Phantom braking (TACC/AP) [Not AEB]

[Adopado]

With regards to being rear-ended as a result - this is always the fault of the driver behind. Everyone should leave a big enough gap to be able to stop in time, and it's something I always make a point of doing.

Technically yes, but I can’t imagine feeling any great sense of satisfaction knowing that it was the guy behind me who was at fault when he’s just crumpled the rear of my car!

 

[meavydev]

You can mitigate the problem by just covering the accelerator pedal when going past lorries or other events you are worried about.
It's the way I learnt to drive the i3 on cruise control, as it would phantom brake when going past lorries / bridges / shadows and pretty much anything just for the hell of it

 

[Rustybkts]

I find driving on TACC and preparing for the worst by covering the accelerator pedal is more stressful than driving old style.
I can't be rocket science (Musk is good at that) to stop trucks jumping in to an empty lane on the visualisation and causing PB.

Visualisation displays clear road lines on motorways etc so why can't it realise that trucks are not staying in the lanes it can see?

 

[Maka344]

Moderation note - thread merged with existing

Has anyone experienced phantom braking when using the basic auto pilot mode? It has been mentioned a lot within YouTube reviews.

Sounds pretty scary when it happens at motorway speeds. We have an 8 month old baby and wouldn’t fancy being in that position on the motorway. I’ve experienced it once in my Goof R but at 30mph.

I’m not keen to experience it at 70mph with my daughter in the car. I am in two minds about proceeding with my order. Not being able to use cruise control would be a big issue as we do lots of long journeys.

I read somewhere that they are changing the way the system works? Possibly cameras vs radar?

 

[Stranger Dings]

Yep. It’s pretty bad.

It’s not too scary once you are used to it and ready to hit the accelerator when you pass a lorry or change lanes. It does scare passengers though, which isn’t ideal.

 

[Maka344]

Yep. It’s pretty bad.

It’s not too scary once you are used to it and ready to hit the accelerator when you pass a lorry or change lanes. It does scare passengers though, which isn’t ideal.

Damn that’s not what I wanted to hear. My daughter is 8 months old and I don’t think I can take the risk of it potentially causing us to be rear ended in the motorway. I’ve experienced it a couple of times in my Golf R but only at 30mph which is pretty manageable without being rear ended.

I’m now thinking of cancelling my order.

 

[M3noob]

Yep. It’s pretty bad.

It’s not too scary once you are used to it and ready to hit the accelerator when you pass a lorry or change lanes. It does scare passengers though, which isn’t ideal.

OTOH I drive to Spain and back, 2000 miles, mostly on full Autopilot with FSD and maybe two full fledged incidents and some slight flinches. Not scary just keeps me awake.

 

[Yachtsman]

If you put the slightest pressure on the go faster pedal (while in cruise) when passing hgv’s, just enough to let the car know you are aware & it doesn’t brake.

 

[Yachtsman]

This a slightly different scenario where the same actions work.
You are using TACC & currently travelling slower than the set max speed due to traffic immediately in front.
You change lanes to your inside, I.e. to the hard shoulder which is now clear in front of you and you notice the car won’t undertake until you apply slight pressure to the accelerator effectively saying it’s ok undertake, and she does. I like it it’s a nice safety touch.

 

[Fursty Ferret]

You change lanes to your inside, I.e. to the hard shoulder which is now clear in front of you and you notice the car won’t undertake until you apply slight pressure to the accelerator effectively saying it’s ok undertake, and she does.

Drives me nuts. Way too law abiding and annoying at junctions where lane 1 becomes a slip road that's often moving faster than traffic still on the motorway.

 

[Maka344]

I’m now extremely concerned about this, I have ordered a M3LR - I don’t mind the slight reduction in speed here and there, the warnings or slight jolts but full on emergency stops on the motorway is too much of a risk with my currently 8 month child I the back. Quite frankly, it’s dangerous.

 

[candida]

Damn that’s not what I wanted to hear. My daughter is 8 months old and I don’t think I can take the risk of it potentially causing us to be rear ended in the motorway. I’ve experienced it a couple of times in my Golf R but only at 30mph which is pretty manageable without being rear ended.

I’m now thinking of cancelling my order.

