Fuel Pump Electrical Testing

Fuel Pump, Electrical Testing

Special tools, testers and auxiliary items required
- Hand held remote control (jumper).
- Multimeter.
- Electrical connector test lead set.

Test conditions
- Battery voltage min. 12.5 V.
- Fuel filter OK.
- Fuse S228 (position 28) OK.
- Fuel Pump (FP) Control Module J538 OK.
- Fuel tank at least 1 / 4 filled.
- Ignition switched off.

Test sequence
- Remove the rear seat bench.







- Remove the screws - arrows - and the right locking flange.







- Remove the wiring harness and the electrical harness connector - arrow - from locking flange opening and position aside.







- Disconnect fuel delivery unit electrical harness connector - arrow -.







- Push the battery cover to the right - arrow 1 - and remove it upward - arrow 2 -.







- Release the retaining clip - arrow A - and open the positive terminal cover - 2 -.
- Connect a Hand held remote control (jumper) to terminal - 1 - of the fuel delivery unit and to vehicle battery (+).







- Connect a jumper cable from a Electrical connector test lead set to terminal - 4 - of the fuel delivery unit and to vehicle Ground (GND).
- Press the Hand held remote control (jumper) switch in.

NOTE: The Fuel Pump (FP) runs quietly. Avoid surrounding noises while testing the fuel pump.

The fuel pump should operate and an audible noise heard.
If no operating noise is heard:







- Remove the fuel delivery unit.
- Using a Multimeter , check the fuel delivery unit electrical terminals 1 to 4 for continuity.

Specified value: 0 Ohm.

If the specified value is not obtained:
- Check the fuel delivery unit for damage, corrosion, lose or broken terminals.
- Check the fuel delivery unit for an open circuit, short to Ground (GND), or short to Battery (+).
- Repair the electrical circuit as necessary.

If no malfunction is detected in electrical circuit, replace the fuel delivery unit.

Assembly is performed in reverse order.