Diagnostics of the actuator (Audi A4 B5)

Decisive for a smooth repair is also the additional function of the fault reader, which Audi calls the actuator. This means the following: electrical functions – such as actuating the fuel pump relay, the carbon canister solenoid valve or the idle speed control valve – are also activated by the fault reader.

In this way, it is possible to find out in principle whether there is a defect in the wires and whether the device itself has been repaired (most often, the work is heard in the absence of engine noise).

[This publication is borrowed from the resource: AUDIMANUAL]