The engine control module (ECM) provides ignition voltage to the coil side of the fuel pump relay whenever the engine is cranking or running. The control module enables the fuel pump relay as long as the engine is cranking or running, and ignition system reference pulses are received. If no ignition system reference pulses are received, the control module turns OFF the fuel pump. The fuel pump relay control circuit is equipped with a feedback circuit that is pulled up to 2.5 volts within the ECM. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.

The following conditions may cause the fuel pump fuse to open:

Schematic Reference

Engine Controls Schematics

Description and Operation

Fuel System Description

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 43244 Relay Puller Pliers

Note: Fuel pump DTCs may set when using the Fuel Pump output control.

1. Ignition ON, command the fuel pump relay ON with a scan tool. You should hear the fuel pump operate for 3-5 seconds and then turn OFF.
2. If the vehicle passes the Circuit/System Verification Test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.

1. Ignition OFF, the fuel pump should not be operating.

⇒	If the fuel pump operates continuously, test for a short to voltage in supply voltage circuit of the fuel pump. If the circuit/connections test normal, replace the fuel pump relay.

2. Test the fuel pump fuse. The fuse should not be open.

⇒	If the fuel pump fuse is open, test for a short to ground in the supply voltage circuit of the fuel pump. If the circuit/connections test normal, replace the fuel pump.

3. Ignition OFF, remove the fuel pump relay from the electrical center.
4. Ignition ON, test for battery voltage between the B+ voltage circuit of the fuel pump relay and ground.

⇒	If less than B+, repair the B+ voltage circuit of the fuel pump relay for an open/high resistance.

5. Connect a 15A fused jumper wire between the B+ circuit of the fuel pump relay and the supply voltage circuit of the fuel pump. The fuel pump should operate.

⇒	If the fuel pump does not operate, test for the following conditions:

•	An open/high resistance in the supply voltage circuit of the fuel pump

•	An open/high resistance in the ground circuit of the fuel pump

⇒	If the above circuit/connections test normal, replace the fuel pump.

6. If all circuit/connections test normal, test or replace the fuel pump relay.

1. Measure for 135-185 ohms between terminals 85 and 86 of the fuel pump relay.

⇒	If the resistance is not within the specified range, replace the fuel pump relay.

2. Measure for infinite resistance between the following terminals of the fuel pump relay:

•

30 and 86

•

30 and 87

•

30 and 85

•

85 and 87

⇒	If continuity is detected, replace the fuel pump relay.

3. Connect a 15A fused jumper wire from the positive terminal of the battery to relay terminal 85. Connect a jumper wire from the negative terminal of the battery to relay terminal 86. Measure for less than 2 ohms between terminals 30 and 87 of the relay.

⇒	If the resistance measures more than 2 ohms, replace the fuel pump relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.