Audi Workshop Service and Repair Manuals

Note:

• ◆ The engine speed sender is a combined speed sender and reference mark sender. Without a signal from the -G28 the engine cannot be started. If the signal from the -G28 fails while the engine is running, the engine will cut out immediately.
• ◆ For testing the operation of the engine speed sender, see also "Reading measured value block", Display Group 03, display zone 1.

Testing engine speed sender

Fitting location of sender and connector
=> Page .

• ‒ Before carrying out the test, make sure that the sender is correctly installed and firmly seated.
• ‒ Unplug connector from engine speed sender (grey connector).

• ‒ → Connect hand-held multimeter V.A.G 1526 (resistance test range) to contacts 2 and 3 on connector in connector support bracket using test lead from V.A.G 1594.

Specification: approx. 450...1000 ω

• ‒ If the value does not match the specification, fit a new engine speed sender.
• ‒ If the value does match the specification, connect hand-held multimeter to contacts 2 and 1 (earth) and to contacts 3 and 1 (earth).

Specification:∞ω (open circuit) in each test

• ‒ If the value does not match the specification, fit a new engine speed sender.
• ‒ If the value does match the specification,test the wiring between the sender connector and the engine control unit as follows:

• ‒ Connect test box V.A.G 1598/22 to wiring harness for engine control unit
  .
• ‒ → Test continuity of screening from contact 1 on sender connector to socket 67 on test box.

Specification: max. 1 ω.

• ‒ Test continuity of earth wire from contact 2 on sender connector to socket 63 on test box.

Specification: max. 1 ω.

• ‒ Test continuity of signal wire from contact 3 on sender connector to socket 56 on test box.

Specification: max. 1 ω.

• ‒ If the values do not match the specifications, rectify short circuits or open circuits between sender connector and connectors on engine control unit.

• ‒ If no open circuits or short circuits are found, fit a new engine control unit .