P1089

DTC P1089

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC P1089
- Fuel Rail/System Pressure Performance During Deceleration Fuel Cut Off

Circuit/System Description

The Engine Control Module (ECM) monitors the fuel rail pressure deviation when the vehicle is in a speed deceleration condition and the fuel command request is at zero. The fuel rail pressure deviation needs to exceed 5 MPa while in fuel cutoff for approximately 80 seconds of cumulative deceleration, this may take multiple drive cycles.

Conditions for Running the DTC

* Ambient air temperature is above -7°C (19°F).

* Fuel temperature is between 0-80°C (32-176°F).

* Fuel system status is in fuel shut off mode during deceleration.

* Engine temperature is greater the 50°C (122°F).

* Engine speed is between 950-1850 RPM.

* Accelerator pedal position is less than.05 percent.

* Boost pressure is between 75 and 150 kPa.

* Vehicle speed greater than 0 mph.

* The DTC runs continuous when the above conditions exist.

Conditions for Setting the DTC

Rail pressure deviation is greater than 5 MPa (725 PSI) while in fuel cutoff for approximately 80 seconds of cumulative deceleration.

Action Taken When the DTC Sets

DTC P1089 is a Type B DTC.

Conditions for Clearing the DTC

DTC P1089 is a Type B DTC.

Diagnostic Aids

* This Diagnostic parameter is stored in the ECM over a period of time. Time to set this DTC may take several drive cycles.

* A restricted, kinked, or damaged fuel supply line including restricted fuel filter may cause this DTC to set.

* Water or contaminated fuel may cause this DTC to intermittently set. Refer to Contaminants-in-Fuel Diagnosis Contaminants-in-Fuel Diagnosis.

* When ambient temperatures are below 0°C (32°F), the fuel tank pickup screen may be iced over from water in the fuel tank.

* When power enhancing devices have been attached to the fuel rail pressure sensor circuits, this DTC may set and adversely affect the fuel system components.

Reference Information

Schematic Reference

Engine Controls Schematics [1][2]Electrical Diagrams

Connector End View Reference

Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)

Description and Operation

Fuel System Description Fuel System Description

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References Control Module References for scan tool information.

Circuit/System Verification

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

• If another DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.

• If another DTC is not set

2. Verify the proper fuel is used. Refer to Fuel System Specifications [1][2]Fuel Delivery and Air Induction and Contaminants-in-Fuel Diagnosis Contaminants-in-Fuel Diagnosis.

3. Verify there are no aftermarket performance enhancing devices installed on the vehicle.

4. Operate the vehicle within the Conditions for Running the DTC to verify that the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.