Climate Controlled Seat System

WARNING: This page is about a different car, the 2010 Mercury Milan, 2010 Lincoln MKZ, and 2010 Ford Fusion. 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 .

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 .

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, 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 receives voltage from the Battery Junction Box (BJB) on DCSM C3265a pins E and F. 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 is detected, only the affected seat will be disabled. If the system shuts down, cycling the ignition OFF and then ON again will reset the DCSM to function until the DTC resets.

The 4 buttons (identified with seat icons), located on the FCIM , activate each seat system setting and illuminate indicators on each button to indicate the operating mode, 3 indicators for HIGH, 2 indicators for MED or 1 indicator for LOW. The push-buttons with the blue seat icon operate the seat cooling mode and the push-buttons with the red seat icon operate the seat heating mode.

The climate controlled seat button commands are communicated from the FCIM over the MS-CAN to the HVAC module and then to the DCSM . Upon receiving a command, the DCSM then communicates indicator illumination commands back to the HVAC module which then commands the FCIM to turn the indicators on or off. The climate controlled seat system can only operate if all 3 modules are communicating correctly on the CAN .

Each 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 ). Applying voltage polarity to the TED in one direction, causes it 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 manifold where it is distributed along the surface of the cushion and backrest of the seat. Once the system is activated, the DCSM controls the heating/cooling modes and the blower speed dependant on the 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 climate controlled seats can be commanded using the scan 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 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 information concerning CAN bus communication.