I have an 02 Monte I am having a problem with the a/c and i got 2 dtc's the first code is: P1189c the second code is U1301 could either of these codes affect the performance of the a/c? The a/c is fully charged. Sometimes the compressor kicks in and sometimes it doesn't. Can contaminated freon cause this problem? When the compressor is working the a/c cools the car very well. Can anyone give me a hand? Any and all help is greatly appreciated. Also what are these 2 dtc's about? thank you in advance Brett

 

I noticed this on my 01 last year. It ended up being my thermostat sticking open and not letting the motor warm up to a normal operating temp. The computer recognized a problem with the temp of the motor and shut down the use of the A/C because the A/C can cause a motor to run hotter than normal. The computer does this as a precautionary function. Is it possible that your A/C works on warmer days when the motor temp gets a little warmer?