Secondary Throttle Fully-closed Position Self-learning Control
When a certain condition occurs with ignition switch ON, the TAC module checks for operation of the throttle control system. It does this by fully closing the secondary throttle and then opening it fully. Simultaneously, the TAC module reads the secondary throttle position sensor output values at both the fully closed/opened positions. This data is used for self-diagnosing the secondary throttle driving system. The same data is also used for improving the control accuracy of the secondary throttle.
This learning control is performed at the moment the ignition switch is turned ON under conditions: Automatic transmission is set in "N" or "P" position; Accelerator pedal is released completely.