Climate Controlled Seat System Recovery Mode

CLIMATE CONTROLLED SEAT SYSTEM RECOVERY MODE

NOTE: The presence of overtemperature faults (DTCs B2729, B2730, B272A and B272B) can be induced by incorrect operation of 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 DTC(s) will be set.

If the temperature at one of the TEDs rises above 110°C (230°F) in the HEAT mode or 65°C (149°F) in the COOL mode for more than 4 seconds, the CCSM will record an overtemperature DTC, remove power from the TEDs and go into recovery mode (blower only) for 30 seconds to cool down the TEDs. The same will occur if a temperature difference of 60°C (108°F) or greater is seen between the backrest and cushion TEDs on either front seat. The CCSM will continue to monitor the TEDs while in recovery mode. If the temperature of the TEDs does not drop to 105°C (221°F) in the HEAT mode or 60°C (140°F) in the COOL mode after 30 seconds, the system will continue to cool the TEDs in recovery mode for up to 5 minutes. If the TEDs cool down at anytime after 30 seconds, but before 5 minutes (checked at 4 second intervals), the system will operate as normal. An overtemperature DTC will still be recorded even if the system recovers and is operating normally. This scenario is more likely to occur during extreme cabin temperatures with significant seat back sunload. If the system does not recover within 30 seconds in HEAT mode or within 5 minutes in COOL mode, the CCSM will disable that seat (fault mode) and remain off until the ignition is cycled. Also, if the CCSM detects temperature differential fault twice during the same ignition cycle, it will shut down. When a fault causes a shut-down the climate controlled seat indicators will turn off and that seat will not be operational until the next key cycle.