Audi Workshop Service and Repair Manuals

The needle lift sender signal is used to determine the commencement of injection. If it fails the commencement of injection switches to open-loop control (according to engine speed and engine load). During normal operation the commencement of injection is controlled by a closed-loop function (according to engine speed, engine load and temperature).

• ‒ Switch off ignition.
• ‒ Disconnect connector for sender
  =>Fitting locations overview, Page 23-4.

• ‒ → Connect hand-held multimeter (resistance test range) between the contacts on the sender connector.

• Specification: 90...120ω (when the engine is hot the resistance may be up to 20 ω higher)

If the specification is not obtained:

• ‒ Replace cylinder 3 injector with needle lift sender (G80).

If the specification is obtained:

• ‒ Connect test box V.A.G 1598/31 to wiring harness for engine control unit. Do not connect to the engine control unit itself.
  .

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

• ‒ Rectify any open/short circuit as necessary.

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