2010 Cadillac CTS Sedan AWD V6-3.6L Page 1531
- Fuel Pump Enable Circuit Low Voltage
DTC P0629
- Fuel Pump Enable Circuit High Voltage
Diagnostic Fault Information
Circuit/System Description
The engine control module (ECM) provides ignition voltage to the fuel pump flow control module whenever the engine is cranking or running. The
control module enables the fuel pump flow control module as long as the engine is cranking or running, and ignition system reference pulses are
received. While this enable voltage is being received, the fuel pump flow control module supplies a varying voltage to the in-tank fuel pump
module in order to maintain the desired fuel line pressure.
Conditions for Running the DTC
* The engine speed is greater than 80 RPM.
* The ignition 1 signal parameter is 10-18 V.
* The ECM has commanded the fuel pump enable circuit ON and OFF at least once during the ignition cycle.
* The DTCs run continuously when the conditions above are met.
Conditions for Setting the DTC
P0627
The ECM detects the fuel pump enable circuit voltage is less than 2.74 V when the enable circuit is commanded OFF. The condition exists for
greater than 4 seconds, or a cumulative of 30 seconds.
P0628
The ECM detects the fuel pump enable circuit voltage is less than 2.21 V when the enable circuit is commanded ON. The condition exists for
greater than 4 seconds, or a cumulative of 30 seconds.
P0629
The ECM detects the fuel pump enable circuit voltage is greater than 2.21 V when the enable circuit is commanded OFF. The condition exists for
greater than 4 seconds, or a cumulative of 30 seconds.
Action Taken When the DTC Sets
DTCs P0627, P0628, and P0629 are Type B DTCs.
Conditions for Clearing the DTC
DTCs P0627, P0628, and P0629 are Type B DTCs.
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)
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)
