Secondary Throttle Valve: Description and Operation

ADS II Throttle Body:

DESCRIPTION
The Auxiliary Throttle Valve (ADS II), or Choke Unit, is mounted between the primary throttle body and the mass air flow sensor. In the event of rear wheel spin, due to excessive acceleration, the throttle plate is pulled closed by the ADS 11 control module reducing engine power output. The ADS 11 throttle plate is held open by spring pressure and houses a potentiometer for throttle valve position sensing.