Cruze

DTC P0089

The engine control module (ECM) uses commanded fuel pump flow to determine a desired fuel rail pressure. The ECM monitors fuel rail pressure with the fuel rail pressure sensor. The Fuel Pressure Regulator Solenoid is used to control the fuel pressure at the fuel rail. The Fuel Pressure Regulator Solenoid is pulse width modulated (PWM). The engine control module (ECM) supplies the voltage directly to the Fuel Pressure Regulator Solenoid. The ECM controls the solenoid by grounding the control circuit with a solid state device called a driver.

P0089 00

The ECM detects that the fuel rail pressure is above the maximum threshold while the pressure is controlled by the fuel rail pressure regulator.

P0089 11

The ECM detects that the fuel rail pressure is above the maximum threshold while the pressure is controlled by the fuel rail pressure regulator.

P0089 12

The ECM detects that the fuel rail pressure is below the minimum threshold when the pressure is controlled by the fuel pressure regulator.

P0089 18

Positive deviation and set point value of the fuel volume flow through the fuel pressure regulator exceeded concerning set flow of fuel.

P0089 19

Negative rail pressure deviation and the set point value of fuel volume through the fuel pressure regulator is less than or equal to the minimum value.

Schematic Reference

Engine Controls Schematics : LLW

Connector End View Reference

Component Connector End Views

Description and Operation

Fuel System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

For equivalent regional tools, refer to Special Tools .

1. Ignition ON, observe the DTC information with a scan tool. Verify that no other DTCs are set.

⇒	If any other DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.

2. Engine running, observe the scan tool DTC information parameter. DTCs P0087, P0088, or P0089 should not set.
3. 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.

1. Ignition ON, command the fuel pump relay ON and OFF with a scan tool. Verify the fuel pump turns ON.

⇒	If the fuel pump does not turn ON, refer to Fuel Pump Electrical Circuit Diagnosis for further diagnosis.

2. Ignition OFF, install the EN 49799 Fuel Pressure Gauge Adapter and the EN 49495 Fuel Pressure Gauge to the fuel supply pipe at the fuel filter assembly. Refer to Fuel Pressure Gauge Installation and Removal .
3. Ignition ON, verify the fuel pressure is between 414-483 kPa (60-70 PSI).

⇒	If not within the specified range, refer to Fuel System Diagnosis for further diagnosis.

4. Ignition OFF, disconnect the harness connector at the Q18 Fuel Pressure Regulator.
5. Ignition ON, verify a test lamp illuminates between the ignition 1 voltage circuit terminal 1 and ground.

⇒	If the test lamp does not illuminate, repair the ignition 1 voltage circuit for a short to ground or an open/high resistance.

6. Ignition ON, test for 3-4 V between the control circuit terminal 2 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.

7. Inspect and repair one of the following conditions:

Low Pressure

•	A fuel system leak

•	Restricted fuel filter

•	Injection nozzle stuck in open position

•	Leakage in the fuel rail pressure regulator

•	Worn fuel injection pump

High Pressure

•	Restricted fuel return

•	Fuel injection pump stuck open

•	Fuel pressure regulator stuck closed

•	Restricted fuel injector

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.