System Operation

Seating - Heated

System Operation

System Diagram





Network Message Chart

HVAC (Heating, Ventilation, and Air Conditioning) Module Network Input Messages





APIM (Accessory Protocol Interface Module) Network Input Messages






The driver and passenger heated seat buttons are selected from the touchscreen interface. When the heated seat button is pressed on the touchscreen interface, the APIM (Accessory Protocol Interface Module) sends the request message to the FCIM (Front Controls Interface Module) over the I-CAN (Infotainment Controller Area Network). When a heated seat request message has been received from the APIM (Accessory Protocol Interface Module), the FCIM (Front Controls Interface Module) sends the request message to the IPC (Instrument Panel Cluster) over the I-CAN (Infotainment Controller Area Network). The IPC (Instrument Panel Cluster) sends the message to the BCM (Body Control Module) over the HS-CAN (High Speed Controller Area Network). The message is then sent to the HVAC (Heating, Ventilation, and Air Conditioning) module over the MS-CAN (Medium Speed Controller Area Network). Upon receiving the request, the HVAC (Heating, Ventilation, and Air Conditioning) module supplies voltage to the appropriate driver and/or passenger seat cushion and backrest heater mats.

Heated Seats

The driver and passenger heated seat control buttons and indicators are located on the touchscreen interface (FDIM (Front Display Interface Module)). The FDIM (Front Display Interface Module) is mounted directly to the APIM (Accessory Protocol Interface Module). The heated seat system functions independently of the vehicle's climate control system. Each time the heated seat button is pressed, the APIM (Accessory Protocol Interface Module) sends the request to the FCIM (Front Controls Interface Module) using the I-CAN (Infotainment Controller Area Network). The FCIM (Front Controls Interface Module) sends the message to the IPC (Instrument Panel Cluster) using the I-CAN (Infotainment Controller Area Network). The IPC (Instrument Panel Cluster) sends the request message to the BCM (Body Control Module) over the HS-CAN (High Speed Controller Area Network). Finally, the BCM (Body Control Module) sends the request to the HVAC (Heating, Ventilation, and Air Conditioning) module which decreases one setting (the sequence is high, low, off, high, etc.).

When activated, the HVAC (Heating, Ventilation, and Air Conditioning) module supplies voltage to the selected seat's heater circuit. Each seat's cushion heater mat and backrest heater mat is connected in a series circuit to the HVAC (Heating, Ventilation, and Air Conditioning) module and powered by the output circuit for that seat. The HVAC (Heating, Ventilation, and Air Conditioning) module monitors inputs from a temperature sensor located in each seat's cushion heater mat, and maintains seat temperature by cycling the heater circuits on/off. The heated seat remains ON until the heated seat switch button is pressed to cycle the HVAC (Heating, Ventilation, and Air Conditioning) module OFF or the ignition is set to OFF.

If a fault is detected by the HVAC (Heating, Ventilation, and Air Conditioning) module, the module stops supplying voltage to that individual left or right seat that the fault was detected on until the ignition is turned OFF and then ON.