Audi Workshop Service and Repair Manuals

Checking fuel pump (electrical test)

Special tools and workshop equipment required

t	Remote control -V.A.G 1348/3A- for V.A.G 1348 with adapter cable -V.A.G 1348/3-3-

t	Hand-held multimeter -V.A.G 1526C-

t	Auxiliary measuring set -V.A.G 1594C-

Procedure l  Battery voltage at least 12.5 V l  Fuse in fuse holder -S228- (position 28) OK.

l  Vehicles with MPI engine: Fuel pump relay -J17--arrow- OK (located at plug-in position No. 1 in nine-way relay carrier behind storage compartment on driver's side).

l  Vehicles with 4-cylinder TFSI engine: Fuel pump control unit -J538- must be OK; checking → Chapter. l  Fuel filter OK l  Ignition off. Saloon: –  Detach trim in luggage compartment. –  If necessary, fold forward right backrest of rear seat bench. Avant: –  Remove left-side section of backrest (1/3 section) → Rep. Gr.72. –  Remove left-side trim in luggage compartment and anti-soiling tray → Rep. Gr.70.

All models: –  Unscrew cover for flange -arrows-.

–  Unplug electrical connector -arrow- at flange.

–  Connect remote control -V.A.G 1348/3 A- with adapter cable -V.A.G 1348/3-3- to contact -1- using a test lead from auxiliary measuring set -V.A.G 1594C-. –  Tape off 2nd connector contact of the adapter cable -V.A.G 1348/3-3- with insulating tape -arrow- to prevent short circuits. –  Connect contact -4- to the body (earth) using a test lead from auxiliary measuring set -V.A.G 1594C-. –  Connect crocodile clip to positive (+) terminal of battery. –  Press remote control button. l  Pump should start running audibly.   Note The fuel pump runs very quietly. Where possible, avoid noisy surroundings for this test.

If no noise can be heard from pump: –  Remove fuel delivery unit → Chapter. –  Check that the electrical wires between flange and fuel pump are connected and test for continuity. If no fault is found in wiring, fuel pump is defective. Renew fuel delivery unit. –  Install fuel delivery unit → Anchor.