Audi Workshop Service and Repair Manuals

The throttle valve control part also incorporates the idling speed stabiliser.

The throttle valve potentiometer, idling speed switch, throttle valve positioner and potentiometer for throttle valve positioner are located inside the housing opposite the cable pulley.

The housing must not be opened. This means that the two potentiometers, the idling speed switch and the throttle valve positioner cannot be adjusted manually or replaced.

All adjustments are made via the "Basic setting" function on the V.A.G 1551.

When there is no electrical signal the throttle valve is moved mechanically to a pre-determined position, which causes the engine to idle at a higher speed when warm.

The throttle valve positioner is responsible for damping the action of the throttle valve as it closes.

The angle to which the throttle valve positioner can open the throttle valve is limited, i.e. it cannot open it to full throttle (for example).