2010 Cadillac CTS Sedan AWD V6-3.0L Page 1984
* DTC P018B, P018C, P018D, P0231, P0232, P023F, P064A, P1255 or P06A6 are not active.
* DTC P0641 has not failed this ignition cycle.
* 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.
Conditions for Setting the DTC
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.
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.
Reference Information
Schematic Reference
Engine Controls Schematics (LLT) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)Engine Controls Schematics
(LF1) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Fuel System Description (See: Powertrain Management/Computers and Control Systems/Description and Operation/Fuel System Description)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit
Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code
(DTC) Type Definitions)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning)for scan tool information
Circuit/System Testing
1. Verify that DTCs P018C, P018D, P0231, P0232, or P023F are not set.
瀚慖f the DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic
Trouble Code (DTC) List - Vehicle).
2. Ignition OFF, disconnect the harness connector at the G12 fuel pump.
3. Ignition ON, test for less than 5.0 ohm between the G12 fuel pump low reference circuit terminal 2 and ground.
瀚慖f 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.
4. Ignition OFF, install a test lamp between the control circuit terminal 1 and the low reference circuit terminal 2.
5. 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
