Audi Workshop Service and Repair Manuals

The engine speed signal is required for the rev counter, air conditioner and automatic gearbox.

However, since the signal cannot be read in the form in which it is generated by the engine speed sender (G28), it has to be processed by the engine control unit.

Identify the engine speed signal as follows:

Dash panel insert

• ‒ Observe rev counter reading.

• Specification: The current engine speed should be displayed.

Air conditioner

The signal is monitored by the air conditioner self diagnosis function (fault memory, read measured value block).

Signal testing

=> Heating, Air conditioning; Repair Group 01

• Specification: The current engine speed should be displayed in the measured values block.

Automatic gearbox

The signal is monitored by the self diagnosis (fault memory, read measured value block) of the automatic gearbox control unit.

Signal testing

=> Automatic gearbox; Repair Group 01

• Specification: The current engine speed should be displayed in the measured values block.

If the engine speed signal specified values is not achieved for all "consumers", the following faults are possible:

• ◆ Open circuit or short circuit between engine control unit and harness connector.

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

• ◆ Short circuit between connector in harness and "consumer".
• ◆ Engine control unit defective.

If the engine speed signal specified value is achieved for at least one "consumer", the following faults are possible:

• ◆ Open circuit in wiring between wiring harness connector and "Consumer"
• ◆ "Consumer" defective.