Climate Controlled Seat System: Notes
Both the driver and front passenger climate controlled seats are independently-controlled electronically by the DCSM mounted to the bottom of the passenger seat cushion. The climate controlled seat system only operates with the engine running. However, if using a scan tool to command the DCSM , diagnostic testing can be carried out with the ignition on engine off in 15 second durations.
If a fault occurs setting a DTC specific to either climate controlled seat, only the affected seat is disabled by the module. If the system shuts down due to a DTC fault, cycling the ignition to OFF and then ON again resets the DCSM to function until the DTC resets.
Each driver and front passenger seat cushion and backrest is equipped with a Thermo-Electric Device (TED) and blower motor assembly. Voltage is applied to the TED to heat/cool the seat. Applying voltage polarity to the TED in one direction causes the TED to heat. Applying voltage polarity in the opposite direction causes the TED to cool. Cabin air is drawn through the blower and distributed to each of the TED modules located in the seat cushion and backrest. The TEDs then heat or cool the incoming air depending on the control switch settings. The air 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 activated, the DCSM maintains the heating/cooling modes until deactivated.
The temperature differences between the individual heated and cooled settings are minimal. For example, it is difficult to distinguish between LOW cool and MED cool settings. Measuring seat temperature at different settings is possible by monitoring the DCSM PIDs using the scan tool.
When the climate control seat buttons are activated on the touchscreen interface, the Accessory Protocol Interface Module (APIM) sends the climate controlled seat commands to the FCIM using the I-CAN . The FCIM sends the request message to the IC using the I-CAN . The IC sends the request message to the Body Control Module (BCM) over the HS-CAN . Finally the BCM sends the communicates climate controlled seat commands to the DCSM using the Medium Speed Controller Area Network (MS-CAN). The MS-CAN is connected to the Data Link Connector (DLC) for diagnostic use. No direct connection exists between the DCSM and touchscreen interface for the climate controlled seat buttons. The climate controlled seats can be commanded on or off using the scan tool to verify both module communication on the MS-CAN and operation of the DCSM . This method may be useful for isolating a control switch concern. Refer to MODULE COMMUNICATIONS NETWORK for additional information concerning CAN .