A4Q Climate Control Sun Sensor comment/question

[John Legelis <john.legelis@fmr.com>]

With ski season in full swing, the A4Q has been runing quite a number of trips from Boston to New Hampshire and Vermont.  As such, I've had some time to observe the response of the A4's climate control system in all sorts of cold weather conditions, from dark, overcast, and wintery, to bright, sunny and frigid.  In general the climate control seems to work quite well when left on 'auto', but I've noticed one scenario where it's not quite up to par.  On semi overcast days, with the sun peeking in and out of the clouds, it seems the sun sensor *over* compensates when the sun is shining by instructing the heater to not put out as many btu's, as compared with when the sun ducks behind a cloud. When the sun is out, I almost always need to elevate the cabin temp a few degrees - in fact, I can fool the sun sensor on bright days by covering it with a dark glove (it then thinks there's no sun to warm the cabin, and boosts the heater output).  My passenger-seat thermostat (AKA wife) confirms a warmer cabin on sunny days when the sun sensor covered up.   

Does anyone know if the sun-sensor compensation is adjustable??  I'd like to reduce the sun-sensor releated temperature decrease in bright conditions...

John Legelis
Boston
'97 A4Q