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
Diagnostic Fault Information
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 and also supplies a varying voltage to the fuel tank fuel pump module in order to maintain the desired fuel line pressure.
Conditions for Running the DTC
* DTC P018B, P018C, P018D, P0231, P0232, P023F, P0641, P064A, or P0606 are not active.
* Fuel pump control is enabled and the fuel pump control state is normal.
* The system voltage is greater than 11 V.
* The engine has been running for more than 30 seconds.
* Low fuel level warning not present.
* The DTC runs continuously when the above conditions are met.
Conditions for Setting the DTC
This DTC sets when the fuel pump power control module detects a predetermined fuel pressure performance degradation between the desired fuel pressure and the actual fuel pressure.
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 [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Sunshade - Left Front
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 Testing
1. Ignition ON.
2. Verify DTCs P018B, P018C, P018D, P0231, P0232 or P023F are 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. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the G12 fuel pump. It may take up to 2 minutes for all vehicle systems to power down.
4. Test for less than 10 ohms between the low reference circuit terminal 2 and ground.
• If 10 ohms or greater
1. Ignition OFF, disconnect the harness connector at the fuel pump power control module.
2. Test for less than 2 ohms in the low reference circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the fuel pump power control module.
• If less than 10 ohms
5. Connect a test lamp between the supply voltage circuit terminal 1 and the low reference circuit terminal 2.
6. Ignition ON.
7. Verify the test lamp turns ON and OFF when commanding the fuel pump ON and OFF with a scan tool.
• If the test lamp is always OFF
1. Ignition OFF, disconnect the harness connector at the fuel pump power control module.
2. Test for infinite resistance between the supply voltage circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the supply voltage circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the fuel pump power control module.
• If the test lamp is always ON
1. Ignition OFF, disconnect the harness connector at the fuel pump power control module, ignition ON.
2. Test for less than 1 V between the supply voltage circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the fuel pump power control module.
• If the test lamp turns ON and OFF
8. Verify the proper fuel system pressure. Refer to Fuel System Diagnosis Fuel System Diagnosis.
• If the fuel system pressure test is not normal
Repair the fuel system as necessary.
• If the fuel system pressure test is normal
9. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Direct Fuel Injector Replacement Direct Fuel Injector Replacement
* Fuel Feed Hose Replacement Fuel Feed Hose Replacement
* Fuel Feed Pipe Replacement (With Direct Injection) Fuel Feed Pipe Replacement (With Direct Injection)
* Fuel Line Replacement - Chassis Fuel Line Replacement - Chassis
* Fuel Pump Power Control Module Replacement
* Fuel Tank Fuel Pump Module Replacement Fuel Tank Fuel Pump Module Replacement