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.

NOTE: 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.