A/c Codes 21 And 23 Anyone Know What They Mean?

[lexlugar]

I got these codes to come up on my test of the A/C compressor. My mechanic says that the compressor is staying on the whole time. any help would be appreciated. thanks, lexlugar

[lexsc3]

21 is a solar sensor, basically most cars will come up with that from what im told, you dont have to worry about that one...23 is low freon level, which means you have a leak of some sort.

[SKperformance]

didn't you already post this???

and if you have had mechanic look at it then how come it didnt' get fixed?