Chevrolet Sonic Repair Manual: Heated Seats Description and Operation
- Heated Seat Components
-
The driver and passenger heated seats each consist of the following components:
- Left heated seat switch
- Right heated seat switch
- HVAC control module
- Seat heating control module
- Seat cushion heating element
- Seat back heating element
- Seat cushion temperature sensor
Note:
The passenger seat block diagram is identical to the driver seat.
- Heated Seat Block Diagram
K29 Seat Heating Control Module E14C Seat Heating Element - Passenger Back E14D Seat Heating Element - Passenger Cushion E14A Seat Heating Element - Driver Back E14B Seat Heating Element - Driver Cushion K33 HVAC Control Module
- Heated Seat Operation
-
The driver and passenger heated seats are controlled by a single seat heating control module that is located under the driver seat cushion. Both heated seats are controlled by separate heated seat switches that are located in the HVAC control. When a heated seat switch is pressed, a serial data message is sent from the HVAC control to the HVAC control module indicating the heated seat command. The HVAC control module then serves as a gateway to transmit the message to the seat heating control module via the serial data line. In response to this signal, the seat heating control module applies battery positive voltage through the element supply voltage circuit to the appropriate seat heating elements. The seat heating control module then sends a serial data message back to the HVAC control module to gateway the information to the HVAC control to either illuminate or turn off the appropriate temperature indicator.
- Temperature Regulation
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When the engine ON, the heated seats will initialize in the OFF state. With each activation of the heated seat switch, the seat heating control module will cycle ON and OFF.
The 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 Shed Management
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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 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.
Heated Seat Control Module Programming and Setup
The seat heating control module must be programmed with the proper calibration
software. The module stores and utilizes this information however if it is not properly
configured with the correct c ...
Seats
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Other materials:
Special Tools
Illustration
Tool Number/ Description
EN-45059
J-45059
Angle Meter
...
Front Side Door Weatherstrip Replacement - Body Side
Front Side Door Weatherstrip Replacement - Body Side
Callout
Component Name
Preliminary Procedures
Remove the upper center pillar trim. Refer to Center Pillar Upper
Trim Panel Replacement.
Remove the lower center pillar t ...
Toe Description
Toe is a measurement of how much the front and/or rear wheels are turned in or
out from a straight-ahead position. When the wheels are turned in, toe is positive (+).
When the wheels are turned out, toe is negative (−). The actual amount of toe is
normally only a fraction ...
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