The driver and passenger climate control seat systems each consist of the following components:

Both the driver and passenger seat have independent CCS systems. A CCSM mounted to the bottom of each seat cushion electronically controls each CCS system. The CCSM receive power from both battery positive voltage and ignition 1 voltage. The ignition must be in the ON position with the heated/cooled seat switch set in the HEAT or COOL position for CCS system to activate.

Once a CCS system is activated, cabin air is drawn through the blower motor and distributed to each of the heated/cool seat ventilation modules located under the seat cushion and in the seat backrest. The copper fins on the ventilation modules then heat or cool the passing air. The conditioned air is then directed into the bottom of the foam pad and along the surface of the seat to the occupant. The CCSM uses a set of algorithms to control the temperature of the heating/cooling modes.

The driver and passenger climate control seats can be operated independently of one another, and each is activated by a separate heated/cooled seat switch. Both switches are located in the HVAC control module. When a switch is pressed once, the HVAC module illuminates the HI HEAT temperature indicator and sends a pulse width modulated signal to the CCSM. The CCSM then turns on the seat temperature to high heat in response to the switch signal. When the switch is pressed a second time, the HVAC module illuminates the LO HEAT temperature indicator and sends a signal to the CCSM indicating the low heat request. When the switch is pressed a third time, the HVAC module will turn off the temperature indicator and signal the CCSM to turn off the system. If, after a slight pause, the switch is pressed a fourth time, the HVAC module illuminates the HI COOL temperature indicator and sends a signal to the CCSM indicating the high cool request. When the switch is pressed a fifth time, the HVAC module illuminates the LO COOL temperature indicator and sends a signal to the CCSM indicating the low cool temperature request. When the switch is pressed a sixth time, the HVAC module will turn off the temperature indicator and signal the CCSM to turn off the system.

Battery positive voltage is supplied at all times to each CCSM through the battery positive voltage circuit and the HTD SEAT LH Fuse and the HTD SEAT RH Fuse located in the IP fuse block. This voltage is used by each module to supply power to the ventilation modules and the blower motor. Battery positive voltage is also supplied to each module through the ignition 1 voltage circuit and the RPA / H/C SEAT Fuse 11 located in the body control module (BCM). The RPA / H/C SEAT voltage is used to power up each module and allows the CCS system to operate only with the ignition in the ON position. Each CCSM is grounded through the module ground circuit to the ground stake.

Each heated/cooled seat has two heated/cooled seat ventilation modules, which are Thermo-Electronic Devices (TEDs), mounted downstream of the blower motor. These modules are controlled by the CCSM. Each ventilation module consists of a circuit of positive and negative connections sandwiched between two ceramic plates. Each ceramic plate is equipped with copper fins for heat exchange. The air flowing past these fins is either directed as conditioned air to the seat cushion and seat back, or directed to the cabin as waste air.

The ventilation module is essentially a solid state heat pump that is used to heat or cool the air supply to the seat cushion and seat back. When voltage is applied to the ventilation module, one side of the module releases energy as heat, while the opposite side absorbs energy and gets cool. When the polarity of the current flow is switched, the hot and cool sides reverse.

The seat temperature sensors are thermistors which are attached directly to the fins of each ventilation module. The CCSM supplies a 5 volt reference voltage through the temperature sensor signal circuit and ground through the temperature sensor low reference circuit to the respective seat cushion and seat back temperature sensors. As the temperature of the ventilation module changes, the resistance of the thermistor varies changing the feedback voltage of the temperature sensor signal circuit. This voltage varies from 0.5 volts to 4.0 volts. The CCSM monitors this voltage signal to determine the fin temperature so that it can adjust the seat temperature to the selected switch input.

When the heated/cooled seat switch is pressed for HI Heat, the Temperature Set Point, the CCSM will transition to the HEAT state. In the heat state, the module applies a pre-determined voltage through the heat control circuit to the ventilation module while providing a ground through the cool control circuit to the ventilation module. A pre-determined voltage is also applied through the blower speed control circuit to the blower motor. The CCSM uses the following sequence, beginning with the Heat SoftStart Mode, to achieve the Set Point Temperature before it can enter the Control Heat Mode. If the fin temperature is already above the Temperature Set Point, the CCSM will skip the Heat SoftStart Mode and proceed to the Control Heat Mode.

When the heated/cooled seat switch is pressed for HI Cool, the CCSM will transition to the COOL state. In response to this command, the module applies a pre-determined voltage through the cool control circuit to the ventilation module while providing a ground through the heat control circuit to the ventilation module. A pre-determined voltage is also applied to the blower motor. The CCSM uses the following sequence, beginning with the Cool SoftStart Mode, to achieve the Set Point Temperature before it can enter the Control Cool Mode.