I too had a Golf R before my M3P; I wouldn't want to persuade or dissuade you but my experience is that the Golf's radar cruise was pretty much faultless compared with Tesla's implementation. And you can forget using it at 30mph in city streets, it sees so much it panics the whole time

 

[Somex]

I too had a Golf R before my M3P; I wouldn't want to persuade or dissuade you but my experience is that the Golf's radar cruise was pretty much faultless compared with Tesla's implementation. And you can forget using it at 30mph in city streets, it sees so much it panics the whole time

My e-golf was also had faultless adaptive cruise control PLUS it had a resume button, it’s a pain to have to “reset” the Tesla one if you have to touch the brakes any time.
AND the auto wipers worked AND the auto headlight dip also worked

 

[Yachtsman]

Drives me nuts. Way too law abiding and annoying at junctions where lane 1 becomes a slip road that's often moving faster than traffic still on the motorway.

This still applies when moving to an inner lane (not to undertake), I like the fact that the won’t undertake without permission.

 

[candida]

This still applies when moving to an inner lane (not to undertake), I like the fact that the won’t undertake without permission.

I don't think its a blanket rule that you cant move faster than the lane to your right:

But I quite like it waiting for me to give it permission too.

 

[MrBadger]

Its also apparently speed related - below a certain speed, can't be bothered to look in the manual but its either 40 or 50mph, the car will undertake regardless. I used the term apparently speed related because this speed limit appears not to be a hard and fast rule as I have had AP want to merrily undertake at higher speeds than 50 mph, some of those times on long motorway exit lanes, eg between M25 clockwise J11 & J12 even if not at that point marked as an exiting lane, but in other locations, no obvious reason. It also can only detect an undertake on an adjacent lane.

 

[AndrewGR]

Once you have accelerated in TACC in order to undertake, the car will continue to undertake on TACC for the rest of the journey. This feature is documented in the manual.

 

[AndrewGR]

I wouldn’t describe most of my experiences of phantom braking in TACC as “full on emergency braking” but when they happen at 70 mph, I’d say there is more braking than if you simply took your foot off the pedal at the same speed. Disconcerting but not usually likely to get you rear ended.I’ve experienced full on AEB a couple of times from less than 30 mph when in normal driving and the car has decided I am going to hit an obstruction ahead and I need to slow down or steer away faster. Now that is disconcerting! I’ve got used to being prepared for phantom braking when passing HGVs in TACC. It’s the braking for bridges that catches me out. There is one on the M4 just west of Swindon which is a regular spot - perhaps 1 in 5 times I go under it.

 

[MrBadger]

Once you have accelerated in TACC in order to undertake, the car will continue to undertake on TACC for the rest of the journey. This feature is documented in the manual.

That's definitely not the situation with the M25 J11/12 as its immediately after joining the motorway and if the 'in order to undertake' is the override, then that is also not the situation as I never undertake other vehicles unless in queuing traffic, in which case the 50mph cutoff will handle that situation. I can't recall reading that so will throw it in to the occasion next time as a possible cause but I really do not think it is the override. tbh, 'for the rest of the journey' is a pretty far reaching override and without reading more, that would sound like a design defect to me as the only way to prevent the undertake is to hit the brakes to disengage TACC or franticly wind down the speed on the scroll wheel which is hit and miss whether that will be enough to scrub the speed in time.

Update. A lane change (or cancel/restart TACC) will cancel the undertake override so thankfully its not for rest of the journey. And speed limit is 50mph. Weird that they omitted 50mph in later version, and stuck with 80kmh.

 

[AndrewGR]

OK - I remembered wrong! This is from the manual:
Passing Vehicles in Non-Passing Lanes
If traveling 80 km/h or faster, Traffic-Aware Cruise Control requires that you be in a passing lane in order to pass a vehicle. If you are in a non-passing lane (to the right of a vehicle in right-hand traffic, or to the left of a vehicle in left-hand traffic), Traffic-Aware Cruise Control prevents you from passing other vehicles. Instead, Model 3 slows down to match the vehicle’s speed as if it were in the same lane as your vehicle. If you press the accelerator pedal to pass the vehicle, Traffic-Aware Cruise Control allows you to pass vehicles in the non- passing lane until you either change lanes or cancel and resume cruising (it then prevents you from passing vehicles in a non-passing lane again).