Audi Workshop Service and Repair Manuals

Special tools and workshop equipment required

• ◆ V.A.G 1526 A
• ◆ V.A.G 1527 B
• ◆ V.A.G 1594 A
• ◆ V.A.G 1598/31

Test requirement:

• ● Battery voltage not less than 12.7 V

Test sequence

• ‒ Remove storage compartment on driver's side:

=> General body repairs, Interior; Repair group 68; Storage compartments, covers; Removing driver's storage compartment

• ‒ Operate starter.

• ‒ → The fuel pump relay in 13-point relay carrier should pick up (no fixed position); this can be felt by touching the relay. The fuel pump should run (audible in boot - 2nd mechanic required).

A - If the relay does not pick up:

• ‒ Test voltage supply to fuel pump relay.
• ‒ Test activation of fuel pump relay
  =>Page 20-42.

B - If the relay picks up but the fuel pump does not run:

• ‒ Test activation of fuel pump
  =>Page 20-44.
• ‒ Test fuel pump (electrical test) =>Page 20-45.

Testing voltage supply of fuel pump relay

• ‒ → Remove fuel pump relay from 13-point relay carrier (no fixed position).

• ‒ → Connect voltage tester V.A.G 1527 B as follows:

• ‒ Switch on ignition.
• ‒ The LED should light up.

If the LED does not light up:

• ‒ Switch off ignition.
• ‒ → Remove rubber seal from plenum chamber in direction of arrow-.
• ‒ Remove plenum chamber cover -1- from the front.

• ‒ → Remove cover for electronics box in plenum chamber -arrows-.

• ‒ → Unplug terminal 30 voltage supply relay -J317 (located in 3-point relay carrier in electronics box, plug-in position 3.
• ‒ Test for open circuit and short to positive or earth in the following wiring connection:

• ‒ Rectify any open/short circuit as necessary.

=> Current flow diagrams, Electrical fault finding and Fitting locations binder

If no wiring fault is detected:

• ‒ Test voltage supply of diesel direct-injection system:

=> TDI diesel direct injection and glow plug system (4-cylinder unit injector); Repair group 23; Servicing diesel direct injection system; Testing voltage supply of diesel direct injection system

Testing activation of fuel pump relay

• ‒ → Carefully lever off the retainer bar with a screwdriver -arrow-.

• ‒ → Release retainer catch -arrows- and unplug connectors -1- and -2- from control unit.
• ‒ Take out engine control unit.

• ‒ → Connect test box V.A.G 1598/31 to the connectors which have been unplugged from the engine control unit (control unit remains disconnected). Also connect earth clamp on test box to earth.

• ‒ → Test for open circuit and short to positive or earth in the following wiring connections:

• ‒ Rectify any open/short circuit as necessary.

=> Current flow diagrams, Electrical fault finding and Fitting locations binder

Testing activation of fuel pump

Requirements for test:

• ● Fuel pump relay connected
• ● Engine control unit connected.

• ‒ Open fuse box cover on the left side of the dashboard panel.

• ‒ → Pull fuse S 228 off fuse carrier (left row, 5th large fuse from the top).
• ‒ Connect multimeter (voltage test range) between earth and left fuse contact.
• ‒ Operate starter.
• ‒ Specification: approx. battery voltage

If the specification is not obtained:

• ‒ Check wiring

=> Current flow diagrams, Electrical fault finding and Fitting locations binder

If the wiring is OK and no faults are found in the tests up to this point:

• ‒ Fit a new fuel pump relay -J17.