P0628-FUEL PUMP CONTROL CIRCUIT LOW





For a complete wiring diagram Refer to Section 8W

Theory of Operation


When the ignition switch is on, the Totally Integrated Power Module (TIPM) sends a 12 volt signal to the ECM on the Fuel Pump Relay Control circuit. The ECM grounds this signal to indicate a request for Fuel Pump operation.



Possible Causes
INTERMITTENT DTC
(K31) FUEL PUMP CONTROL CIRCUIT SHORTED TO GROUND
(K31) FUEL PUMP CONTROL CIRCUIT OPEN OR HIGH RESISTANCE
TOTALLY INTEGRATED POWER MODULE

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)



Diagnostic Test

1. DTC IS ACTIVE

Ignition on, engine not running.
With the scan tool, Clear DTCs in the Engine Control Module (ECM).
With the scan tool, actuate the Fuel Pump.
Monitor the scan tool for at least two minutes.
With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes


No

2. (K31) FUEL PUMP CONTROL CIRCUIT SHORTED TO GROUND



Turn the ignition off.
Disconnect the TIPM C1 harness connector.
Disconnect the Engine Control Module (ECM) harness connectors.
Measure the resistance between ground and the (K31) Fuel Pump Control circuit in the TIPM harness connector.

Is the resistance above 1000 ohms?

Yes


No

3. (K31) FUEL PUMP CONTROL CIRCUIT OPEN OR HIGH RESISTANCE



Measure the resistance of the (K31) Fuel Pump Control circuit between the TIPM harness connector and the ECM harness connector.

Is the resistance below 10.0 ohms?

Yes


No