Circuit Diagnosis - Fuel Pump

Diagram Chart:

Electrical:

CIRCUIT DESCRIPTION

The Fuel Pump relay coil is supplied power via the Engine Controls Power Relay (switched B+). The Engine Control Module (ECM) controls the relay by grounding the control circuit via an internal solid state device called a driver. When the ECM detects reference pulses from the Crankshaft Position sensor, the ECM will enable the fuel pump. On the switch side of the relay, one of the relay contacts is connected directly to battery positive voltage (B+). The relay controls the power to the Fuel Pump fuse and the fuel pump.

DIAGNOSTIC AIDS

Use the Connector Test Adapter Kit J 35616-A for any test that requires probing the ECM harness connector or a component harness connector. Using this kit will prevent damage to the harness connector terminals.

The following conditions may have caused the fuel pump fuse to open:

^ The fuse was damaged

^ There is an intermittent short in the fuel pump power feed circuit.

^ The fuel pump has an intermittent internal problem.