Owners of 2005 Saturn Relay minivans may come into your store with some rather strange air conditioning complaints.
Among the comments you might hear are that the system won't change modes, the A/C button won't respond when depressed, the push button LEDs are brighter than the rest of the control head when the headlights are on and/or the temp control function is inoperative.
According to GM, all these problems are the result of software gremlins in the HVAC control module. Reprogramming the module with updated software should eliminate the concerns. Check with a dealer for the specifics of the flash.