Had an issue with the AC on the weekend. Driving Hwy 401 at speed and approximately 3200 rpm for 3 hours and AC is blowing lukewarm air. Set fan at speed 4 and interior air recirculated. No change for whole trip. Next morning left house and turned AC on and it appeared to be normal. When there was no cold air it almost seemed like the compressor was not working but I can't confirm that. Car is now at dealer for 2 days and they are struggling to find the issue. I think they are going to try the evaporator temperature sensor tomorrow. Anyone have any other ideas?