SRX AWD V6-3.0L (2010)
Seat Heater: Description and Operation
Rear Heated Seats
Rear Heated Seats Description and Operation
Heated Seat Components
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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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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20 A Fuse
Power and Grounds
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 G301.
Heated Seat Operation
The left and right rear heated seats are controlled by separate heated seat switches located in the rear seat audio module. The rear seat heating control
module controls the heated seat operation for both rear seats.
The left and right rear heated seats are controlled by a single seat heating control module that is located behind the rear seat back cushion. Both heated
seats are controlled by separate heated seat switches that are located in the rear seat audio module. When a heated seat switch is pressed, a GMLAN
message is sent from the rear seat audio module to the rear seat heating control module indicating the heated seat command. In response to this signal,
the rear seat heating control module then applies battery positive voltage through the element supply voltage circuit to the seat heating elements. The seat
heating control module then sends a serial data message back to the rear seat audio module to either illuminate or turn off the appropriate temperature
indicator.
Temperature Regulation
With the engine ON, the heated seats will initialize in the OFF state. With each activation of the heated seat switch, the rear seat heating control module
will cycle the temperature setting in the following manner: HIGH, MEDIUM, LOW, and OFF.
The rear seat heating control module monitors the seat temperature through the temperature sensor signal circuit and the temperature sensor (thermistor)
that is located in the seat cushion. The temperature sensor is a variable resistor, it's resistance changes as the temperature of the seat changes. When the
temperature sensor resistance indicates to the seat heating control module that the seat has reached the desired temperature, the module opens the ground
path of the seat heating elements through the heated seat element control circuit. The module will then cycle the element control circuit open and closed
in order to maintain the desired temperature.
Load Management
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 heated/cooled 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 (See: Starting and Charging/Description and
Operation/Electrical Power Management).