Fuel Pump, Electrical Testing

Fuel Pump, Electrical Testing







Special tools and equipment
- Ring nut spanner 3217
- VAG1348/3-2 Adapter
- VAG1348/3A Adapter
- VAG1526A Multimeter
- VAG1594A Adapter kit

Requirements
- Battery voltage at least 12.7 V
- Fuse S228 OK (position 28)







- Relay 4 in micro-central electrics (in driver's footwell, left) OK
- Fuel filter OK
- Ignition switched off

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







- Connect VAG1348/3A remote control connection using adapter cables from VAG1348/3-2 at right terminal of socket from fuse - S228- (arrow).
- Connect clamping terminal to Battery +.
- Press switch of remote control.

Pump noise must be audible.

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

If no noise can be heard:

TT Coupe
- Remove rear seat bench.

TT Roadster
- Remove rear panel side trim.

Continued for all vehicles







- Unscrew cover -1- at right (arrows).







- Disengage 4-pin electrical harness connector and remove (arrow).







- Connect multimeter between terminal 1 and 4 of harness connector for voltage measurement.
- Press switch of remote control.

Specification: approx. battery voltage

If specified value is not obtained:
- Locate and repair open circuit using wiring diagram.

If specified value is obtained, although no operating noise can be heard from pump,remove connecting flange as follows:
- When removing the connection flange from the fuel pump, the fuel tank should be less than 1/3 full. If necessary, empty the fuel tank.
- Note radio code (for vehicles with coded anti-theft radio). Obtain if necessary.

Vehicles with 4-cylinder engine







- If installed, remove cover above battery.
- Open battery protective casing (Velcro).







- Switch ignition off and disconnect battery Ground (GND) strap (arrow).

Vehicles with 6-cylinder engine







- Switch ignition off and disconnect battery Ground (GND) strap (arrow) under trunk floor.

Continued for all vehicles

WARNING: Fuel supply lines are under pressure. Before removing from hose connection wrap a cloth around the connection. Then release pressure by carefully pulling hose off connection.







- Disconnect fuel supply line -1- and fuel return line -2- (press release button).

WARNING: Fuel tank must be less than 1/3 full when removing fuel pump. If necessary,empty fuel tank.







- Use ring nut spanner 3217 to remove and install
- Remove connecting flange of fuel pump via opening of fuel tank and lay aside with wires connected.
- Check whether electrical wires between flange and Fuel Pump (FP) are connected, check for continuity if necessary.

If no malfunctions are found in wires:
- Fuel Pump (FP) is faulty; replace fuel pump.