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Autopilot scares the crap out of me!

2021 M3 LR with no radar running software version 2021.32.21, and autopilot is all but worthless. Admittedly, on city streets with lots of traffic, where it was probably calibrated in California busy rush hour traffic and where there is lots of sensory input, it does pretty well. But leave the city for more rural roads and the frequent, aggressive ghost braking makes it completely unusable. Driving from Moab to Salt Lake City on long straight stretches this weekend and about every 2 miles it would quickly decelerate from 75 to 35. Sometimes there was a truck coming the other direction, in its lane, not over the line, and posing no threat. But sometimes there was absolutely nothing! This was basically in the middle of the desert. I've had this issue on freeways in Utah, Idaho and Oregon as well. If the road is rolly-polly (even with biggish, smooth hills) and there is little or no other traffic, Autopilot completely freaks out when it gets to the crest of a hill and cannot see over the other side, suddenly slamming on the brakes and scaring the crap out of me and my wife. Note to Tesla engineers: THE EARTH IS NOT FLAT. This happens both with autosteer, which I don't use very often, and with me steering. It was an issue with 2021.4.21.3 and I was hoping it would get fixed with 2021.32, but it's no better. I really wish that the Tesla just had plain old vanilla cruise control, even non-traffic aware -- just set the speed and the car maintains that and I'll take responsibility for not rear-ending the guy in front of me. The 2010 Mazda 3 that the Tesla replaced had "dumb" cruise control like that, and I would take that reliability over the buggy-phantom-brake-I'm-going-to-need-more-Tide-pods-to-clean-my-soiled-underwear Autopilot. I really like a lot of things about the Tesla, but not being able to use cruise control/AP on long road trips is a huge disappointment. My fear is that it's going to unexpectedly brake hard with someone behind me and I'll get rear-ended. So, I'm going to quit trying to use it. Does anyone else with a non-radar 2021 M3 or MY have this issue? Edit: I paid the $200 for a month of FSD to see if it works any better with that, but it behaves exactly the same.
 

srs5694

Active Member
Jan 15, 2019
1,276
1,596
Woonsocket, RI
2021 M3 LR with no radar running software version 2021.32.21, and autopilot is all but worthless. Admittedly, on city streets with lots of traffic, where it was probably calibrated in California busy rush hour traffic and where there is lots of sensory input, it does pretty well. But leave the city for more rural roads and the frequent, aggressive ghost braking makes it completely unusable.
This is a long-standing complaint about Autopilot. It sometimes misinterprets overpasses as threats or reacts strangely to passing trucks, in particular. Note that Autopilot is NOT intended for use on city streets; it's intended for use on highways. The Full Self-Driving (FSD) feature that so many are discussing so fervently is intended for use on city streets, but not the stock Autopilot that comes with all Teslas today, or even the FSD package that provides a few extras on top of Autopilot but not yet the feature-complete FSD.

Personally, I've rarely encountered this phantom braking on my car, which I've owned for 2.5 years, with the exception of braking for cars that are trying to merge at an on-ramp -- it'll often brake when I'm driving in the right lane and the car in the on-ramp is ahead of me but traveling much more slowly than me. I've taken my car on several road trips, mostly through New York or Pennsylvania and into Ohio, from my home state of Rhode Island. I have noticed an increase in this problem recently, though, so maybe Tesla's been tweaking things in such a way that this particular problem has gotten worse. This sort of thing happens from time to time. Tesla's driving automation functionality is still under development, and sometimes improving one thing causes increased problems with another; but Tesla normally corrects the regression fairly soon.
 
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This is a long-standing complaint about Autopilot. It sometimes misinterprets overpasses as threats or reacts strangely to passing trucks, in particular. Note that Autopilot is NOT intended for use on city streets; it's intended for use on highways. The Full Self-Driving (FSD) feature that so many are discussing so fervently is intended for use on city streets, but not the stock Autopilot that comes with all Teslas today, or even the FSD package that provides a few extras on top of Autopilot but not yet the feature-complete FSD.

