A3 1.6 l - fluctuating idle speed you will require vag com for this and lalso clean out the throttle body before you do this and adapt the throttle body basic setting channel 60 or 98
Problem description
Engine surges when idling, engine speed fluctuates and drops sporadically.
Cause
A specified engine speed of 680 rpm, the desired load recognition through turning the steering to full lock and the recognition of consumers by the alternator, can result in slight engine speed fluctuations.
If basic setting of the throttle valve control unit has not been successful, the idling speed can be increased by approx. 50 rpm. This adaptation is performed in the engine control unit and only functions with the ignition switched on.
Call up engine control unit with 01,
then call up adaptation with 10,
enter channel 01 and confirm.
The line at the top right must show 128 (corresponds to 680 rpm); the new idling speed can be entered in the bottom line in steps of 10 rpm. (129 = 690 rpm ..... 130 = 700 rpm).
In order to return to the original setting, 128 must again be entered