The engine control module (ECM) provides a voltage to the coil side of the fuel pump relay. When the ignition switch is first turned ON, the ECM turns ON the fuel pump relay, which applies power to the fuel pump. The ECM enables the fuel pump relay as long as the engine is cranking or running, and crankshaft reference pulses are received. If no crankshaft reference pulses are received, the ECM turns OFF the fuel pump relay after about 3 seconds.

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

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

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

1. Ignition ON, command the fuel pump relay ON with a scan tool. You should hear the fuel pump operate for 2-3 seconds and then turn OFF.
2. 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.

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+, test the B+ voltage circuit of the fuel pump relay for an open/high resistance.

5. Connect a 15 A 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. Test for 110-150 Ω between terminals 1 and 2 of the fuel pump relay.

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

2. Measure the resistance between the terminals of the fuel pump relay listed below. The DMM should display O.L.

•

3 and 2

•

3 and 5

•

3 and 1

•

1 and 5

⇒	If less than the specified value, replace the fuel pump relay.

3. Connect a 15 A fused jumper wire from the positive terminal of the battery to relay terminal 1. Connect a jumper wire from the negative terminal of the battery to relay terminal 2. Test for less than 2 Ω between terminals 3 and 5 of the relay.

⇒	If greater than the specified range, replace the fuel pump relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.