Air Temperature Control

Cooled air from the evaporator enters the heater assembly, where temperature blend doors direct a proportion of the air through the heater core to produce the required output air temperature.

On vehicles with dual zone climate control, the two temperature blend doors operate independently to enable individual temperature settings for the left and right sides of the passenger compartment. The temperature blend doors are operated by electric motors, which are controlled by the ATCM using Local Interconnect Network (LIN) bus messages.

The ATCM calculates the temperature blend motor positions required to achieve the selected temperature and compares it against the current position. If there is any difference, the ATCM signals the motors to adopt the new position.

Air temperature is controlled automatically unless maximum heating (HI) or maximum cooling (LO) is selected. When maximum heating or cooling is selected, a comfort algorithm in the ATCM adopts an appropriate strategy for air distribution, blower speed, and air source.

On vehicles with dual zone climate control, temperature control of one side of the passenger compartment can be compromised by the other side of the passenger compartment being set to a high level of heating or cooling. True maximum heating or cooling can only be selected from the driver side temperature control switch. If HI or LO is selected from the driver side, the passenger side temperature will be automatically set to match the driver side. If the Sync soft key on the TS is selected, the ATCM synchronizes the passenger side settings with those of the driver side.

When air conditioning is selected off, no cooling of the intake air will take place. The minimum output air temperature from the system will be ambient air temperature plus any heat pick up in the air intake path.