A/C Control During Stop/Start Operation

During stop/start operation, A/C auto amp. changes air flow and control characteristics of air inlet within a range that does not adversely affect the comfort level, prolongs stop/start operation time and reduces power consumption for improving fuel economy. Refer to the following items for details of each control.

Air Flow Control 

Air flow reduction control during stop/start operation

• A/C auto amp. reduces duty ratio of blower motor control signal to blower motor to decrease air flow.
• Due to reduced air flow, the amount of air that passes evaporator is reduced to moderate increase of evaporator temperature. This helps prevent stop/start prohibition condition (evaporator temperature) from being met and prolongs stop/start operation time.
• Also, decrease of voltage applied to blower motor reduces power consumption. This moderates alternator power output after engine is restarted.

Air Inlet Control 

Air inlet change control during stop/start operation

• A/C auto amp. increases recirculation air mixing ratio compared to ordinary operation.
• By increasing recirculation air mixing ratio, cooled air in passenger room is circulated in larger amount than during ordinary operation and increase of evaporator temperature can be moderated. This helps prevent stop/start prohibition condition (evaporator temperature) from being met and prolongs stop/start operation time.