Description And Operation: Operation

AUTOMATIC TEMPERATURE CONTROL (ATC) 

Each of the A/C heater controls in the ICS module are resistor type controls. When a button is pushed or a knob is turned, the ICS module sends a resistive signal over hardwired circuits to the Uconnect® touchscreen module. The controls in the Uconnect® touchscreen module mimic the action selected on the ICS module. The Uconnect® touchscreen module communicates the A/C heater control request signals to the Heating, Ventilation and Air Conditioning (HVAC) module.

The HVAC module is a dedicated microprocessor that automatically drives the electrically operated air-door actuators for the Dual Zone and Tri-Zone Automatic Temperature Control (ATC) HVAC systems. The ATC HVAC module obtains sun load, in-car temperature and evaporator temperature information through hardwired circuits, and occupant HVAC settings and other required vehicle information over the Controller Area Network (CAN) data bus.

The Dual Zone and Tri-Zone ATC HVAC systems are diagnosed using a scan tool. Refer to STANDARD PROCEDURE .

Prior to replacing an ICS module or HVAC module, check for any Diagnostic Trouble Codes (DTCs) related to the HVAC system and run the calibration procedure to verify that the concern is not an air-door calibration issue. Refer to DIAGNOSTIC CODE INDEX .

The individual A/C heater controls located in the ICS module cannot be adjusted or repaired. If an individual A/C heater control or control indicator lamp is inoperative or damaged, the entire ICS module must be replaced. Refer to MODULE, INTEGRATED CENTER STACK (ICSM), REMOVAL AND INSTALLATION .

The individual A/C heater controls located in the Uconnect® touchscreen module cannot be adjusted or repaired. If an individual A/C heater control or control indicator lamp is inoperative or damaged, the entire Uconnect® touchscreen module must be replaced.

MANUAL TEMPERATURE CONTROL (MTC) 

Each of the A/C heater controls in the ICS module are resistor type controls. When a button is pushed, or a knob is turned, the ICS module sends a resistive signal over hardwired circuits to the Uconnect® touchscreen module. The controls in the Uconnect® touchscreen module mimic the action selected on the ICS module. The Uconnect® touchscreen module communicates the heater and A/C control request signals to the HVAC module.

The HVAC module is a dedicated microprocessor for the Dual Zone and Tri-Zone Manual Temperature Control (MTC) HVAC systems. The MTC HVAC module obtains evaporator temperature information through hardwired circuits, occupant HVAC settings and other required vehicle information over the CAN data bus.

The Dual Zone and Tri-Zone MTC HVAC systems are diagnosed using a scan tool. Refer to STANDARD PROCEDURE .

Prior to replacing an ICS module or HVAC module, check for any Diagnostic Trouble Codes (DTCs) related to the HVAC system and run the calibration procedure to verify that the concern is not an air-door calibration issue. Refer to DIAGNOSTIC CODE INDEX .

The individual A/C heater controls located in the ICS module cannot be adjusted or repaired. If an individual A/C heater control or control indicator lamp is inoperative or damaged, the entire ICS module must be replaced. Refer to MODULE, INTEGRATED CENTER STACK (ICSM), REMOVAL AND INSTALLATION .