Personally, I've rarely encountered this phantom braking on my car, which I've owned for 2.5 years, with the exception of braking for cars that are trying to merge at an on-ramp -- it'll often brake when I'm driving in the right lane and the car in the on-ramp is ahead of me but traveling much more slowly than me. I've taken my car on several road trips, mostly through New York or Pennsylvania and into Ohio, from my home state of Rhode Island. I have noticed an increase in this problem recently, though, so maybe Tesla's been tweaking things in such a way that this particular problem has gotten worse. This sort of thing happens from time to time. Tesla's driving automation functionality is still under development, and sometimes improving one thing causes increased problems with another; but Tesla normally corrects the regression fairly soon.
Thanks for the input. I do wonder how much the lack of radar affects what I experience relative to those with radar-equipped M3s. TeslaVision-only is nice in concept and I have respect for the power of AI and machine learning, and perhaps even the increased frequency of phantom braking that you have observed is related to AP re-learning across the entire fleet. I suppose on an optimistic note, it can only get better for me from here as smarter updates are pushed out.
 

drtimhill

Active Member
Apr 25, 2019
2,363
3,082
Seattle
2021 M3 LR with no radar running software version 2021.32.21, and autopilot is all but worthless. Admittedly, on city streets with lots of traffic, where it was probably calibrated in California busy rush hour traffic and where there is lots of sensory input, it does pretty well. But leave the city for more rural roads and the frequent, aggressive ghost braking makes it completely unusable. Driving from Moab to Salt Lake City on long straight stretches this weekend and about every 2 miles it would quickly decelerate from 75 to 35. Sometimes there was a truck coming the other direction, in its lane, not over the line, and posing no threat. But sometimes there was absolutely nothing! This was basically in the middle of the desert. I've had this issue on freeways in Utah, Idaho and Oregon as well. If the road is rolly-polly (even with biggish, smooth hills) and there is little or no other traffic, Autopilot completely freaks out when it gets to the crest of a hill and cannot see over the other side, suddenly slamming on the brakes and scaring the crap out of me and my wife. Note to Tesla engineers: THE EARTH IS NOT FLAT. This happens both with autosteer, which I don't use very often, and with me steering. It was an issue with 2021.4.21.3 and I was hoping it would get fixed with 2021.32, but it's no better. I really wish that the Tesla just had plain old vanilla cruise control, even non-traffic aware -- just set the speed and the car maintains that and I'll take responsibility for not rear-ending the guy in front of me. The 2010 Mazda 3 that the Tesla replaced had "dumb" cruise control like that, and I would take that reliability over the buggy-phantom-brake-I'm-going-to-need-more-Tide-pods-to-clean-my-soiled-underwear Autopilot. I really like a lot of things about the Tesla, but not being able to use cruise control/AP on long road trips is a huge disappointment. My fear is that it's going to unexpectedly brake hard with someone behind me and I'll get rear-ended. So, I'm going to quit trying to use it. Does anyone else with a non-radar 2021 M3 or MY have this issue? Edit: I paid the $200 for a month of FSD to see if it works any better with that, but it behaves exactly the same.
Did you perhaps miss the bit in the owners manual that warns that TACC/Autosteer/AP are designed for use on freeways and divided highways and NOT on the roads you imply you are driving on?
 
Did you perhaps miss the bit in the owners manual that warns that TACC/Autosteer/AP are designed for use on freeways and divided highways and NOT on the roads you imply you are driving on?
From the 2021 M3 owner's manual: "Traffic-Aware Cruise Control is primarily intended for driving on dry, straight roads, such as highways and freeways. It should not be used on city streets." I think that U.S. highway and freeway system, which I mention in my post, qualify. Perhaps in your mind Utah roads are no more developed than the single-lane strips of pavement from the old Road Runner cartoons, but believe me they are well-maintained with good lane lines and traffic signs, and usually dry and straight. In fact, it would be hard to find better candidate roads for AutoPilot. Your suggestion that highways need to be divided, i.e. no oncoming traffic, for TACC to be employed, emphasizes my point about the un-usability of the technology. But heaven forbid that anyone would criticize Tesla; if the car is misbehaving it must be the fault of the owner.
 
