Chevrolet Equinox Service Manual: Heated Seats Description and Operation (Factory Installed) Seats

Heated Seat Components

The heated seat system consists of the following components:

Heated seat switchRadio/HVAC controlsSeat memory control module or seat heating control moduleSeat cushion heating elementSeat back heating elementSeat cushion temperature sensor

Note:The passenger seat block diagram is identical to the driver seat.

Heated Seat Block Diagram

(A45)(KA1)A20Radio/HVAC ControlsK29Seat Heating Control ModuleE14CSeat Heating Element - Passenger BackE14DSeat Heating Element - Passenger CushionE14ASeat Heating Element - Driver BackE14BSeat Heating Element - Driver CushionK40Seat Memory Control ModuleSerial Data

Hard-Wired

MEMORY: SEAT ADJUSTER, MIRROR, POWER, DRIVER, PERSONALIZATION

HEATER SEAT FRT: DRVR and PASS

A20-Radio/HVAC Controls

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

K40-Seat Memory Control Module

Heated Seat Operation

The driver and passenger heated seats are controlled by separate heated seat switches.Both switches are located in the radio/HVAC controls. When a heated seat switch ispressed, a LIN-Bus message is sent from the radio/HVAC controls to the HVAC controlmodule. The HVAC control module then serves as a gateway to transmit the message tothe seat memory control module/seat heating control module via serial data line indicatingthe heatedseat command. In response to this message, the seat memory control module/seat heatingcontrol module applies or removes battery voltage through the element supply voltagecircuit of the seat heating elements. The seat memory control module/seat heatingcontrol module sends a serial data message back to the HVAC control module to gatewaythe information to the radio/HVAC controls to either illuminate or turn off the appropriatetemperatureindicator.

Temperature Regulation

The seat memory control module/seat heating control module monitors the seat temperaturethrough the temperature sensor signal circuit and the temperature sensor (thermistor)located in the seat cushion with the heater element. The temperature sensor is a variableresistor, it's resistance varies as the temperature of the seat changes. When thetemperature sensor resistance indicates to the seat module that the seat has reachedthe desiredtemperature, the module opens the ground path of the seat heating elements throughthe heated seat element control circuit. The module will then cycle the element controlcircuit open and closed in order to maintain the desired temperature.

Remote Start Seat Heating and Ventilation

Some vehicles allow the customer to configure their heated and/or ventilated seatsto come on after a remote start is commanded. The heated seats will only come on ifthe outside air temperature is below 50°F as measured by the outside air temperaturesensor. When seat heating is commanded, the heating level will be on the “High” setting.On some vehicles, the LED display for the temperature level may not illuminate duringremote startoperation. When the vehicle operator inserts the key in the ignition and turns itto the “On” position, the heated seats will automatically turn off. Be aware thatduring remote start heated seat operation, since there is no occupant in the seat,the customer may comment that they feel little or no difference in the temperatureof the seat. This is due to little heat transfer to the seat cover occurring sincethere is no weigh on the cushion.Once the seat is occupied and the seat cover is pressed against the heater element,heat will begin to transfer more rapidly to the seat cover.

Load Shed Management

The electrical power management function is designed to monitor the vehicle electricalload 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 duringa battery discharge condition. For more information on load management refer toElectrical Power Management Description and Operation.