2010 Cadillac Truck SRX FWD V6-3.0L Page 1625

2010 Cadillac Truck SRX FWD V6-3.0L Page 1625

* 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.

2. Connect a test lamp between the enable circuit terminal 20 of the fuel pump control module and ground.

3. Ignition ON, command the ECM Fuel Pump Enable ON and OFF with a scan tool. The test lamp should turn ON and OFF as commanded.

瀚慖f the test lamp remains OFF all the time, test for a short to ground or an open/high resistance on the enable circuit. If circuit/connections

test normal, replace the K20 ECM.

瀚慖f the test lamp remains ON all the time, test for a short to voltage on the enable circuit. If circuit/connections test normal, replace the K20

ECM.

4. Ignition ON, test for 2-3 V on the enable circuit terminal 20 of the fuel pump control module.

瀚慖f not within the specified range, replace the K20 ECM.

5. If all circuits/connections test normal, replace the K27 fuel pump control module.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM or fuel pump control module replacement, setup,

and programming

P0629

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.