Circuit Diagnosis - Fuel Pump Relay

Wiring Diagram:

Circuit Description
The Powertrain Control Module (PCM) will energize the fuel pump relay for 3 seconds when the ignition switch is turned to the ON position. When the fuel pump relay is energized the fuel pump will operate and pressurize the fuel system. When the engine is being cranked, or is running, the PCM will receive ignition system reference pulses and will continue to energize the fuel pump relay as long as the ignition system reference pulses are detected. The fuel pump will stop after 3 seconds when the ignition is ON, unless the PCM receives ignition system reference pulses.

Diagnostic Aids
A restricted or leaking fuel feed pipe or hose will cause an Engine Cranks But Will Not Start condition. Check the fuel sender assembly connections inside of the fuel tank for poor connections.

An intermittent malfunction may be caused by a poor connection, rubbed through wire insulation, or a wire broken inside the insulation. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal-to-wire connections before component replacement.

Test Description
The numbers below refer to the Step numbers in the Diagnostic Table.
1. The Powertrain OBD System Check prompts the technician to complete some basic checks and store the freeze frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
2. This step checks the fuel pump operation with the ignition switch in the ON position.
3. This step checks for an open in the fuel pump relay control circuit before the replacement of the PCM.