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Removing and installing fuel delivery unit - Vehicles with 4-cylinder engine (unit injector) > < Testing fuel pump relay -J17 and activation - Vehicles with 4-cylinder engine (unit injector)

A4 Mk1

Fuel supply system - Diesel engines
Fuel supply system - front-wheel drive
Testing fuel pump (electrical test) - Vehicles with 4-cylinder engine (unit injector)
 
G20-0016

Special tools and workshop equipment required

  • ◆ Ring nut spanner 3217
  • ◆ V.A.G 1275
  • ◆ V.A.G 1348/3A with V.A.G 1348/3-2
  • ◆ V.A.G 1526 A
  • ◆ V.A.G 1594 A

Requirements for test:
 
A97-0024
  • ● Battery voltage not less than 12.7 V
  • ● Fuse S228 OK
  • ● → Relay -J17 in 13-point relay carrier OK (no fixed position).
    Testing =>Page 20-37.
  • ● Fuel filter OK
  • ● Ignition switched off

Test sequence

  • ‒ Open fuse box cover on the left side of the dashboard panel.
  • ‒ Pull fuse S228 off fuse carrier (left row, 5th large fuse from the top).
 
A20-0098
  • ‒ → Connect remote control V.A.G 1348/3A with adapter cable V.A.G 1348/3-2 to right-hand terminal of fuse socket S228 -arrow-.
  • ‒ Connect clamp to vehicle battery (+).
  • ‒ Press remote control switch.
    • ‒ Pump should run (audible in boot - 2nd mechanic required).

If pump does not start running:

  • ‒ Detach floor trim in luggage compartment.
 
A20-0190
  • ‒ Unbolt cover for flange.
  • ‒ → Release and unplug connector -1-.
 
V96-0816
  • ‒ → Connect multimeter (voltage measurement range) between contact 1 (green/yellow) and contact 4 (brown).
  • ‒ Press and hold remote control switch, and read off voltage.
    • ‒ Specification: approx. battery voltage

If the specification is obtained, even though the fuel pump did not run, remove flange as follows:

Warning
  • ◆ In extreme cases the fuel pipes/hoses or the fuel can reach a temperature of 100 C on vehicles with unit injector engine. Allow the fuel to cool down before disconnecting the pipes/hoses - acute danger of scalding.

  • ◆ Wear protective gloves.
  • ◆ Wear protective goggles.
 
A20-0190
  • ‒ → Mark fuel return pipe -2- and fuel supply pipe -3- and disconnect from flange.
 
V20-1026
  • ‒ → Remove union nut with spanner 3217.
  • ‒ Remove flange and seal out of opening in fuel tank.
 
V20-1068
  • ‒ → Check that the electrical wires between flange and fuel pump are connected and test for continuity.

If no wiring fault is detected:

  • ‒ Fuel pump is defective. Renew fuel delivery unit =>Page 20-50.

Removing and installing fuel delivery unit - Vehicles with 4-cylinder engine (unit injector) > < Testing fuel pump relay -J17 and activation - Vehicles with 4-cylinder engine (unit injector)