[shaggyusm]

Originally Posted by nissanmastatek

OK first of all lets have a short lesson on how this system works for those of us who are squabbling over system operation and whether to call it fast cycling or short cycling. The ECM uses a combination of readings from the a/c pressure sensor, in cabin sensor, and thermal control amplifier. All these sensors (like most items on cars) have 5 different names, so shut up and play nice, you know what i am talking about. The ECM uses these readings and controls compressor clutch engagement accordingly. Therefore, an ecm re-flash would remedy this situation. Also, normal cycling is used for a variety of reasons. Fuel economy yes, but when fast cycling this will be compromised as loading and unloading the engine uses more fuel. Mostly it is used to control cabin temperature and prevent evaporator freeze up, as well as prevent wear etc. finally, this doesnt seem to be a problem off idle, and yes it should happen more often with the fan on 1 setting as the lower the fan speed, the cooler the evaportor will be.

That definitely makes sense. As with having the fan on "1", I also think that while driving, the compressor doesn't kick on as much because of the air moving over all the A/C parts under the hood that would be more sensitive to freezing up at a rest. There isn't as much under-hood-air-circulation while sitting, at say, a drive-thru. I know the compressor doesn't cycle like that while driving because you'd be able to feel it. I can tell when the compressor clutch engages at lower speeds and it's definitely not as often as it does sitting at a drive-thru or in a driveway.
Thanks!