Outside temperature (and hvac)

I've had two annoying problems with my Leggy since day one, and the dealer said it is "normal". And, now I'm thinking they might be related. And, I want to see if you guys have the same thing or if mine is truly in need of a sensor or something.

First, the outside temperature display. Mine is INCREDIBLY slow to register. To give you an example, I just pulled it out of the garage and got lunch at a drive through. Total trip was about 15 minutes. Temperature stayed at 66 the whole time, yet it is nearly 80 degrees outside. I mean, c'mon, over 15 minutes and it hadn't registered the temperature change? Are yours that slow?

And, my HVAC issue, which is very repeatable on a sunny winter day, if it is cold out, but sunny, my auto HVAC will COOK me. It keeps the heat on, even if I turn it down to as far as 66 degrees (both sides). But, if I go down to 65, then BOOM, it turns on the A/C, recirculate, dash vents and ice cold. There is no inbetween, so I have to knock it out of auto and do it manually.

It occured to me today that maybe these two problems are related and I have a bad sensor and I need to press the dealer more. But, I wanted to know what your experiences are with the outside temperature and auto A/C (in my scenario).

The auto HVAC actually uses a few sensors to work. Obviously, interior temp sensors. One per side. It uses the exterior temperature sensor to determine whether it should recirc or not. It also uses that little black dome on the dash to indicate sunlight and determine the settings.

If any one of those fails, who in the world knows what happens to the HVAC.

As was mentioned before, the auto HVAC system uses sensors to determine proper temperature and fan setting. Unfortunately it does a terrible job. Anyone you talk to here will tell you that. If you were expecting an intelligent auto climate control as offered in certain German brands, you will be very dissappointed.

Just use the manual settings and save yourself the headache.

Yes, I know the auto hvac pretty much sucks, but this example seems extreme.

But, on the other subject then, what about the outside temperature thing? Does yours take over 15-20 minutes to start to read the correct temperature?

The external temp sensor plays a role in all modern vehicles for a variety of functions - including the HVAC.

Go back to the dealer and go tell them to fix the external temp sensor. It may be just the sensor that's bad, so replacing it - or replace it yourself.

In any case - when the system has an error from some sensors - like the external temperature there is a fallback to last good value, which means that it is what you are experiencing. If a new sensor doesn't do the trick it's the ECU that the sensor is connected that is bad in some way.

Right now I'm rather deep into that world for the next generation of the Volvo FH series so I know that it's not something simple anymore like a temp sensor, two wires and a display. It's a crapload of CAN bus messages, error handling and fallback procedures involved. (Or how to make something very simple very complicated)