Audi Workshop Service and Repair Manuals

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

• ‒ Switch ignition off.
• ‒ Remove connector from injection pump =>Fitting locations overview, page 23-4.

• ‒ → Connect multimeter for resistance measurement between the contacts on the sensor connector.

• Specified value: 90...120 ω (with a hot engine the resistance may be up to 20 ω higher)

If specified value is not attained:

• ‒ Replace cyl. 3 injector and needle lift sender (G80).

If specified value is attained:

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

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