Rear Heated Seats Description and Operation
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Rear Heated Seats Description and Operation
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The rear heated seat system has one control module that controls heat operation for both the left and right rear seat. The rear heated seat system consists of the following components:
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Rear seat heating control module
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Rear audio control module
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Left rear heated seat switch
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Right rear heated seat switch
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Left seat cushion heating element
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Left seat back heating element
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Left seat cushion temperature sensor
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Right seat cushion heating element
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Right seat back heating element
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Right seat cushion temperature sensor
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Battery positive voltage is supplied to the rear seat heating control module through a 20 A fuse that is located in the rear fuse block. This voltage is used to power up the rear sear heating control module and to supply power to the seat heater elements. Ground for the rear seat heating control module is provided at G401.
The heated seat system is designed to operate with the engine ON. The left and right rear heated seat switches are located in the face plate of the rear audio control module. The rear seat heating control module located under the seat cushion (40 % side), controls the heated seat operation for both rear seats. When a heated seat switch is pressed, a serial data message is sent from the rear audio control module to the rear seat heating control module indicating the heated seat command. In response to this message, the rear seat heating control module applies battery positive voltage through the heater element supply voltage circuit and ground through the low side control circuit to the seat heating elements. The seat heating control module then sends a serial data message back to the rear audio control module to illuminate the appropriate seat temperature indicator.
The heated seat system is designed to warm the seat cushion and seat back to three different temperature settings: High, Medium and Low. The rear seat heating control module supplies the seat temperature sensor with a 5 V reference signal circuit and a the low reference circuit. The temperature sensor (thermistor) is located just under the seat cushion cover with the heater element. The sensor is a variable resistor; its resistance changes as the seat temperature changes causing the voltage on the signal circuit to change. The module monitors this voltage to determine the temperature of the seat. Once the seat reaches the set temperature, the module will then cycle the low side control circuit of the heating elements ON and OFF in order to maintain the desired temperature.
The electrical power management function is designed to monitor the vehicle electrical load and determine when the battery is potentially in a high discharge condition. The rear heated seat system is one of the vehicle loads that is subject to reduction during a battery discharge condition. For more information on load management refer to
Electrical Power Management Description and Operation
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