Left Fuel Delivery Unit With Transfer Fuel Pump, Electrical Testing

Left Fuel Delivery Unit with Transfer Fuel Pump, Electrical Testing





Special tools, testers and auxiliary items required

• (VAG1348/3A) with (VAG1348/3-2)

• (VAG1526A)

• (VAG1594A)

• (VAS5051) with (VAS5051/9)

Test Prerequisites

• Battery voltage at least 12.7 V

• Up to model year XXX: Fuse 10 on fuse holder SF10 (relay- and fuse holder, in luggage compartment, right side) OK





• From model year 2004: Fuse 2 on fuse holder SF2 (relay- and fuse holder, in luggage compartment, right side) OK

• Fuel Pump (FP) 2 Relay (J49) OK (in relay- and fuse holder, in luggage compartment, right side, position 3)

• Fuel filter OK

• Ignition switched off.

Voltage Supply, Checking

- Remove right side trim cover in luggage compartment (- arrows -).





- Up to model year XXX remove Fuse 10 on fuse holder SF10, as of model year 2004 remove Fuse 2 on fuse holder SF2 (in relay- and fuse holder, in luggage compartment, right side)

- Connect remote control (VAG1348/3A) with adapter cable (VAG1348/3-2) to right terminal of socket for Fuse 10 on fuse holder SF10-/Fuse 2 on fuse holder SF2(in relay- and fuse holder, in luggage compartment, right side).





- 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.

• Fuel Pump (FP) runs quietly. During test of Fuel Pump (FP), surrounding noise must be avoided; if necessary, use a second technician to check.

If no flowing noise can be heard:

- Remove luggage compartment floor lining.

- Remove cover for left connector flange (- arrows -).





- Carefully release and disconnect electrical harness connector - 2 - on left connector flange.





• Disregard - 1 -.

- 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 not obtained:

- Check fuse (in relay- and fuse holder, in luggage compartment, right side) according to wiring diagram or repair open circuit in wiring according to wiring diagram.

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

- Remove left fuel delivery unit.

- 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 faulty. Replace left fuel delivery unit, refer to Repair Manual.

- Install left fuel delivery unit.

Current Draw, Checking

Test Prerequisite

• Voltage supply of Fuel Pump (FP) OK =>

Right Fuel Delivery Unit with Transfer Fuel Pump, Electrical Testing.

- Up to model year XXX remove Fuse 10 on fuse holder SF10, as of model year 2004 remove Fuse 2 on fuse holder SF2 (in relay- and fuse holder, in luggage compartment, right side)

- Connect remote control (VAG1348/3A) with adapter cable (VAG1348/3-2) to right terminal of socket for Fuse 10 on fuse holder SF10-/Fuse 2 on fuse holder SF2 (in relay- and fuse holder, in luggage compartment, right side).





- Connect alligator clip to vehicle battery B+.

- Connect (VAS5051) tester with (VAS5051/9) inductive pick-up to wire of remote control.

- Press switch on remote control.

- Measure Fuel Pump (FP) current draw.

Specified value: approx. 8 amps

If specified value is not obtained:

• At a displayed current draw of 4 amps, Fuel Pump (FP) runs dry.