Fuel Pump Electrical, Testing

Fuel Pump (FP), Electrical Testing







Recommended special tools and equipment
- VAG1348/3A remote control with VAG1348/3-2 adapter cable
- VAG1526A multimeter
- VAG1594A connector test kit

Test requirements:
- Battery voltage at least 12.5 V
- Fuse S228 OK (position 28)
- Fuel Pump (FP) Relay OK; checking. Testing and Inspection
- Fuel filter OK
- Ignition switched off.

Test sequence
- Open cover of fuse box at left side of instrument cluster.
- Remove fuse S228 at fuse carrier (position 28) (left row, 5th large fuse from top).







- Connect e.g. VAG1348/3A remote control connection using adapter cables from VAG1348/3-2 at right terminal of socket from fuse S228 (position 28).
- Connect alligator clip to vehicle battery B+.
- Press switch of remote control.
- Operating noise of the pump must be audible in vicinity of fuel tank.

NOTE: Fuel Pump (FP) runs quietly. Surrounding noise should be avoided during test of the Fuel Pump (FP).

If no flowing noise can be heard:

Limousine:
- Remove luggage compartment lining.
- Push forward right backrest of rear seat, if necessary.

Avant:
- Remove left 1/3 backrest.
- Remove left side trim in luggage compartment and dirt tray.

All:







- Remove cover for connector flange (arrows).

Vehicles up to 06.03:







- Release and disconnect harness connector -1-.

Vehicles as of 07.03:







- Disconnect electrical harness connector -1- at connector flange.

All:







- Connect multimeter between terminal 1 and 4 of harness connector for voltage measurement.
- Press remote control switch.
- Specified value: approx. battery voltage

If specified value is obtained, although no operating noise can be heard from pump:
- Remove fuel pump.







- Check whether electrical wires between flange and Fuel Pump (FP) are connected, and test for continuity if necessary.

If no malfunctions are found in wires:
- Fuel Pump (FP) malfunctioning, replace fuel pump.
- Install Fuel Pump (FP) unit, observe measures after connecting battery when doing this.

Final procedures
After repair work, the following work steps must be performed in the mentioned sequence:
1. Check DTC memory. Diagnostic Mode 03 - Read DTC Memory
2. If necessary, erase DTC memory. Diagnostic Mode 04 - Erase DTC Memory
3. If DTC memory was erased, generate readiness code.

- End diagnosis and switch ignition off.