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Phantom Braking getting worse - any ideas on how to stop it?
- Thread starter Ev_Rider
- Start date
I wonder what people who keep saying they wish for "straight up cruise control" are thinking. Maybe they don't remember: straight up cruise control drives you right under that semi trailer in front of you, and decapitates you as you total your car. Unless they have those white and red striped gates that were put on trailers to keep you from decapitating yourself. You still total your car.
I have straight up cruise control on my pickup. You are always fiddling with it unless there's no traffic, or unless you manage to follow someone else using cruise control and you like their speed. Even then, TACC is much better.
I have straight up cruise control on my pickup. You are always fiddling with it unless there's no traffic, or unless you manage to follow someone else using cruise control and you like their speed. Even then, TACC is much better.
Well I’m not an idiot so I would not cruise control into the back of a semi. I have a Ioniq hybrid with straight cruise control that I’ve survived with for 5 years. And it doesn’t randomly slam the brakes on you while going 80 down the highway.
I'm not implying that you or me or anyone else that uses old time cruise control is an idiot. I'm saying that it's got significant risks. There's a good reason they put those low gates at the back of semi trailers.
You have to pay close attention no matter what. I have read that overall all versions of TACC (collectively) increase your risk of accident/death by 10% compared to non assisted drivers. I couldn't find the numbers, but I would bet that basic CC is much worse (which is why manufacturers are developing TACC, of course.)
Tesla TACC definitely needs improvement. You have to be ready for phantom braking. If you aren't willing to do that, the safest thing is to drive unassisted.
Never had a hard brake type of phantom braking, only slow downs that are always in the same spot in the relatively new revamp of the freeway. Also on a newly constructed beltway with very little traffic. speed limit was 70mph and TACC was limited to 30 mph for long stretches. mine was probably the first Tesla on that highway. I probably should look to see if that road is showing on Google maps or google street view. other than that slowdowns are related to vehicles cutting in front from side roads etc. BTW that slowdown on the freeway is near the former BMW dealer facility that is now a TESLA show room and service center. Hoo Wah!
We literally just now got back from our 4th of July trip to Taos/ New Mexico and I am *furious* at the performance of TACC and AP on this trip.
short version: TACC and AP in my 2019 Model 3 (2023.20.4.1) - castrated down to "vision only" - on hot/sunny days with plenty of mirages over the hot asphalt is one epic s**t-show with frequent and often harsh phantom braking ... suddenly going from 80mph down to 50mph on an open road with only few cars around because the car thinks there is something when there's nothing... fun ....
long version:
we drove from the DFW area to Taos NM via Henrietta - Quanah - Amarillo - Clayton on Friday June 30th and drove back today.
Going the drive was fairly uneventful with some rain north of Amarillo and - a few - modest phantom brakes between Clayton and Cimarron. 412 is a very isolate and empty road so I blamed it on that and while annoying it was manageable.
on the drive back today we started with some phantom braking on 412 going East to Clayton ... typically when mirages appeared over the hot asphalt and the road was going over hills and downhill. Wife had TACC set to 71 mph and the phantom braking was rather mild... taking us from 71 mph down to 60 mph and back up to 71 mph.
Clayton to Amarillo on hyw 87 is where the "fun" started... speed limit on the Texas side is 75 mph so I set AP (i prefer AP, wife prefers TACC) to 83 mph and experiencing the same situations - mirages over hot ashphalt but fairly empty roads - the car became very irratic ... we counted 5+ phantom braking events before driving manually to Amarillo. at time the car would brake so hard that we went from 83 mph down to 50 mph and remain at 50 mph for a few seconds before accelerating again. A car passing us on the other lane honked at us - probably thinking we had a stroke/ high or drunk....
After Amarillo on 287 down to Fort Worth the same thing again. multiple phantom brakes... some so harsh my wife freaked out and stated that next time we should take her Mazda CX5 if this is how it's going. Ended up driving most of the drive manual without TACC / AP. super fun on an 11+ hr roadtrip....
a few observations:
- around sunset without any mirages the phantom braking events disappeared altogether
- going ~70 mph or less produced fairly "modest" phantom brakes ... but 75 mph+ somehow tricked the car into applying the brakes HARD. Even worse going faster than 80mph...
- we drove the exact same route back in late May 2022 for Memorial Day weekend (with the radar enabled version) and experienced ZERO phantom brakes
if this is how AP / TACC behaves on warm/sunny days in Texas on long stretches of open road at a slight decline/ hilly ... then this is a no=go for me.
I REALLY like my car but this erratic behavior makes road-tripping very stressful and not enjoyable and is downright embarrasing when my wifes' 2020 Mazda CX5 handles TACC *just fine*.
I filed a service request with Tesla in the app and will also file a NHTSA complaint.
short version: TACC and AP in my 2019 Model 3 (2023.20.4.1) - castrated down to "vision only" - on hot/sunny days with plenty of mirages over the hot asphalt is one epic s**t-show with frequent and often harsh phantom braking ... suddenly going from 80mph down to 50mph on an open road with only few cars around because the car thinks there is something when there's nothing... fun ....
long version:
we drove from the DFW area to Taos NM via Henrietta - Quanah - Amarillo - Clayton on Friday June 30th and drove back today.
