Climate Controlled Seat Recovery Mode

NOTE: The presence of overtemperature faults (DTCs B2729, B2730, B272A and B272B) can be induced by incorrectly operating the climate controlled seat system after an initial heat setting has been attained. If a heat setting is repeatedly turned off and on in an attempt to increase the seat temperature or repeatedly toggled between heat and cool modes, an overtemperature condition can result and the DTCs may be set.

If the temperature at one of the TEDs rises above 110 C (229.8 F) in the heat mode or 65 C (148.9 F) in the cool mode for more than 4 seconds, the DCSM records an overtemperature DTC, removes voltage from the TEDs and goes into recovery mode (blower only) for 30 seconds to cool down the TEDs . The same occurs if a temperature difference of 60 C (108 F) or greater is seen between the backrest and cushion TEDs on either front seat. The DCSM continues to monitor the TEDs while in recovery mode. If the temperature of the TEDs does not drop to 105 C (220.8 F) in the heat mode or 60 C (139.9 F) in the cool mode after 30 seconds, the system continues to cool the TEDs in recovery mode for up to 5 minutes. If the TEDs cool down after 30 seconds, but before 5 minutes (checked at 4 second intervals), the system operates as normal. An overtemperature DTC is still recorded even if the system recovers and is operating normally. This is more likely to occur during extreme cabin temperatures with significant seat back sun load. If the system does not recover within 30 seconds in heat mode or within 5 minutes in cool mode, the DCSM disables that seat (fault mode) and remains off until the ignition is cycled. Also, if the DCSM detects temperature differential fault twice during the same ignition cycle, the DCSM disables the seat. When a fault causes a shutdown, the climate controlled seat indicators turn off and that seat is not operational until the next key cycle.