Audi Workshop Service and Repair Manuals

A - Electrical testing of injectors

• ‒ Remove connector from the injector which is to be tested.
• ‒ → Measure resistance between the injector contacts using V.A.G 1526.
  Engine cooled down to room temperature.
  Specified value for engine code ADP: 14...16 ohm
  engine code ADR: 11...13 ohm
  engine code AEB: 11...13 ohm
  When the engine is at operating temperature, the resistance is increased by approx. 4...6 ohm.
• ‒ If the measured value is not as specified, renew the injector. Removing and installing injectors =>Page 24-26.

B - Testing power supply

Test requirements:

• ◆ Fuse -S34 for injectors OK.

• ‒ Remove connector from the injector which is to be tested.
• ‒ → Connect diode test lamp V.A.G 1527 between engine earth and contact 1.
• ‒ 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 continuity in circuit from contact 1 via the fuse for the injectors -S34 to the fuel pump relay according to the current flow diagram - if necessary rectify open circuit.
• ‒ If the diode test lamp lights up, test actuation of injectors.

C - Testing activation of injectors

• ‒ Remove connector from the injector which is to be tested.
• ‒ → Connect diode test lamp V.A.G 1527 between contacts 1 and 2.
• ‒ Operate starter for a few seconds (the engine can be allowed to start) - the diode test lamp must flash.

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, connect test box V.A.G1598/19 to the wiring harness for Motronic control unit -J220.
• ‒ → Test for open circuit or short to positive in the wiring between the Motronic control unit and contact 2 on the plug connector for the injector being tested.

• ‒ Rectify any open/short circuit as necessary.
• ‒ If the wiring is OK, replace the Motronic control unit.