Audi Workshop Service and Repair Manuals

Electrical checks on injectors

• ‒ Start final control diagnosis and actuate injectors .

• ‒ Turn the throttle mechanism on the throttle valve control unit to open the idling switch.

• The injector should click five times.

If the injector clicks:

• ‒ Activate the next injector.

If the injector does not click:

• ‒ Remove connector from the injector which is to be tested.
• ‒ → Connect the V.A.G 1527 diode test lamp between contact 1 and contact 2 in the connector.
• ‒ Repeat the final control diagnosis and again actuate the injector.

• The diode test lamp should flash five times.

Note:

Diode test lamps with a low current consumption do not go out completely between the flashing pulses, but continue to glow slightly and become much brighter during the flashing pulses.

If the diode test lamp does not flash:

• ‒ Check the voltage supply
  => Page 24-27.

If the diode test lamp flashes:

• ‒ → Connect multimeter to valve to measure resistance

• Specification: 11...13 ω

If the specification is not obtained:

• ‒ Renew injector.

Checking power supply

• ‒ Remove connector from the injector which is to be tested.
• ‒ → Connect the multimeter (voltage measurement range) to contact 1 on the connector and to earth.
• ‒ Operate starter for a few seconds (the engine can be allowed to start).

• Specification: The diode test lamp should light up.

If the diode test lamp lights up:

• ‒ Check wiring => Page 24-28

If the diode test lamp does not light up:

• ‒ → Check wiring connection from Contact 1 to the fuse for injector.

=> "Current Flow Diagrams, Electrical Fault Finding and Fitting Locations" binder

Checking wiring

• ‒ Switch off ignition.
• ‒ Remove connector from the injector which is to be tested.
• ‒ Connect test box V.A.G 1598/22 to wiring harness for engine control unit
  => Page 24-6.

The following wiring connections should be checked for open circuits and/or short to positive or negative.

• ‒ Rectify any open/short circuit as necessary.