P0629-FUEL PUMP CONTROL CIRCUIT HIGH





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 RELAY CONTROL CIRCUIT SHORTED TO VOLTAGE
(K31) FUEL PUMP RELAY 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).
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 VOLTAGE



Turn the ignition off.
Disconnect the TIPM C1 harness connector.
Disconnect the ECM harness connectors.
Remove the ASD Relay from the TIPM.
Connect a jumper wire between cavity 30 and cavity 87 of the ASD Relay Connector.
Turn the ignition on.
Measure the voltage of the (K31) Fuel Pump Control circuit in the TIPM harness connector.

Is there any voltage present?

Yes


No

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



Turn the ignition off.
Remove the jumper wire and install the ASD Relay.
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