So I had the '22 D5 up in the Sierra/Tahoe area of California in December and had a weird system behavior.

The weather was a combination of snow and freezing rain with the temp right around freezing at 32... (0 for you other folks). As I approached a checkpoint the state's transportation division had setup to make sure you had chains or a 4x4 to go over a 7200' pass, the car suddenly started flashing red warning signs and said take control of the wheel as the cruise/assist system was about to fail. Sure enough if it did and a red warning triangle came up on the display and also, and this is the interesting part, the HUD displayed the same warning triangle and nothing else. The car also was telling me to pull over and stop the vehicle, but not really why I should do so. I promptly ignored that.

All the adaptive/cruise system controls on the wheel went dim as well and nothing was selectable for those functions (even manual speed control). What I assume was happening is the sensors at the front of the car had been frozen over and so the car just limited access to their use. Fine. What I find interesting though is that JLR chose to have the HUD be unusable during all this, simply showing the warning triangle, I get that the adaptive cruise and lane assist stuff isn't functioning, but it could still show navigation, right?

So the car remained in this state for about 20 minutes until I was well over the mountain pass, then suddenly it all just came back: HUD and the adaptive cruise system/lane guides etc. all started working again. Well, I could select things but it was obvious that the car distance sensors to a forward vehicle weren't working, all I could do was manually select a cruising speed (which was handy under those conditions). I never stopped the car. When I finally got to a place where I could stop the vehicle and look at the front, sure enough it was completely covered in ice. But if it was still covered, why was the system available now? The whole thing was a bit odd.

Wish I had stopped and taken pictures of all the warning displays, but considering the conditions, I was afraid if I stopped I'd get stuck.

Anyone else experienced this?

 

Where is the sonar located in this car? My wife has adaptive in her Tiguan and the sonar is located directly behind the VW logo and ice and snow build up and send it into a tail spin. That doesn't answer your problem with HUD but could be an issue with the ACC. Though I wouldn't be using cruise in that type of weather anyway.

 

on the bumper for sure, that's where the ice build-up was, there may be something behind the grill too, I'll have to look.

what I wanted to use was a manual setting of around 25 MPH when we were in a single line (as the LR manages braking too), but couldn't set even that as I said.

I may send something to JLR's customer support about this as they are actually pretty good about responding with decent info as they go to R&D for some questions.

 

My MY2019 does this is rain, if the front radar gets messed up it throws a wobbly and then takes an age to reset, very annoying that you cannot use manual cruise control either (same on mine) but it's one of those things....

 

We've found snow / ice / salt build up affect the adaptive cruise control and the foot activated trunk opening. The latter is quite a bit more serious when driving.

 

It is typically due to snow/slush or ice buildup. Same thing happened on my BMW's with the ACC as well as Audi's. Sensor is in the front and it will be covered in those weather conditions, its inevitable unfortunately.