2010 Cadillac CTS Sedan AWD V6-3.0L Page 1534

2010 Cadillac CTS Sedan AWD V6-3.0L Page 1534

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 0 RPM.

* The ignition voltage is between 11-18 V.

* The DTCs run continuously when the conditions above are met.

Conditions for Setting the DTC

* The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match.

* The above condition is met for a minimum of 2.5 s.

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)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

1. Attempt to start the engine. Observe the DTC information with a scan tool. DTC P0627, P0628, or P0629 should not set.

2. Ignition ON, command the fuel pump ON and OFF with a scan tool while observing the following control circuit status parameters:

* Fuel Pump Enable Circuit Low Voltage Test Status

* Fuel Pump Enable Circuit Open Test Status

* Fuel Pump Enable Circuit High Voltage Test Status

Each parameter should toggle between OK and Not Run or Not Run and OK.

3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the

conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

1. Ignition OFF, disconnect the K27 fuel pump control module harness connector.