Control Components

Dual Automatic Temp. Control (DATC) Components:

The Dual Automatic Temperature Control (DATC) electrical control module is a single module packaged in the centre stack of the vehicle. It is a microprocessor-based control consisting of a bezel assembly (including all buttons and switches), a main control board and a housing for the unit.

The DATC module provides the following driver interface controls:
- 1 AUTO mode button
- 5 mode buttons (including defrost) for manual discharge air selection
- 1 OFF button
- 1 EXT button for displaying external temperature
- 1 RECIRCULATE AIR select button
- 1 A/C button for manual A/C selection
- heated rear window on/off control
- heated front wiper rest or heated front windscreen on/off control
- 2 vertical rocker switches for temperature adjustment (driver/passenger)
- 1 vertical rocker for manual speed selection
- 1 English/metric select button

Operating any of the DATC controls activates a chime emitted from the instrument cluster.

The DATC automatically maintains a selected temperature for the interior of the vehicle. The system regulates the volume of airflow between the instrument panel registers, rear seat panel registers, front and rear floor ducts, windshield defroster and side window demisters. The system can automatically select between fresh and recirculated air with an optional manual override. The DATC will try to provide both the driver and the passenger with their selected temperature for comfort. The fan controls and air distribution are not controlled individually.

Blower Motor Control
The climate control system has a variable blower speed control provided by a Variable Blower Control (VBC) module with an integral high blower relay. The customer has the option of manually selecting one of seven preset blower speeds from the control panel or selecting to operate the DATC 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 sun load 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 DATC system implements a Cold EngineLockout (CELO) feature with the blower motor. For a cold vehicle interior, the DATC system 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 SCP Vehicle speed status message), the DATC 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 DATC module 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 or OFF message.

Air Distribution Control
The climate control system has variable position control provided by the electrical motor actuators. The system gives the option of manually selecting one of five preset air distribution modes or operating the DATC system in automatic mode.