Fuel Pump (FP), Electrical Testing

Fuel Pump (FP), Electrical Testing







Recommended special tools and equipment
- 3087 wrench for tank sensor
- V.A.G 1348/3A remote control with V.A.G 1348/3-2 adapter cable
- V.A.G 1526A multimeter
- V.A.G 1594A connector test kit

Test requirements:
- Battery voltage at least 12.5 V
- Fuse S228 OK (position 28)
- Fuel Pump (FP) Relay OK; checking. Fuel Pump (FP) Relay -J17- and Activation, Checking
- 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. V.A.G 1348/3A remote control connection using adapter cables from V.A.G 1348/3-2 at right terminal of socket from fuse S228 (arrow).
- 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:
- Remove rear seat bench.







- Remove cover for right connector flange -arrows-.







- Carefully disengage and disconnect electrical 4-pin harness connector (arrow).







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

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


WARNING: Fuel system is under pressure. Before opening system, place rags around the connection. Then release pressure by carefully loosening connection.







- Mark fuel supply line -1- and fuel return line -2- and disconnect from connector flange (right side of vehicle).

WARNING: Connector flange may only be opened when fuel tank is maximum 1/4 full. Otherwise, a large amount of fuel will spill out. Empty fuel tank if necessary. Procedure.







- Use 3087 wrench to remove locking ring.
- Pull connector flange and sealing ring from opening of fuel tank.







- 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:

If no malfunction is detected in wires, Fuel Pump (FP) is faulty - replace fuel pump.
- Install Fuel Pump (FP).