On Board Diagnostic (OBD)

Fuel Pump, Checking

• Battery voltage at 12.5 V

• Fuse for Fuel Pump (FP) on fuse holder OK.

- Switch ignition on.

• Fuel Pump (FP) must briefly start up.

• Fuel Pump (FP) runs quietly.

- Switch off ignition.

If Fuel Pump (FP) does not start up

- Remove the seat bench

- Remove the cover - 1 - from fuel delivery unit. Arrow - 2 - points in direction of travel.





• On vehicles with auxiliary heater, harness connector of Metering Pump (V54) must also be disconnected.

- Disconnect connector - 1 -.





- Connect Low current voltage tester () to outer terminals of connector.





- Switch ignition on.

• LED must light up briefly.

If LED does not light up briefly:

- Locate and repair open circuit in wiring.

LED lights up briefly (voltage supply OK)

- Remove fuel delivery unit.

- Check if electrical wiring between flange and fuel pump is connected.

If no open circuits are found:

- Fuel Pump (FP) faulty, replace 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. 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 ] Readiness Code.