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.
Front Seat Riser Finish Cover Replacement
Front Seat Riser Finish Cover Replacement
Callout
Component Name
1
Front Seat Riser Finish Cover
Caution: Do not ...
Rear Seat Head Restraint Guide Replacement
Rear Seat Head Restraint Guide Replacement
Callout
Component Name
Preliminary Procedure
Remove the rear seat head restraint. Re ...
Other materials:
Rear Window Wiper Motor Grommet Replacement
Rear Window Wiper Motor Grommet Replacement
Callout
Component Name
Preliminary Procedure
Remove the rear window wiper motor. Refer to Rear Window Wiper Motor
Replacement.
1
Rear Window Wiper Mot ...
Steering Knuckle Replacement
Removal Procedure
Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
Remove the tire and wheel assembly. Refer to Tire and Wheel Removal
and Installation.
Remove the wheel speed sensor from the steering knuckle. Refer to Front
Wheel Speed Sensor ...
Timing Chain Tensioner Replacement
Timing Chain Tensioner Replacement
Callout
Component Name
Preliminary Procedure
Remove the camshaft timing chain . Refer to Camshaft Timing Chain Replacement.
1
Timing Chain Tensioner Fastener (Q ...
0.0098