System Operation
Seating - Climate Controlled
System Operation
System Diagram
Network Message Chart
DCSM (Dual Climate Controlled Seat Module) Network Input Messages
APIM (Accessory Protocol Interface Module) Module Network Input Messages
When the climate control seat buttons are activated on the touchscreen interface, the APIM (Accessory Protocol Interface Module) sends the climate controlled seat commands to the FCIM (Front Controls Interface Module) using the I-CAN (Infotainment Controller Area Network). The FCIM (Front Controls Interface Module) sends the request 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 climate controlled seat commands to the DCSM (Dual Climate Controlled Seat Module) using the MS-CAN (Medium Speed Controller Area Network).
Climate Controlled Seat System
The seat cushion is equipped with a TED (Thermo-Electric Device) assembly that includes a seat blower (fan motor, serviced as an assembly with the TED (Thermo-Electric Device)). Similarly, the seat backrest is also equipped with its own TED (Thermo-Electric Device) assembly with blower. Cabin air is drawn through the blower and distributed to each TED (Thermo-Electric Device) located in the seat cushion and backrest. The TEDs (Thermo-Electric Devices) heat or cool the air, which is then directed into the foam pad and manifold where it is distributed along the surface of the cushion and backrest of the seat. Once the system is activated, the DCSM (Dual Climate Controlled Seat Module) uses a set of flexible algorithms to control the heating/cooling modes and the blower speed dependant on the commanded climate controlled seat settings.
The DCSM (Dual Climate Controlled Seat Module) monitors seat cushion temperature while it supplies voltage and ground to both blower motors. The DCSM (Dual Climate Controlled Seat Module) also supplies a variable voltage signal to control the blower speed. Cabin air enters the blower through a filter attached to the TED (Thermo-Electric Device) housing. Heated or cooled air exits the TED (Thermo-Electric Device) and flows through a manifold attached to the foam pad.
Climate Controlled Seat Heating Characteristics
- In heat mode, the TED (Thermo-Electric Device) can add up to 40-60 C (72-108 F) to the ambient inlet air temperature as it passes over the TED (Thermo-Electric Device).
- The system control settings are indicated next to each climate controlled seat heat switch button on the touchscreen. The first setting is HIGH (3 indicators), the second setting is MED (2 indicators) and the third is LOW (1 indicator) then OFF (no indicators).
- When heating, the DCSM (Dual Climate Controlled Seat Module) varies the speed of the blowers and the TED (Thermo-Electric Device) duty cycle in order to reach and maintain the desired temperature determined by the switch setting.
Climate Controlled Seat Cooling Characteristics
- In cool mode, the TED (Thermo-Electric Device) can remove up to 8 C (14 F) from the ambient air temperature entering the system.
- The system control settings are based on the 3 indicators next to each climate controlled seat cool switch button on the touchscreen. The first setting is HIGH (3 indicators), the second setting is MED (2 indicators) and the third is LOW (1 indicator) then OFF (no indicators).
- When cooling, the DCSM (Dual Climate Controlled Seat Module) maintains constant speed of the blowers and constant TED (Thermo-Electric Device) supply voltage (duty cycle is determined by the switch setting) in COOL mode.
Climate Controlled Seat Recovery Mode
NOTE: The presence of overtemperature faults (DTCs (Diagnostic Trouble Codes) B2729, B2730, B272A and B272B) can be induced by incorrectly operating the climate controlled seat system after an initial heat setting has been attained. If a heat setting is repeatedly turned off and on in an attempt to increase the seat temperature or repeatedly toggled between heat and cool modes, an overtemperature condition can result and the DTCs (Diagnostic Trouble Codes) may be set.
If the temperature at one of the TEDs (Thermo-Electric Devices) rises above 110 C (229.8 F) in the heat mode or 65 C (148.9 F) in the cool mode for more than 4 seconds, the DCSM (Dual Climate Controlled Seat Module) records an overtemperature DTC (Diagnostic Trouble Code), removes voltage from the TEDs (Thermo-Electric Devices) and goes into recovery mode (blower only) for 30 seconds to cool down the TEDs (Thermo-Electric Devices). The same occurs if a temperature difference of 60 C (108 F) or greater is seen between the backrest and cushion TEDs (Thermo-Electric Devices) on either front seat. The DCSM (Dual Climate Controlled Seat Module) continues to monitor the TEDs (Thermo-Electric Devices) while in recovery mode. If the temperature of the TEDs (Thermo-Electric Devices) does not drop to 105 C (220.8 F) in the heat mode or 60 C (139.9 F) in the cool mode after 30 seconds, the system continues to cool the TEDs (Thermo-Electric Devices) in recovery mode for up to 5 minutes. If the TEDs (Thermo-Electric Devices) cool down after 30 seconds, but before 5 minutes (checked at 4 second intervals), the system operates as normal. An overtemperature DTC (Diagnostic Trouble Code) is still recorded even if the system recovers and is operating normally. This is more likely to occur during extreme cabin temperatures with significant seat back sun load. If the system does not recover within 30 seconds in heat mode or within 5 minutes in cool mode, the DCSM (Dual Climate Controlled Seat Module) disables that seat (fault mode) and remains off until the ignition is cycled. Also, if the DCSM (Dual Climate Controlled Seat Module) detects temperature differential fault twice during the same ignition cycle, the DCSM (Dual Climate Controlled Seat Module) disables the seat. When a fault causes a shutdown, the climate controlled seat indicators turn off and that seat is not operational until the next key cycle.