April 8, 2014 "On some 2014 Corvettes built prior to November 15, 2013 the HVAC temperature may fluctuate more than expected when the set temperature is changed by only a few degrees or less. A minor change in the set temperature may cause the HVAC system to blow warmer or cooler than desired. Do not replace parts for this condition. A revised HVAC control module calibration has been released to provide an improvement to this condition.
- Determine the build date of the vehicle in order to confirm which module(s) require an update.
- If the build date is November 5, 2013 or later, update the HVAC control module.
- If the build date is prior to November 5, 2013, determine if the latest version of #PI1101 (labor operation code 2880178) has been performed.
- If the latest version of #PI1101 has been performed, update only the HVAC control module.
- If the latest version of #PI1101 has not been performed, perform the procedure as instructed. Submit a warranty transaction for #PI1101 only.
• The revised HVAC control module calibration will improve the condition noticeably, but if there are still concerns after the calibration has been updated, there are settings that can be made to further improve the operation. In the Vehicle Settings menu, set the Auto Fan Max Speed to Low or Medium instead of High. Go to Vehicle > Climate and Air Quality > Auto Fan Max Speed. (Fig. 12) By selecting a reduced blower speed, the system will have smoother temperature changes as it attempts to adjust the temperature in the car.
• It is vital to the operation of the system that all programming events be completed as instructed in the appropriate module Programming and Setup documents. System operation will not improve if procedures are not completed as instructed in the Service Information."