Blower Motor Control

The climate control system has a variable blower speed control provided by a brushless blower motor. The operator has the option of manually selecting one of eleven preset blower speeds from the control panel (seven preset blower speeds with telematics fitted) or selecting to operate the climate control assembly in automatic mode.

In automatic mode, the blower speed is determined as a function of many input variables. Based on the desired in-vehicle temperature, the system constantly monitors the ambient temperature, discharge air temperatures, in-vehicle temperature and sunload levels then calculates the desired blower setting.

There are special conditions that affect the blower speed while in the automatic mode of operation.

In a cold ambient temperature condition, the climate control assembly implements a Cold Engine Lock Out (CELO) feature with the blower motor. For a cold vehicle interior, the climate control assembly will operate in low blower/defrost mode until the engine coolant temperature reaches a required value. Once the engine coolant has warmed up the blower motor will continue in the automatic mode.

At very high vehicle speeds, monitored via the Standard Corporate Protocol (SCP) vehicle speed status message, the climate control assembly system may adjust the blower motor speed to maintain constant air flow. This may be necessary in situations where the ram air effects at high speed changes the air flow into the vehicle interior.

For vehicles fitted with a cellular phone, the climate control assembly may lower the blower motor speed to reduce the level of ambient noise in the vehicle interior when the phone is in use. The status of the cellular phone is monitored via the SCP cellular phone ON/OFF message.