Adaptive Vacuum Switch (AVS)

The AVS is located inside engine compartment on right inside fender panel. This switch is closed during engine idle and partial throttle engine operation. During partial throttle operation (adaptive operation mode), the M/C solenoid is regulated to produce predetermined air/fuel mixture ratios. During acceleration from idle to partial throttle and deceleration from partial throttle to idle, oxygen sensor cannot react fast enough to changes in air/fuel mixture. As a consequence, high HC and CO exhaust gases would be emitted momentarily unless the system switched to pre-determined air/fuel mixture ratios.