Pinpoint Test AF : B272C: Notes

Refer to Climate Controlled Seats for schematic and connector information.

Normal Operation and Fault Conditions 

The DCSM is supplied voltage at all times, but the climate controlled seat system only operates with the engine running. The system can be operated with the ignition ON engine OFF by using a diagnostic scan tool to bypass the climate controlled seat buttons on the touchscreen interface. When commanding a heat or cool mode operation in this manner, the climate controlled seat system only operates in 15 second intervals. Both voltage supply circuits are spliced together internal to the DCSM, so if one circuit becomes open, both seats can still be operated. However, if a fault occurs setting a DTC specific to either climate controlled seat, only the affected seat is disabled by the DCSM.

Cabin air is drawn through and distributed to each of the blower motors located in the seat cushion and backrest. The blower motors then heat or cool the air. The air is then directed into the foam pad 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 commanded climate controlled seat settings.

A differential fault occurs when the cushion and backrest TEDs on an affected seat are reporting very different temperatures to the DCSM. This may result from an air flow restriction or a circuit fault of either TED. If a TED and manifold is clear of obstruction and is operational, check the other TED and circuitry on the seat. It is important to note that a TED with a higher temperature may be operating correctly and not the area of concern. The other TED may be indicating a much lower temperature, causing the DTC to set.

DTC Fault Trigger Conditions