DAP in Snow Conditions
 

I had an interesting experience this past week in upstate NY as I was driving the Northway to Lake Placid. We had wet snow and the roads were clear but very wet. I had the DAP engaged when the warning came on that it could not operate b/c it couldn't detect cars in front of me due to the conditions (even though conditions were clear), so the DAP disengaged. I found the cruise control will not work independently of the DAP so I had to keep my foot on the pedal for the rest of the trip. Although the DAP wasn't working, it still could detect lane changes and vibrated and corrected me if I crossed a lane. Same with blind spot detection. Obviously, they must work off of different sensors. When I arrived in Lake Placid, the entire front of the car was encased in slushy ice. I never had this happen with my other Q7's in similar conditions. I do not consider this an unusual weather condition and I'm concerned this is going to happen every time there's wet snow unless I pull over and manually clean the front. On the way home, I hit some snow squalls and the DAP turned off again b/c it couldn't detect objects but I was able to use it later on when things had cleared. There was no slush/ice on the front of the car this time. Anyone else with similar experiences?

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It happens every time to me also. I wish they put washer squirters on these sensors.

I have never been outside to check for myself but doesn't the headlight washer shoot up at the headlights and down to the sensors? I thought the sensors had their own washer the other day when I was looking at the right front bumper of the car but now that I think about it, it was possibly the tow hook cover. Didn't check to see if there was one on the left side, and it was lower, and more-center from the headlight washers.

In the US, headlight washers only with the Night Vision package. Included in Canada and elsewhere with the Prestige package equivalent I believe.

Yes, the ACC will stop working if there is slush on the little black radar domes at the outboard bottom of the grill. The radar can't see though the slush, so that makes sense. Annoying to have to stop the car and clean off the slush when the slush producing conditions stop. I wish the headlight washers sprayed the radar domes too.

I recently did a mod on my Q7 to add a washer spray for the rear camera that activates at the same time as the rear window washer. Got me thinking I could do the same for the radar domes tapped off the headlight washers (I have night vision, so I do have headlight washers).

Some concerns I have are: (1) not easy to get to the back of the headlight washers and radar domes; some hard to remove panels, (2) would the nozzles protruding from the plastic housing around the radar domes affect the radar functionality, (3) would the spray of water be sufficient to remove heavy slush, and (4) would the ACC cut off every time it's sprayed?

So, not sure if I'm going to attempt this or not. But perhaps this summer when it's warmer and cleaner for climbing under the car to remove panels.

Can't ACC be disengaged in these instances? I would think user can set car to simple cruise control without the forward monitoring function?

No, unfortunately. It's a poor design, but with ACC, it's all or nothing. If it can't do the adaptive part, then you have no cruise control at all.

Point could be made that if there is enough slush/ice to cover the sensors, manual driving might be preferred. BMW works the same way....

Its actually designed this way intentionally because perhaps you are smart enough, but the average joe is used to the car slowing down by itself now with ACC and will likely forget that ACC is not fully active and crash the vehicle. So yeah, they have to design it like this