Climate Controlled Seat System

NOTE: Avoid applying voltage directly to a Thermo-Electric Device (TED) for testing its operation. Doing so may cause damage to the TED.

NOTE: When installing a new Dual Climate Controlled Seat Module (DCSM), it is necessary to carry out Programmable Module Installation (PMI). Refer to Module Configuration .

Both the driver and front passenger climate controlled seats are independently controlled by the DCSM. The climate controlled seat system only operates with the engine running above 350 rpm, however, if using a scan tool to command the DCSM, diagnostic testing can be carried out with the ignition on and engine off. The DCSM does not time out. The DCSM receives voltage from the Battery Junction Box (BJB) on 2 redundant circuits. If one pin does not receive voltage, both seats will remain operational because the voltage supply circuits are internally connected in the DCSM.

If a fault occurs setting a DTC, only the affected seat will be disabled by the module. If the system shuts down due to a DTC fault, cycling the ignition OFF and then ON again will reset the DCSM to function until the DTC resets.

Each driver and front passenger seat cushion and backrest is equipped with a 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 is minimal. For example, it is difficult to distinguish between low cool and medium 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 APIM sends the climate controlled seat commands to the FCIM using the I-CAN. The FCIM sends the request message to the IPC using the I-CAN. The IPC sends the request message to the BCM over the HS-CAN. Finally the BCM sends the communicates climate controlled seat commands to the DCSM using the MS-CAN. The MS-CAN is connected to the 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 information concerning CAN.

The climate controlled seats can be commanded using the diagnostic tool to verify both module communication on the MS-CAN bus and operation of the DCSM. This method may be useful for isolating a control switch concern. It should also be noted that because MS-CAN bus communication is more robust and reliable than other methods, it may be possible to have limited module communication with one of the MS-CAN bus circuits disconnected or shorted to ground. Refer to Module Communications Network for information concerning MS-CAN bus communication.