It could be a warning that you have a code going off. To check your computer for codes have the key in the off position, press down on the temp. knob (auto) and the circulate button on the climate control and turn your car on, it should flash a few times then let go of the buttons and your codes will show up to let you know what is wrong. To find out what the codes are you can search the forum because someone listed them previously. Also, if a code 21 comes up, it is from your heat sensor which is no big deal, just means your car is probobly in the shade and cannot detect the light. Let me know what happens.. keep us posted :)