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 12.5 V.

• Fuse (S228) (position 28) OK

• Fuel Pump (FP) Relay (J17) OK.

• Ignition switched off.

Test sequence

- Open cover of fuse box at left side of instrument cluster.

- Connect Hand held remote control (jumper) between right terminal of socket from fuse S228 and vehicle battery B+.

- Press button of remote control.

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

If no operating noise can be heard:

- Remove the rear seat bench.

CAUTION!
Wear protective gloves!

- Remove right locking flange cover - arrows -.





- Disconnect the electrical harness connector - 1 - from the fuel delivery unit.





- Connect a multimeter between terminals 1 and 4 of the electrical harness connector and test for voltage.





- Press switch of remote control.

Specified value: approx. battery voltage

If the specified value was not obtained:

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

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

- If necessary, repair the faulty wiring connection.

If specified value is obtained, although no running-noise can be heard at pump:

- Check if the electrical wiring between the flange and fuel pump is connected and has continuity





If no malfunction is detected in the wires, replace the fuel pump.

- Install fuel delivery unit.

Final procedures

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

1. Check the DTC memory..

2. If necessary, erase the DTC memory..

3. If the DTC memory was erased, generate readiness code.

- End diagnosis and switch the ignition off.