FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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Fuel Pump Control Module, Checking







Fuel Pump Control Module, Checking

Special tools, testers and auxiliary items required

Multimeter

Wiring diagram.

Test requirements

Fuse (SB2) 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

Start diagnosis

- Remove the rear seat bench. Refer to the appropriate service manual.

- Remove the fuel delivery unit cover located under the right rear seat. Refer to the Repair Manual for seat removal.

The Fuel Pump Control Module is between floor panel and fuel delivery unit (right-side). The Fuel Pump Control Module is mounted on top of the fuel tank and will require the tank assembly to be removed for accessing the module and harness. Refer to the Repair Manual for removal procedure.

When the door is opened the fuel pump is activated for 2 seconds to build up the pressure in the fuel system.

Models with an airbag are installed with a fuel shut - off system. It reduces the danger of a fire in a crash as the fuel pump is switched off via the fuel pump relay.

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 for an open or grounded circuit between terminal 5 and fuse SB 2 in Fuse Panel B.

- Check the wiring connection for damage, corrosion, loose or broken terminals.

- If necessary, repair the faulty wiring connection.

- Repair the circuit and replace any open fuses.

- Go to Final procedures

If the specified value was obtained:

Checking Ground (GND)

- Using a Multimeter, check the Fuel Pump (FP) Control Module (J538) wiring harness terminal 5 to Terminal 4, for proper ground.

Switch the ignition ON.

Specified value: Battery voltage

- Switch the ignition OFF.

If the specified value was Not obtained:

- Check for an open ground circuit

- Check the wiring connection for damage, corrosion, loose or broken terminals.

- If necessary, repair the faulty wiring connection.

- Go to Final procedures

If the specified value was obtained:

- Using a Multimeter, check the Fuel Pump (FP) Control Module (J538) wiring harness to the Engine control module (J623) , connector T94 for resistance.






Specified value: 1.5 ohms or Less

If the specified value was Not obtained:

- Check for an open circuit

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

- If necessary, repair the wiring connection.

- Go to Final procedures

If the specified value was obtained:

- Replace the Fuel Pump (FP) Control Module (J538). Refer to the appropriate service manual.

- Perform a road test to verify repair.

If the fault does not return:

Generate readiness code. Refer to => [ Readiness Code ] Programming and Relearning.

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 the appropriate service manual.

Final procedures

- Reinstall the fuel delivery unit cover located under the right rear seat. Refer to the Repair Manual for seat removal.

- Reinstall the rear seat bench. Refer to the appropriate service manual.

- 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 Modes 01 - 09.

2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09.

3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Programming and Relearning.