Table A1-7A Fuel System Diagnosis (Fuel Pump Relay Check)

Fuel System Diagnosis (Fuel Pump Relay Check):

Fuel System Diagnosis (Fuel Pump Relay Check)(continued):

Electrical Schematic:

Circuit Description

When the ignition switch is turned to the "ON" position, the Powertrain Control Module (PCM) will energize the fuel pump relay for 2 seconds, allowing for fuel pump operation. When the fuel pump relay is de-energized, the fuel pump stops operating. If the engine is being cranked, or is running, the fuel pump will continue to operate, as long as the PCM is receiving ignition reference pulses. If the ignition reference pulses are not detected, the fuel pump will stop after 2 seconds.


Diagnostic Aids

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

Number(s) below refer to the step number(s) on 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. Checks fuel pump operation with ignition switch in the "ON" position.

3. Checks fuel pump relay switch for power.