Audi Workshop Service and Repair Manuals

A - Electrical testing of injectors

• ‒ Remove plug connector from the injector which is to be tested.
• ‒ → Measure resistance between the injector contacts using V.A.G 1526.

Specification: 13...18 ω.

When the engine is warm the resistance will be approx. 4...6 ωhigher.

• ‒ If the measured value is not as specified, renew the injector.

B - Testing power supply

Test conditions

• ● Fuse for injectors OK

• ‒ Remove plug connector from the injector which is to be tested.
• ‒ → Connect diode test lamp V.A.G 1527 between contact 1 and engine earth.
• ‒ Operate starter for a few seconds (the engine can be allowed to start). The diode test lamp should light up.

• ‒ If the diode test lamp does not light up, test for open circuits in the wiring between contact 1 and the fuse for the injectors.

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

• ‒ If the diode test lamp lights up, test activation of injectors.

C - Testing activation of injectors

• ‒ Remove plug connector from the injector which is to be tested.
• ‒ → Connect diode test lamp V.A.G 1527 between contact 2 and positive terminal of battery.
• ‒ Operate starter for a few seconds (the engine can be allowed to start).

Specification: the diode test lamp should start flashing.

Note:

Diode test lamps with a low current draw continue to glow faintly between flashes (rather than going out completely) and become much brighter during the flashes.

• ‒ If the diode test lamp does not start flashing:
• ‒ Connect test box V.A.G 1598/22 to wiring harness for engine control unit
  .
• ‒ → Test for short circuits or open circuits in the wiring between the engine control unit and contact 2 on the plug connector for the injector being tested

• ‒ Rectify short circuit or open circuit if necessary.
• ‒ If the wiring is OK, fit a new engine control unit
  => Page 24-10.