High Temperature Fault State

WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

During the heating or cooling modes, if the TED temperatures listed below are exceeded for more than 4 seconds, the system will enter the High Temperature Fault State. At which time the CCSM will set the TED voltage duty cycle to 0%, set the blower speed control to maximum voltage to blow ambient air over the TEDs, attempting to reduce the TED temperature below the listed maximums. The system will operate in this mode for 30 seconds. If the over temperature fault still exists after 30 seconds, the system will transition to the FAULT state for the remainder of the ignition cycle. If the over temperature fault clears, the system will then transition to the appropriate heat or cool softstart mode. The following temperatures are based upon individual readings of either sensor:

Heat mode TED temperature exceeds 230°F (110°C).
Cool mode TED temperature exceeds 149°F (65°C).