P2635

DTC P2635

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 Descriptor

DTC P2635
- Fuel Pump Flow Performance

Circuit/System Description

The engine control module (ECM) supplies voltage to the fuel pump power control module when the ECM detects that the ignition is on. The voltage from the ECM to the fuel pump power control module remains active for 2 seconds, unless the engine is in crank or run. While this voltage is being received, the fuel pump power control module closes the ground switch of the fuel pump. The fuel pump power control module maintains correct fuel pressure based on the information from the fuel pressure sensor and varying the PWM controlled current to the fuel pump.

Conditions for Running the DTC

* DTC P018B, P018C, P018D, P0231, P0232, P023F, P0641, P064A, P0606, P1255, P129E, or P12A6 are not active.

* Fuel pump control is enabled and the fuel pump control state is normal.

* The ignition voltage is between 11-32 V.

* The engine has been running for more than 30 seconds.

* The engine fuel flow is not 0.

* Low fuel level warning not present.

* The DTC runs continuously when the conditions above are met.

Conditions for Setting the DTC

The fuel pump power control module detects a difference of ± 60 kPa at 400 kPa request or ±45 kPa at 300 kPa request between the desired fuel pressure and the actual fuel pressure for approximately 10 s.

Action Taken When the DTC Sets

DTC P2635 is a Type B DTC.

Conditions for Clearing the DTC

DTC P2635 is a Type B DTC.

Diagnostic Aids

Using the Failure Records data may help locate an intermittent condition. If you cannot duplicate the DTC, the information in the Failure Records can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can help determine how many ignition cycles that the diagnostic test reported a pass and/or a fail.

On vehicles equipped with a high pressure mechanical pump on Direct Fuel Injection engines, the vehicle may continue to run even though the pump in the fuel tank is not operating.

Reference Information

Schematic Reference

Engine Controls Schematics (LHU) [1][2]Electrical Diagrams

Connector End View Reference

Component Connector End Views Sunshade - Left

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.

2. Verify that DTC P018B, P018C, P018D, P0231, P0232, or P023F is not set.

• If any of the DTCs are set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.

• If none of the DTCs are set

3. Verify the scan tool Short Term Fuel Pump Trim and the Long Term Fuel Pump Trim when multiplied together are less than 1.5.

• If greater than 1.5
Refer to Circuit/System Testing.

• If less than 1.5

4. Verify the scan tool Fuel Pressure Sensor and the Desired Fuel Pressure are within 45 kPa (6.5 psi) at 300 kPa (43.5 psi) request or 60 kPa (8.7 psi) at 400 kPa (58 psi) request of each other while operating the vehicle through varying loads.

• If greater than 45 kPa (6.5 psi)/60 kPa (8.7 psi)
Refer to Circuit/System Testing.

• If less than 45 kPa (6.5 psi)/60 kPa (8.7 psi)

5. 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.

6. Verify the DTC does not set.

• If the DTC sets
Refer to Circuit/System Testing.

• If the DTC does not set

7. All OK.

Circuit/System Testing

Note: Do not replace the fuel pump power control module based on a history DTC P2635. DTC P2635 may be stored but that does not indicate a failure of the fuel pump power control module. Refer to Strategy Based Diagnosis Strategy Based Diagnosis for further history DTC diagnostics.

1. Verify the proper fuel system pressure. Refer to Fuel System Diagnosis Fuel System Diagnosis.

• If the fuel pressure is not normal
Repair the fuel system as necessary.

• If the fuel pressure is normal

2. All OK.

Repair Instructions

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

* Direct Fuel Injector Replacement Service and Repair

* Fuel Feed Pipe Replacement Service and Repair

* Fuel Tank Fuel Pump Module Replacement (NT7) Fuel Tank Fuel Pump Module Replacement (NT7)Fuel Tank Fuel Pump Module Replacement (NU6) Fuel Tank Fuel Pump Module Replacement (NU6)

* Perform the Fuel Pump Trim Reset procedure with a scan tool after the repair.

Repair Verification

1. Install any components that have been removed or replaced during diagnosis.

2. Perform any adjustments, programming or setup procedures that are required when a component is removed or replaced.

3. Clear the DTCs with a scan tool.

4. Turn OFF the ignition for 60 s.

5. Operate the vehicle within the Conditions for Running the DTC.

6. Verify the scan tool Short Term Fuel Pump Trim and the Long Term Fuel Pump Trim when multiplied together are less than 1.5.

• If greater than 1.5
Refer to Circuit/System Testing.

• If less than 1.5

7. Verify the scan tool Fuel Pressure Sensor and the Desired Fuel Pressure are within 45 kPa (6.5 psi) at 300 kPa (43.5 psi) request or 60 kPa (8.7 psi) at 400 kPa (58 psi) request of each other while operating the vehicle through varying loads.

• If greater than 45 kPa (6.5 psi)/60 kPa (8.7 psi)
Refer to Circuit/System Testing.

• If less than 45 kPa (6.5 psi)/60 kPa (8.7 psi)

8. All OK.