Normal Operation

The Dual Climate Controlled Seat Module (DCSM) monitors seat backrest temperature while it supplies voltage and ground to both blower motors. The DCSM also supplies a variable voltage signal to control the blower speed. Cabin air enters the blower through a filter attached to the Thermo-Electric Device (TED) housing. Conditioned air exits the TED and flows through a manifold attached to the foam pad.

• DTC B272B (Passenger Back Over-Temp Detected) - In the cooling mode, if the passenger seat backrest TED temperature exceeds 70°C (158°F) for more than 34 seconds, the TED is disconnected or the duct is blocked, the DCSM will shut down the passenger seat system and set this DTC.
• DTC B272B (Passenger Back Over-Temp Detected) - In the heating mode, if the passenger seat backrest TED temperature exceeds 85°C (185°F) for more than 34 seconds, the TED is disconnected or the duct is blocked, the DCSM will shut down the passenger seat system and set this DTC.

This pinpoint test is intended to diagnose the following: 

• Wiring, terminals or connectors
• Restricted backrest TED filter
• Crushed or restricted climate controlled seat manifold
• Backrest TED assembly