DTC P2635 (Fuel Pump Control Module)
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DTC P2635 (Fuel Pump Control Module)
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DTC P2635
Fuel Pump Flow Performance
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Diagnostic Fault Information
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Circuit
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Short to Ground
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Open or High Resistance
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Short to Voltage
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Signal Performance
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Control
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P0231
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P023F
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P0232
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P023F, P2635
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Low Reference
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-
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P023F
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-
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P023F, P2635
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Circuit/System Description
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The engine control module (ECM) supplies voltage to the fuel pump control module when the ECM detects that the ignition is on. The voltage from the ECM to the fuel pump control module is active for 2 seconds if the engine is not in one of the modes for Crank (starting) or Run (driving). When this activity voltage is received, the fuel pump's control module closes the fuel pump's ground switch and supplies a varying voltage to the fuel pump module in the tank in order to maintain the desired fuel line pressure.
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Conditions for Running the DTC
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DTC P018B, P018C, P018D, P0231, P0232, P023F, P064A, P1255 or P06A6 are not active.
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DTC P0641 has not failed this ignition cycle.
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Fuel pump control is enabled and the fuel pump control state is normal.
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The system voltage is greater than 11 V.
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The engine has been running for more than 30 seconds.
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Conditions for Setting the DTC
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This DTC sets when the fuel pump control module detects a predetermined fuel pressure performance degradation between the desired fuel rail pressure and the current estimated fuel rail pressure.
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Action Taken When the DTC Sets
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DTC P2635 is a Type B DTC.
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Conditions for Clearing the DTC
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DTC P2635 is a Type B DTC.
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 with direct injection engines and mechanical high-pressure pump the vehicle can be driven for a time even if the pump in the fuel tank is not working.
Schematic Reference
Engine Controls Schematics (3.0L (LF1))
Engine Controls Schematics (2.8L (LAU))
Connector End View Reference
Component Connector End Views
Description and Operation
Fuel System Description (LF1)
Fuel System Description (LAU or LY7)
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References
for scan tool information
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1.
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Verify that DTCs P018C, P018D, P0231, P0232, or P023F are not set.
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Note
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Do not replace K27 fuel pump control module based on DTC P2635 in History. DTC P2635 can be stored without a fault in the fuel pump control module. See
Strategy Based Diagnosis
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3.
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Ignition OFF, disconnect the harness connector at the G12 fuel pump.
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4.
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Ignition ON, test for less than 5.0 Ω between the G12 fuel pump low reference circuit terminal B and ground.
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5.
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If greater than the specified range, test the G12 fuel pump low reference circuit for a high resistance. If the circuit tests normal, replace the K27 fuel pump control module.
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6.
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Ignition OFF, install a test lamp between the control circuit terminal A and the low reference circuit terminal B.
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7.
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Ignition ON, command the Fuel Pump Relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
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8.
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If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K27 fuel pump control module.
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9.
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If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K27 fuel pump control module.
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11.
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If the fuel pressure is not normal, replace the G12 fuel pump
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12.
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If all circuits test normal, replace the K27 fuel pump control module.
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Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
