2010 Cadillac Truck SRX AWD V6-3.0L Page 1622

2010 Cadillac Truck SRX AWD V6-3.0L Page 1622

DTC P0627-P0629

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System

Check - Vehicle) prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an

overview of the diagnostic approach.

* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure

Instructions) provides an overview of each diagnostic category.

DTC Descriptors

DTC P0627

- Fuel Pump Enable Circuit

DTC P0628

- 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 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 (LAU) (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/Connector End Views By Name)

Electrical Information Reference

* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit

Testing/Circuit Testing)

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General