2010 Cadillac CTS Sedan AWD V6-3.6L Page 2001
Circuit/System Description
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 remains active for 2 seconds, unless the engine is in crank or run. While this voltage is being received,
the fuel pump control module closes the ground switch of the fuel pump and also supplies a varying voltage to the fuel tank pump module in order
to maintain the desired fuel rail pressure.
Conditions for Running the DTC
* 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.
