Fuel Pump Control Module, Checking

Fuel Pump Control Module, Checking

Special tools, testers and auxiliary items required

• Multimeter.

• Wiring diagram.

Test requirements

• Fuse (SC1) OK.

• Fuse (S132) OK.

• Battery voltage at least 12.5 volts.

• All electrical consumers such as, lights and rear window defroster, switched off.

• Vehicles with automatic transmission, selector lever in position "P" or "N".

• A/C switched off.

• Ground (GND) connections between engine/transmission/chassis OK.

• Ignition switched off.

Test procedure

- Perform a preliminary check to verify the customer's complaint. Refer to => [ Preliminary Check ] Preliminary Check

- Remove access cover beneath the carpet on the passenger side of the luggage compartment

Checking voltage

Switch the ignition on.

- Using a Multimeter, check the following wiring connection for voltage.





Specified value: Battery voltage

- Switch the ignition off.

If the specified value was not obtained:

- Check the Fuel Pump (FP) Control Module (J538) wiring harness terminal 3 to the Battery B (+) terminal for an open circuit or short to Ground (GND).

- Check the Fuel Pump (FP) Control Module (J538) wiring harness terminal 2 to the B (+) terminal for an open circuit or short to B+.

- Check the electrical harness connectors for damage, corrosion, loose or broken terminals.

- If necessary, repair the wiring connection.

If no malfunctions are found in the wiring:

- Switch the ignition on.

- Using a Multimeter, check the following wiring connection for voltage.





Specified value: about 5 V

- Switch the ignition off.

If the specified value was not obtained:

- Check the Fuel Pump (FP) Control Module (J538) wiring harness terminal 5 to the Engine Control Module (ECM) (J623) harness connector T94a, terminal 35 for an open circuit or short to Ground (GND).

- Check for an open circuit or short to Ground (GND).

- Check the electrical harness connector for damage, corrosion, loose or broken terminals.

- If necessary, repair the wiring connection.

If no malfunctions are found in the wiring:

Checking Ground (GND)

- Using a Multimeter, check the Fuel Pump (FP) Control Module (J538) wiring harness terminal 4/31 to chassis ground for resistance.





Specified value: 1.5 ohms maximum.

If the specified value was not obtained:

- Check the Fuel Pump (FP) Control Module (J538) 4/31 to ground connection 6 (main wiring harness) for an open circuit or a short to Battery (+).

- Check the electrical harness connector for damage, corrosion, loose or broken terminals.

- If necessary, repair the wiring connection.

If no malfunctions are found in the wiring and the voltage supply was OK:

- Replace the Fuel Pump (FP) Control Module (J538).

- Perform a road test to verify repair.

If the fault does not return:

Repair complete, Generate readiness code. Refer to => [ Readiness Code ] Monitors, Trips, Drive Cycles and Readiness Codes.

- End diagnosis.

If the fault does return and no malfunction is detected in the wiring and the voltage supply was OK:

- Replace the Engine Control Module (ECM) (J623). Refer to => [ Engine Control Module, Replacing ] Engine Control Module, Replacing.

- Assembly is performed in the reverse of the removal.

After the repair work, the following work steps must be performed in the following sequence:

1. Check the DTC memory. Refer to => [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Mode 03 - Read DTC Memory.

2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Mode 04 - Erase DTC Memory.

3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Monitors, Trips, Drive Cycles and Readiness Codes.