The driver, front passenger, and second row passenger heat/cool seat system consists of the following components:

Each of the heated/cooled seats consist of the following components:

The heat/cool seat system operating modes are as follows:

Pressing the heat or cool switches will activate the system to the back and cushion high heat or high cool modes only. After a seat has been turned on in the heat or cool modes pressing the seat cushion or seat back switches will reduce the temperature setting one level from high to medium, low, and off. The seat back only will operate in the heat modes only and when attempting to operate the seat back only in the cool mode the seat back indicator will flash for several seconds and the system will default to the back and cushion mode.

The heat/cool seat system functions independently of the memory seat system and none of it's components communicate over the class 2 serial data circuit. The heat/cool seat switch assemblies are supplied with ignition voltage, ground, and illumination circuits. The switch assemblies interface with the signal converter through the switch signal and the indicator control circuits. The heat/cool seat switches are 12-volt inputs to the signal converter which processes the multiple switch inputs from each of the seat switch assemblies and converts them to 4 pulse width modulation (PWM) mode signal circuits, one for each of the heated/cooled seat assemblies. Besides suppling the climate control seat modules with PWM mode signal circuits, the signal converter also uses the processed switch inputs to control the switch indicator LEDs through the indicator control circuits. The PWM mode signal circuits are referenced from battery voltage within the climate control seat modules and the PWM duty cycle is determined by the frequency that the signal converter drives the circuit low.

Each heated/cooled seat is controlled by a climate control seat module (CCSM) located under the seat cushion. The CCSM is supplied with battery voltage, ignition voltage, ground, and a mode signal circuit. All heat/cool seat modes will operate with the ignition on without the engine running, although due to the high current draw inconsistent operation could occur. When verifying a customer concern doing so with a fully charged battery and the engine running will provide the most consistent results. The CCSM controls heat/cool seat ventilation blowers located under the seat cushion and behind the seat back. The ventilation blowers are self contained electronic air conditioners consisting of a blower motor with an inlet air filter, thermal electric device (TED), temperature sensor, and waste air duct. The air flow from the blower is divided into 2 streams and directed across both sides of the TED, one side into vent passages through the seat foam and the other out the waste air duct. While the system is operating in either the heat or cool modes both heated and cooled air is generated as it passes across the TED. When voltage is applied to a TED, one side releases energy as heat, while the opposite side absorbs energy and gets cold. The supply voltage to the TEDs is controlled by the CCSM and the polarity determines which side gets hot or cool. When the polarity of the current flow to the TEDs is switched, the hot and cool sides of the TED reverse. The CCSM monitors the temperature of the air flow into the seat foam and continuously adjusts the blower speed and TED temperature by regulating the current flow through each component. The CCSMs rely on inputs from temperature sensors located in the ventilation blowers near the TEDs to control seat temperatures. The thermistors are 2 wire sensors supplied with a 5-volt referenced signal circuit and a low reference circuit from the CCSM. Resistance through the thermistors varies with temperature causing the heated seat sensor signal circuit voltage levels to decrease as the TED temperatures rise.