition exists for greater than 5 s.

Action Taken When the DTC Sets

DTCs P0087, P0088, and P0089 are Type A DTCs.

A message center or an indicator displays Reduced Engine Power.

Conditions for Clearing the DTC

DTCs P0087, P0088, and P0089 are Type A DTCs.

Diagnostic Aids

A restricted fuel feed pipe between the fuel feed pipe fuel pressure sensor and the high pressure fuel

pump may set a DTC.

A condition with the fuel tank fuel pump module or the fuel pump flow control module may set a DTC.

A skewed fuel rail pressure sensor, or an intermittent condition in the fuel rail pressure sensor circuits may

set a DTC.

A leaking or restricted fuel injector may set a DTC.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

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Description and Operation

Fuel System Description

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

1. Observe the DTC information with a scan tool. DTC P029D, P02A1, P02A5, P02A9, P02AD, P02B1,

P0627, P0628, P0629, P069E, or U0109 should not set.

If a DTC is set refer to Diagnostic Trouble Code (DTC) List - Vehicle.

Attempt to start and idle the engine.
Observe the DTC information with a scan tool. DTCs P0087, P0088, and P0089 should not set.
Engine idling, observe the Fuel Rail Pressure Sensor parameter with a scan tool. The pressure should be

approximately 3.5–5.5 Mpa (508–798 psi).

Command an increase and decrease in fuel rail pressure with a scan tool. Observe the scan tool Fuel Rail
Pressure Sensor parameter. The Fuel Rail Pressure Sensor should increase or decrease with each commanded
state.

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

Note: Circuit/System Verification must be performed first or misdiagnosis may result.

1. Ignition ON, observe the scan tool fuel pump control module fuel line pressure sensor parameter.

Command an increase in the fuel line pressure with a scan tool. Verify the fuel line pressure increases to

greater than 414 kPa (60 psi) as commanded.

If the less than the specified range, refer to Fuel System Diagnosis.

Note: As little as 2 Ω on either circuit of the high pressure fuel pump actuator will cause these DTCs to set. Test the

circuits of the high pressure fuel pump actuator for a high resistance if you suspect a condition.

Remove the G18 high pressure fuel pump and visually inspect the lobes on the camshaft for unusual wear.

If the lobes appear normal, replace the G18 high pressure fuel pump.

If the lobes are worn, replace the camshaft.

Component Testing

Static Test

1. Ignition OFF, disconnect the harness connector at the high pressure fuel pump.

Note: The DMM and test leads must be calibrated to 0 Ω in order to prevent misdiagnosis.

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2. Test for 0.35–0.6 Ω at 20°C (68°F) of resistance between low control circuit terminal 1 and high control

circuit terminal 2.

If the resistance is less than 0.3 Ω or greater than 0.6 Ω, replace the high pressure fuel pump.

Test for infinite resistance between each terminal and the high pressure fuel pump housing/case.

If not the specified value, replace the high pressure fuel pump.

Dynamic Test

Engine idling, command the Fuel Pressure Control to Increase with a scan tool. The Fuel Rail Pressure Sensor

parameter should increase with each command.

If the Fuel Rail Pressure Sensor parameter does not increase with each command, replace the

high pressure fuel pump.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Camshaft Removal - Left Side

Fuel Pump Replacement

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