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EVRider-FL

Active Member
Aug 18, 2015
1,263
750
South Florida
Autosteer works pretty well for me, on both freeways and rural highways, in my radar-equipped 2018 Model S. I’m on a road trip now and haven’t seen the issues that the OP (and others) have reported. Not saying others aren’t having issues, but not all of us are seeing them. The Tesla firmware has always been somewhat nondeterministic, in that two cars with the same configuration and firmware can behave differently under the same conditions.
 

drtimhill

Active Member
Apr 25, 2019
2,363
3,082
Seattle
From the 2021 M3 owner's manual: "Traffic-Aware Cruise Control is primarily intended for driving on dry, straight roads, such as highways and freeways. It should not be used on city streets." I think that U.S. highway and freeway system, which I mention in my post, qualify. Perhaps in your mind Utah roads are no more developed than the single-lane strips of pavement from the old Road Runner cartoons, but believe me they are well-maintained with good lane lines and traffic signs, and usually dry and straight. In fact, it would be hard to find better candidate roads for AutoPilot. Your suggestion that highways need to be divided, i.e. no oncoming traffic, for TACC to be employed, emphasizes my point about the un-usability of the technology. But heaven forbid that anyone would criticize Tesla; if the car is misbehaving it must be the fault of the owner.
Yes, it does mean divided highways, as has been discussed many times in threads on this site. Heaven forbid that anyone should dare to disagree with you.
 

chengka

Member
Dec 6, 2019
127
123
Denver, CO
OP, I feel your pain. I have a 2020 MY with Radar and there are may freeways around Denver, where TACC will slow from 70 to 50, FOR NO REASON WHATSOEVER, but it is very consistent, so whatever it is, is "intentional". Perhaps its shadows, overpasses, whatever, but its my biggest disappointment in Tesla. Honestly I've driven "dumb" cars with much better adaptive cruise control. The seconds biggest disappointment in being a Tesla owner, is the fanboys who answer all questions, observations, criticisms with "never happened, read the manual, you're not using the car as intended".

Cancel the $200 subscription and hope for improvement in the the implementation. Don't listen to anything EM says about FSD, its all aspirational at best, and fraud at worst.
 
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Apr 13, 2021
333
448
Colorado
OP, I feel your pain. I have a 2020 MY with Radar and there are may freeways around Denver, where TACC will slow from 70 to 50, FOR NO REASON WHATSOEVER, but it is very consistent, so whatever it is, is "intentional". Perhaps its shadows, overpasses, whatever, but its my biggest disappointment in Tesla. Honestly I've driven "dumb" cars with much better adaptive cruise control. The seconds biggest disappointment in being a Tesla owner, is the fanboys who answer all questions, observations, criticisms with "never happened, read the manual, you're not using the car as intended".

Cancel the $200 subscription and hope for improvement in the the implementation. Don't listen to anything EM says about FSD, its all aspirational at best, and fraud at worst.

On some stretches of 2 lane roads in Colorado mountains I have the same experiences as OP. I just ended up hover my foot over the accelerator (which is not ideal as the car will not brake when you do this). I have a May 2021 MY Vision Only so glad to hear the radar folks have the same issue. Fortunately it doesn't happen very often, I've seen it the most on the road from Silverthorne to Kremmling primarily and never on multi-lane highways.

I also agree the Tesla fanboy gaslighting is super frustrating in this thread and everywhere else. Look at the first two replies to this thread! What a bunch of idiots.
 

