Has your autopilot been spooked?

[Sixer]

This week I’ve spent a lot of time on motorways up and down the country with autopilot engaged.

On multiple occasions it seems my car gets completely spooked I.e it just slams on the brakes. This is typically after moving lanes - from the outside into the middle lane for example. This is the last thing I want the car to do!

The scenario is typically where I’m in the middle lane and I catch up to another car. I indicate and pull out into the outside lane. The car hesitates then goes up to 70. I pass the car in the middle lane and pull in. Just after I pull in it slams on the brakes for no apparent reason. It’s as if it gets totally spooked by something.

 

[Roy W.]

This week I’ve spent a lot of time on motorways up and down the country with autopilot engaged.

On multiple occasions it seems my car gets completely spooked I.e it just slams on the brakes. This is typically after moving lanes - from the outside into the middle lane for example. This is the last thing I want the car to do!

The scenario is typically where I’m in the middle lane and I catch up to another car. I indicate and pull out into the outside lane. The car hesitates then goes up to 70. I pass the car in the middle lane and pull in. Just after I pull in it slams on the brakes for no apparent reason. It’s as if it gets totally spooked by something.

I’ve never had what you’ve described. I use basic AP on all dual carriageways and motorways.
The few times I’ve had phantom braking (but never “slamming” on the brakes) are when there is an overhead bridge, and sometimes when a slip road peels off to the left.

 

[tess19]

I use AP a lot and never had slamming on the brakes either. The brake lights does come on everytime i lift off the accelerator. I bet this annoys the hell out of the cars behind.

 

[pgkevet]

I've had two nasty phantom brake episodes (as opposed to just slowing down a bit faster). No bridges or gantries either time. Once I was passing an artic. Scarely when it happens if there's a guy close behind.

 

[Puddles]

For quite a while I'd hoped that phantom braking was a thing of the past, but it seems to have resumed over the last update or two. I had a very strong one on the freeway today and the only thing around was an overcrossing, so I think that's back

 

[Sixer]

I too had it today when passing a big lorry. It’s not a full on emergency stop but it’s a strong application of the brakes not regen.

 

[LukeT]

I think folk's definition of phantom braking varies between a full-on hard brake application and an unnecessary and still quite quick and surprising deceleration by say 10mph, maybe just regen or maybe with a bit of friction brakes. They're different, obviously, but both are a clear failing of autopilot and need sorting. I get enough of the latter that I'm quite wary of autopilot use with any passengers in the car as a result. It's why I hover my foot over the accelerator. Equally, it accounts for much of the reason my other half won't use AP.

 

[Rooster6655]

This week I’ve spent a lot of time on motorways up and down the country with autopilot engaged.

On multiple occasions it seems my car gets completely spooked I.e it just slams on the brakes. This is typically after moving lanes - from the outside into the middle lane for example. This is the last thing I want the car to do!

The scenario is typically where I’m in the middle lane and I catch up to another car. I indicate and pull out into the outside lane. The car hesitates then goes up to 70. I pass the car in the middle lane and pull in. Just after I pull in it slams on the brakes for no apparent reason. It’s as if it gets totally spooked by something.

Well I’ve had this happen many times but it’s not the brakes usually it tries to take over the steering saying that I am departing a lane when I’m going into the middle lane. If I indicate then sometimes it doesn’t go off. I’ve turned off the emergency lane departure feature and it still happened

 

[MrBadger]

I think its something about driving style that triggers this, possibly leaving a bigger gap when manoeuvring helps. I had it happen to me once and I'm pretty sure it was adjacent lane speed. I've been in the car and its happened to swmbo twice on same motorway, and she also mentioned another incident. I've done significantly more miles on TACC/AP/NoA and would have expected me to have had the lions shares of unexpected braking/lifting off.

 

[Battpower]

I guess that I see one significant phantom braking event every 25 to 50 miles. The four broad areas I have linked them to are:

Mis-reading of traffic in close proximity to main highway. Parked cars, cars in driveways.

Misreading &/or inappropriate response to road layout and other traffic using the highway. Including rules about passing slow moving traffic and undertaking.

Misinterpretation of camera image due to lighting / shade / large undreadable objects / sudden extreme change in camera image.

Responding to incorrect speed data from GPS data.

Gradual slowing when approaching a potential hazard is to too bad, even if it turns out to not be a real hazard, but when the car suddenly brakes hard (slowing rapidly by 15mph or more) can be pretty dangerous.

 

[Pagemakers]

I too have experienced this emergency braking once or twice. Not just the normal phantom brake slow downs. Very disconcerting.

 

[Sixer]

I may try turning down my cruise control distance from 4 to say 3 to see if that makes any difference

 

[Pagemakers]

Mine’s always been set to 3 and it’s terrible since NOA update a few months ago.

 

[Bernard_S]

Having read most of the reports of Autopilot phantom braking I'm sure it's only a matter of time before someone gets punted up the rear by a 40 ton artic with serious consequences. Tesla need to sort this out quickly.

 

[Lchamp]

Mine seems to "panic" whenever someone crosses perpendicular in front of me...turning left or crossing or entering slowly from the edge of the road.

 

[LukeT]

Mis-reading of traffic in close proximity to main highway. Parked cars, cars in driveways.

I think for a fair observation you have to discount this one, because autopilot is specifically not for use on roads where there are lots of entries/exits other than proper controlled DC entries/exits. Whenever I use AP or TACC on anything else I don't expect it to handle a parked car on current software.

 

[Pagemakers]

Now it’s not just that. On a dead straight road with nothing in my lane my car now moves to the far side of the lane when passing something. Then it moves back. This causes a gentle and sometimes erratic ping pong uncomfortable drive, the likes of which were not apparent 6 months ago.

 

[Battpower]

I don't expect it to handle a parked car

That first point was ambiguous, sorry. The three or four cases I had in mind were on rural single carriageway roads at night, one with a long lay-by along side the road. Another was when I drove past a farm building with some farm equipment moving on the track near the main road. Not city driving. All dark, poorly lit but good visibility.

 

[Battpower]

car now moves to the far side of the lane when passing something.

Obviously not parked cars.... I get no response to them.

 

[LukeT]

That first point was ambiguous, sorry. The three or four cases I had in mind were on rural single carriageway roads at night, one with a long lay-by along side the road. Another was when I drove past a farm building with some farm equipment moving on the track near the main road. Not city driving. All dark, poorly lit but good visibility.

I've experienced similar, and do sometimes use it on some roads like this myself, my point of caution being just that it isn't (yet) designed to work on single carriageway roads.