Air Temperature Control

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2012 Jaguar XFR, 2012 Jaguar XF, 2011 Jaguar XFR, 2011 Jaguar XF, and 2010 Jaguar XFR. However, it is still accessible from the selected car via links, so may be relevant.

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.

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 stepper motors, which are controlled by the automatic temperature control (ATC) module using local interconnect network (LIN) bus messages.

The automatic temperature control (ATC) module calculates the temperature blend stepper motor positions required to achieve the selected temperature and compares it against the current position. If there is any difference, the automatic temperature control (ATC) module signals the stepper 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 automatic temperature control (ATC) module adopts an appropriate strategy for air distribution, blower speed, and air source.

Temperature control in 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 (displayed as 'HI' or 'LO' on the TSD) can only be selected for the driver's side of the passenger compartment. If 'HI' or 'LO' is selected for the driver's side, the temperature for the front passenger's side is automatically set to match the driver's side.

If air conditioning (A/C) is selected off in the automatic mode, no cooling of the inlet 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 inlet path.

If the Temp. sync. soft button on the TSD is pressed, the automatic temperature control (ATC) module synchronizes the temperature of the passenger side of the passenger compartment with the driver's side.