TLej

Little-Known Member
Dec 29, 2015
553
557
Edmonton, Alberta, Canada
I really wish that the Tesla just had plain old vanilla cruise control, even non-traffic aware -- just set the speed and the car maintains that and I'll take responsibility for not rear-ending the guy in front of me.
I would love to get dumb cruise control back, don't understand why it's not an option. My wife's last two Volvos have had both TACC and dumb cruise and you can switch between them as you like. It would be especially helpful for when a sensor gets blocked by a bug, snow, mud, sunlight, etc. and the system bails and leaves you driving in full manual like it's the '60#.

I have had the same experience with Autopilot, and with TACC. Autopilot makes me swear at the car frequently, when it happens on TACC it makes me unreasonably angry since the solution is so simple.

My last trip on AP was much better, so maybe it is learning and improving after the recent software update, but I would still love to have regular cruise and just enjoy the drive for a change instead of waiting for the car to do something dumb. The fact it doesn't warn you before it does something dumb just makes it worse.
 
It scares me too and my wife won't drive it.

I don't use autopilot. One evening a deer jumped on front of my car. I had to jam the brakes to stop and missed it by inches. I got no warning. Then the next morning, with no traffic near me (luckily) the car automatically jammed the brakes. Nothing was near except possibly a mosquito
 
I agree with a earlier comment that it's too bad there isn't just a basic cruise control. Nearly all our driving is on 2 lane country highways where nearly every large approaching truck causes sudden braking. It makes the current Autopilot Traffic-Aware Cruise Control not as usuable as cruise in a regular car. Plus here in Canada all traffic has DRL, so day and night all traffic's headlights are on and seem to add to add to ATAC triggering sudden braking.
 

Fernand

Active Member
Mar 22, 2019
1,642
1,847
Northern california
Its very important to distinguish the different feature sets and identify what you're talking about in posts. Because of confusing descriptions and feature creep we often end up talking past each other. Which Autopilot?

AP that comes with all teslas is a lane keeper with a somewhat smart cruise control. That's all. You can squeeze a bit more out of it but that's a bonus crap-shoot. No point in expecting more and talking about shortcomings of AP when using it beyond the intended domain.

Sandy Munro was saying AP does worse in subdivisions. He doesn't understand that the base AP knows nothing more than keeping in its lane, and just does a crude job of lane-keeping on all City streets.

EAP was offered until 2019 for about $5K and adds NOA (self navigate on autopilot on freeways, from onramp to final offramp) with self-initiated and on-request lane changes, freeway switching. And limited summon and auto-park.

Personally, I've gotten good at using NOA 95% of the time on freeways, disabling it briefly in anticipation of problem spots. Very useful. Those are also the (only) currently functional features of the "FSD" package.

The FSD option at ~ $10k gives the abovementioned EAP features, the new HW3 computer for those who didn't have it. And the promise of NOA on city streets. That part is the "FSD beta" that is currently in early beta for a limited group of testers, and so adds no mature functionality.

I think anyone who still has EAP, and is interested only in functionality, should stick to it for now, as you get nothing more that's helpful with "FSD" until NOA on city streets is more polished.

People who only have the base AP should say so, if they want to discuss the fine points of using it beyond its intended capabilities.

People who want simple cruise control can disable Auto Steer and some other settings.
 
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For an easy drive, I find the FSD early beta (2021.36.5.3 as of now) to be quite delightful!

If you aren't in the mood for babysitting (or testing as they call it), engage AutoPilot without a destination! Perfect cruise control! It handles all lights, stop signs, traffic speeds, etc. It'll change lanes on command, always easily and cautiously (talk about extreme blind-spot safety). It always adjusts correctly up and down for speed limits as well!

PS - the Autopilot on Navigate button doesn't work for me off-highway, so to place the Tesla in easy-FSD mode -- only using your lane changes and paying attention to all traffic laws -- you can't put in a destination. Hopefully, the next update will allow destination and respect the turning off of 'Navigate on Autopilot' on the fly.
 

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