Climate Controlled Seat System

WARNING: This page is about a different car, the 2010 Lincoln MKX and 2010 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.

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

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 electronically by the DCSM mounted under the front passenger seat. 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 and the engine OFF. The system receives voltage on 2 fused circuits from the Battery Junction Box (BJB). If one of the voltage circuits to the DCSM is lost, both seats will remain operational because the circuits are internally connected in the DCSM . If the system shuts down due to a DTC fault, cycling the ignition to off and then on again will reset the DCSM to function until the DTC resets.

Both climate controlled seats operate independently. If a fault occurs setting a DTC specific to either climate controlled seat, only the affected seat will be disabled by the module and the other will remain operational.

The 4 switches (identified with seat icons) on the HVAC module activate each seat system setting and illuminate LEDs above each switch to indicate the operating mode, 3 LEDs for HIGH, 2 LEDs for MEDIUM or 1 LED for LOW. The push-buttons with the blue seat icon operate the seat cooling mode and the pushbuttons with the red seat icon operate the seat heating mode.

Each driver and front passenger seat cushion and backrest is equipped with a Thermo-Electric Device (TED) assembly that includes a seat blower (fan motor, serviced as an assembly with the TED ). 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 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 the system is activated, the DCSM uses a set of flexible algorithms to control the heating/cooling modes and the blower speed dependant on the HVAC seat switch settings.

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.

The HVAC module communicates climate controlled seat commands to the DCSM using the MS-CAN communication bus. The MS-CAN bus is connected to the Data Link Connector (DLC) for diagnostic use. No direct connection exists between the DCSM and HVAC for the climate controlled seat switches. The climate controlled seats can be commanded using the scan tool to verify both module communication on the MSCAN bus and operation of the DCSM . This method may be useful for isolating a control switch concern. It should also be noted that because CAN bus communication is more robust and reliable than other methods, it may be possible to have limited module communication with one of the CAN bus circuits disconnected or shorted to ground. Refer to MODULE COMMUNICATIONS NETWORK for additional information concerning CAN bus communication.