LR3/Disco 3
GENERAL
The control system operates the Air Conditioning (A/C) system and the heating and ventilation system to control the
temperature, volume and distribution of air from the heater.
Either a manual or an automatic control system is installed in the vehicle. The manual system maintains a constant heater
outlet temperature, to both sides of the passenger compartment, with manual control of the intake air source, blower
speed and air distribution. The automatic system automatically adjusts the temperature, volume and distribution of the air
from the heater to maintain the individual temperature levels selected for the LH and RH sides of the passenger
compartment. The automatic system also has manual overrides for the intake air source, blower speed and air
distribution. The manual and automatic systems both include:
An Automatic Temperature Control Module (ATCM).
An ambient temperature sensor.
A refrigerant pressure sensor.
An evaporator temperature sensor.
The automatic system incorporates the following additional components:
An in-vehicle temperature sensor.
A sunlight sensor.
The automatic system in the Japan market also incorporates:
A pollution sensor.
A humidity sensor.
ATCM
The ATCM is installed in the center console. An integral control panel contains push switches and rotary switches for
system control inputs. LED's in the switches and switch surrounds illuminate to indicate the current settings of the system.
Switch symbols are illuminated when the side lamps or headlamps are on.
The ATCM processes inputs from the control panel switches, system sensors and the medium speed Controller AREA
Network (CAN) bus, then outputs the appropriate control signals to the A/C system and the heating and ventilation
system. In addition to controlling the A/C system and the heating and ventilation system, the ATCM also controls the
following:
The front seat heaters. For additional information, refer to
Seats
(501-10 Seating)
The rear window heater. For additional information, refer to
Glass, Frames and Mechanisms
(501-11 Glass,
Frames and Mechanisms)
The windshield heater. For additional information, refer to
Glass, Frames and Mechanisms
(501-11 Glass,
Frames and Mechanisms)
The windshield washer jet and exterior mirror heaters. For additional information, refer to
Rear View Mirrors
(501-
09 Rear View Mirrors)
Manual System Control Panel
5
-
In-vehicle temperature sensor; In-vehicle temperature and humidity sensor (Japan only)
6
-
Refrigerant pressure sensor
7
-
Ambient air temperature sensor
