Pilot Assist/ Adaptive Cruise Control fault

[Superbenj]

I have recently began to an experience a fault in my 2018 XC60 whereby the Adaptive Cruise Control will 'lose' the car in front in a queue at close quarters.

This normally happens (but is not exclusive to) after I accelerate a bit myself to get moving or speed up a little over what the ACC is pulling itself.

On the dash (when in Pilot assist), the pilot assist steering wheel indicator wheel will remain green but both the car ahead and the distance lines disappear and the cars speed is no longer set by the car in front.

This is obviously pretty dangerous and these things need to be completely faultless in order to let you put your trust in them.

Luckily the car is due for its firs service soon anyway but I wanted to see if anyone else had experienced similar on here, or if any of the experts had an idea about what the problem could be.

Cheers
Ben

[antman99]

I may be wrong but on my 2016 xc60 with ACC i think this happens when I accelerate but when I stop it then reappears, has been a while so not 100% sure.

[Superbenj]

Originally Posted by antman99

I may be wrong but on my 2016 xc60 with ACC i think this happens when I accelerate but when I stop it then reappears, has been a while so not 100% sure.

Yup, I believe it does do that as standard, the problem I have is that upon letting off the accelerator its not not re-picking up the car in front!

[nu11eaf]

I am taking it that you are not touching the brakes at all as the green steering wheel light is still on, I am thinking it may be waiting for your set distance to be reached after you have accelerated. I dont know how hard you accelerated but all mine ever needs is a slight blip on the throttle to set it going again, accelerating harder may give what you are experiencing.

[Superbenj]

Originally Posted by nu11eaf

I am taking it that you are not touching the brakes at all as the green steering wheel light is still on, I am thinking it may be waiting for your set distance to be reached after you have accelerated. I dont know how hard you accelerated but all mine ever needs is a slight blip on the throttle to set it going again, accelerating harder may give what you are experiencing.

It seems to be both if I have broken myself and reengaged the pilot, or if the ACC has managed the speed and queuing all on its own and I've done a little tap on the throttle, or indeed a tap on the up arrow and the car starts to move but the car headed is not picked up again.

It is new behaviour by the car, not me. Im using it as I have been for 11 months

I should add that it is not occurring on every trip, maybe just 1-4,5. On other journeys, like my last it behaved as per normal.

Does the ACC work solely on radar or is it camera based too? Is there something I could simply clean?

[Superbenj]

I believe I have discovered and fixed the ‘fault’.

In a super high tech age the problem was very much old skool!

I believe the floor Matt has simply shifted forward and was putting light pressure on the throttle

Thus the ACC was was overidden by the throttle input which directed the car to move forward even when it didn’t want to.

Fixed and confidence fully restored in what had otherwise has been a faultless system.

They should really pin down the floor mats though (package that came with the car), so will get them to do that when it goes in for service, if I can’t easilly do it myself

[Kentish]

the genuine mats cannot move forward as they are fixed by the two large buttons at the rear

[S90]

Originally Posted by Superbenj

I believe I have discovered and fixed the ‘fault’.

In a super high tech age the problem was very much old skool!

I believe the floor Matt has simply shifted forward and was putting light pressure on the throttle

Thus the ACC was was overidden by the throttle input which directed the car to move forward even when it didn’t want to.

Fixed and confidence fully restored in what had otherwise has been a faultless system.

They should really pin down the floor mats though (package that came with the car), so will get them to do that when it goes in for service, if I can’t easilly do it myself

There are clips on the floor to hold the floor mats. You can do it yourself. As for systems being faultless, well, I think you need to read the manual. All these things are on cars to make life easier, not to drive for you. You should always cover the brake pedal no matter what, you should never put your trust in it!

[Superbenj]

Originally Posted by Kentish

the genuine mats cannot move forward as they are fixed by the two large buttons at the rear

...if they’d bother to set them in the first place.

I’m going to do it myself tonight.

The system has been faultless for me thus far, in that it has (until this experience) behaved exactly as I expect it too, I am fully aware it is an ‘assist’ and considering I managed this experience, I think I’m probably covering the manual aspect of it safely myself. I’d consider a ‘fault’ to be an actual breakdown of the system, not the fact it’s not quite picked up a line on the side of the road