Almost...almost

Haven't you seen all the videos of people sleeping in their Teslas while cruising down the expressway? Here's one I saw on the local news two days ago. There are other videos (not linked) of people doing other things besides watching the road while traveling in their Teslas, too.

 

I find LKAS is very good on interstates even when the markings are quite faint, but on the twisty roads that we have in VT not so much. The only thing that somewhat irritates me is the steering nag when no steering is actually needed because the interstate in the midwest is a totally straight line. I just jiggle the wheel a little so it knows I'm not asleep.

 

I realized today that a lot of the unexpected braking I'm getting isn't the FCW at all, but the ACC. I counted something like 5 inexplicable slowdowns today on the way to work, a couple when the car in front of me moved into another lane, once as I approached a bridge, and even once with no car in front of me (and no filled in 'target acquired' car on the dash).

It happens often enough to be a frustration, but I'm beginning to change my mind about whether it is acceptable. With that number of unexpected braking events in a given trip, it's entirely possible the ACC could lead to a lot more impacts than it would prevent. Of course, to the extent they are cause by people behind you not expecting you to brake, they might not show up in crash data as the "fault" of the Clarity.

Not that there are enough Clarities (Claritys?) to get meaningful crash statistics.

I have also noticed that sometimes applying the gas with the ACC on can result in the car to slowing down, which is super counter-intuitive. My guess is I'm not applying as much throttle as would be necessary to maintain speed, but because I'm depressing the gas pedal, the ACC is deferring to my foot.

This is really noticeable right when I turn on the ACC, e.g. after a braking event. It goes something like this:

1. Cruise set to 70, but someone cuts in and I brake down to 50.
2. Once I have enough space, I click "Resume"
3. The car takes way longer to accelerate than the folks behind me will permit, and there's nothing but daylight in front of me, so I press the gas pedal until I'm at ~60.
4. I let off the gas pedal to allow the ACC to take over; the Clarity slows down, with the throttle indicating dropping below 0 to "charging".
5. Something like a full second later (which seems like an eternity) the ACC realizes it's going 10 under the set speed of 70, with no vehicle in range, and kicks the throttle up.

Ideally, the acceleration would just seamlessly move from pedal control to ACC throttle, but I have to hang on the accelerator much longer than I would intuit in order for that to happen.

 

I just used the ACC the other day for the first time on my Clarity. You basically summed up all of my thoughts on it as well, unfortunately it has enough nuisances that it doesn't seem worth using unless you're really in the middle of nowhere and not much traffic is around...

 

ACC slowing when a car in front of you moves out of the lane is normal, at least for Clarity. It seems as if the system sort of "radar locks" on the car in front of you, and as that car drifts to the right ACC does not always feel confident that it is clear of your lane so as your distance to the other car closes it reacts and slows down. I have gotten to where I anticipate this and apply throttle when the initial slight slowdown begins prior to the heavier slowing. Never had it actually brake in those conditions though. Combined with the bridge incidents I wonder if your system has an alignment issue. But that's hard to say, maybe all of our cars would react the same way if they were in those identical situations. I just know I use ACC pretty much all the time, I feel it greatly enhances safety by helping me always keep proper distance from the car in front. I really can't think of an incident where I thought it could have caused an accident. Not saying yours hasn't I'm just reporting on my experience.

Yes definitely that is how my car works, I find it somewhat strange and unlike regular cruise control, but maybe it's common for ACC systems to work that way. I also don't like that it won't show my set speed while I am using the throttle, it goes blank until you release the throttle (and of course start slowing down) only then does it show what the previous setting was. I would actually like to be able to even adjust the set speed while I am accelerating, but I guess they consider that too much workload for the moment and they may be right. And maybe that's why it goes blank otherwise you would be trying to change the speed and it would seem like it's not working.

 

Have you tried using ACC in normal (i.e. eco off) or even better (for some) in sport?

Manual pedal operation gets you to speed about the same way in any mode if you press fast and far enough on the go pedal. (definitive testing by @Fast Eddie B some months back)

ACC is very different. In ACC, ECO is snow blower or lawn mower "Turtle" mode, sport "Rabbit" mode.

 

It will help if you put it in SPORT, or at least take it out of ECON. It will then accelerate faster back up to set speed (once it decides to do so).

If the ACC is giving you that many false readings, the camera behind the windshield or the radar behind the H emblem on the front below the hood may be misaligned.
Or it could be something more.
Here’s a total WAG, but you might try doing a hard reset by disconnecting the negative 12V battery terminal. Sometimes this will correct the odd electronic “hiccup”.

 

Regarding taking it out of "Eco" mode: I thought about that yesterday after my post, and drove the route home with ACC pretty much the entire way, and Eco off.

The car is definitely more responsive to the vehicle in front with Eco off, but I still had one exasperating slowdown on a (slight) hill where there was no vehicle in range, but there was a lot of traffic around that could have thrown it off. I actually yelled at the car ("Why the heck are you slowing down???") before I hit the gas pedal. This slowdown was near a pretty dangerous on-ramp on the highway and could have easily caused confusion to the folks behind me (and it definitely caused some angry passing).

One of these days I'll take down the dash cam and compile a bunch of videos of these instances- the downside being you won't get my dash in the video, just the road. But you will get to hear my reactions which could be fun?