Forums

2 days ago when drving on freeway model x was stopping when set to Adaptive cruise control

2 days ago when drving on freeway model x was stopping when set to Adaptive cruise control

hi
did anyone experience this after newest software update my car was decreasing speed itself when it was set to 70miles per hour Adaptive cruise control.
i have autopilot in my car

please let me know
thanks

seamaze | 1 April, 2019

I had been observing this since 2019.5.15. Increased amount of phantom braking and even sudden braking during my daily commute which I haven’t experienced before. I am just waiting for new update to correct this. In the meantime I have become extra careful while using TACC.

dewittbo | 3 April, 2019

I have noticed three things similar to this: my X stops farther away from the car in front at stoplights than it used to, it will brake unexpectedly for no apparent reason, and it is more sensitive to cars either crossing in front of it or turning in front, braking aggressively in both cases.As a result, I engages TACC less often now since I trust it less. I hope some tweaks will be sent out to modify this behavior.

keiki | 4 April, 2019

Just got 2019.8.4 yesterday. Now it slows down and speeds back up with Adaptive Cruise set to highway speed. More of an intermittent jerking of car like brakes on, brakes off. Adaptive cruise is almost unusable. Never experienced this in the previous 2 years.

lilbean | 4 April, 2019

I have been thinking since Joshua Brown, that it is supposed to be unusable so that people won’t use it and blame Tesla for accidents. Mine has been unusable since then.

lpjakob | 15 April, 2019

Drove Los Angeles to Rancho Mirage yesterday in our 2017 MX 100D, software 2019.8.5 using Navigation on Autopilot. I had four sudden slow downs for no reason in which I had to take over and step on the accelerator. I also have M3P+ with same software and drove 1,600 mile round trip Southern CA - Nevada - Arizona - return with no mystery breaking. Both cars have FSD from original factory order. I believe MX has hardware 2.0; M3 has 2.5. MX has always had the strange breaking behavior but this was the most I have ever had on any trip. M3 has never had this problem. Both cars will be getting free upgrade to new FSD computer, will need to see if this problem is corrected in new software or new hardware.

eveningsun | 15 April, 2019

was having both gradual and hard breaking on MX HW2.5 recently as well (on top of other issues like reboots in the 2019.8.5 update)

jjgunn | 15 April, 2019

Noticed some braking as well. Easily rectified by gently pressing the accelerator.

The car believes certain areas have reduced speed limits (incorrectly). Noticed it on 101 Southbound in SF right about hospital curve as you're heading through the city.

I have MX 100D June 2018 (HW 2.5)

RT_TMX | 6 June, 2019

I have experienced the same. Multiple times on 101S in the Bay Area. Mostly close to over passes. The speed suddenly slows and then speeds and often brakes suddenly. This is very dangerous. A couple days ago I was on AP at 65 mph on a 65mph zone. Suddenly AP thought the speed limit was 15 and hard braked. I think it picked up a sign on the bridge that said the height was 15 feet and thought it was the speed limit. AP will cause havoc with this bug. Tesla knows this and is doing nothing.

deanzsyclone | 9 June, 2019

My freshly Jun 2019 delivered X has done this like three times on me. Once on the freeway 101, from 65mph very quickly down to 40mph. Nothing in front of me.