The engine control module (ECM) provides a ground 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

Description and Operation

Fuel System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Special Tools Required

J 43244 Relay Puller Pliers

1. Ignition ON, command the fuel pump relay ON and OFF with a scan tool. You should hear and feel a click when you command the fuel pump relay ON and 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 List.

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

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

2. Ignition OFF, remove the fuel pump relay from the electrical center with the J 43244 .
3. Test for less than 5 ohms of resistance between the ground circuit and ground .

⇒	If greater than the specified range, repair the ground circuit for an open/high resistance.

4. Ignition ON, verify a test lamp illuminates between the B+ circuit and ground.

⇒	If the test lamp does not illuminate, repair the B+ circuit for a short to ground or an open/high resistance.

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

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

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

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

⇒	If the above circuits test normal, replace the fuel pump.

6. Ignition OFF, connect a test lamp between the control circuit and ground.
7. Ignition ON, command the fuel pump relay ON and OFF with a scan tool. The test lamp should turn ON and OFF with each command.

⇒	If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.

⇒	If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.

8. If all circuits test normal, test or replace the fuel pump relay.

1. Test for 70-110 ohms of resistance between terminals 85 and 86.

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

2. Test 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 not within the specified value, replace the fuel pump relay.

3. Connect a 20A fused jumper wire between relay terminal 85 and 12 volts. Connect a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms of resistance between terminals 30 and 87.

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.