Going the drive was fairly uneventful with some rain north of Amarillo and - a few - modest phantom brakes between Clayton and Cimarron. 412 is a very isolate and empty road so I blamed it on that and while annoying it was manageable.
on the drive back today we started with some phantom braking on 412 going East to Clayton ... typically when mirages appeared over the hot asphalt and the road was going over hills and downhill. Wife had TACC set to 71 mph and the phantom braking was rather mild... taking us from 71 mph down to 60 mph and back up to 71 mph.
Clayton to Amarillo on hyw 87 is where the "fun" started... speed limit on the Texas side is 75 mph so I set AP (i prefer AP, wife prefers TACC) to 83 mph and experiencing the same situations - mirages over hot ashphalt but fairly empty roads - the car became very irratic ... we counted 5+ phantom braking events before driving manually to Amarillo. at time the car would brake so hard that we went from 83 mph down to 50 mph and remain at 50 mph for a few seconds before accelerating again. A car passing us on the other lane honked at us - probably thinking we had a stroke/ high or drunk....
After Amarillo on 287 down to Fort Worth the same thing again. multiple phantom brakes... some so harsh my wife freaked out and stated that next time we should take her Mazda CX5 if this is how it's going. Ended up driving most of the drive manual without TACC / AP. super fun on an 11+ hr roadtrip....
a few observations:
- around sunset without any mirages the phantom braking events disappeared altogether
- going ~70 mph or less produced fairly "modest" phantom brakes ... but 75 mph+ somehow tricked the car into applying the brakes HARD. Even worse going faster than 80mph...
- we drove the exact same route back in late May 2022 for Memorial Day weekend (with the radar enabled version) and experienced ZERO phantom brakes
if this is how AP / TACC behaves on warm/sunny days in Texas on long stretches of open road at a slight decline/ hilly ... then this is a no=go for me.
I REALLY like my car but this erratic behavior makes road-tripping very stressful and not enjoyable and is downright embarrasing when my wifes' 2020 Mazda CX5 handles TACC *just fine*.
I filed a service request with Tesla in the app and will also file a NHTSA complaint.
johnnycnote
Member
Phantom braking, in my experience, is not braking, but a gradual slowdown of anywhere from 5mph to 10mph and usually on a highway. First, I make sure that it's not due to a specific reason that I might be missing, like a lower speed limit. if not, I just feather the accelerator a bit and things get back to normal.
Did a lot about 300 miles of traveling this week with no PB. I also had zero interventions on multiple trips and I didn't even realize it until after we got to the destinations.
Did a lot about 300 miles of traveling this week with no PB. I also had zero interventions on multiple trips and I didn't even realize it until after we got to the destinations.
Last July, I had similar issues driving on US287 and I-40 using NOA, so I understand your frustration. I even had Red Wheel of Death takeover notices on US287 when the AP computer crashed multiple times! I'm driving out there again soon on 11.3.6 FSDb and wondering how much improved (or not!) PB will be. Those were the worst roads I've been on for PB.
BTW, submitting a service request for this is a waste of time. There is nothing that a Tesla mechanic can do about phantom braking.
You're in New Jersey. He's in Texas. Folks out west have been reporting this sort of harsh phantom braking for a while now, often citing heat shimmer.
maybe not. But i want Tesla to at least be confronted with it and have it on record as a service log. Again - the performance of TACC (not even talking AP) is INSANE on hot days on long stretches of road with mirages.
If i cant use cruise control going pretty much just under 5 hours straight on a well built out highway with 2 lanes each direction - separated.... when can I use cruise control then? No other car with TACC struggles this much and brakes repeatedly this hard for *nothing*.
and the kicker: I drive this route pretty much annually on our way to Taos and *never* had this issue before they made my radar equipped car "vision only".
for now it's going to be back into the Mazda CX5 for long roadtrips in spring/summer/fall.... apparently TACC in the Model 3 only works reliably when the asphalt isn't hot (zero issues on our drive down to Galveston for NYE a few months back). The feeling out of the sudden going from 80mph+ down to 50mph would freak anyone out... including other cars honking at you.
When there is "heat shimmer," or mirages, there are almost always lots of them. If mirages are what causes them, there should be thousands of PBs per hour. So I think there's more to it. I certainly don't have the answer, but I find it interesting.
And maybe you are right. It's probably beneficial for Tesla to have an accounting of the number of complaints. Although the SC won't do anything, maybe Tesla will eventually get around to it, like they apparently have done (or will) with the wipers.
It's interesting that you associate an increase of PB with loss of radar. There are others that report they saw a decrease of PB events in spite of loss of radar. I have never had radar myself, so can't say, other than that PB has never been frequent enough for me to consider my car undrivable. And there's definitely less than there was a year ago.
And the other mystery to me is, why do some cars experience more than others in the same situation when they should theoretically be the same?
I got my car in August 2019 and during the "radar era" I experienced PB exactly *twice* at the exact same spot... rural road down to Possum Kingdom Lake where road dips under a bridge and car radar sees bridge / signs hanging on bridge as an object and applies the brakes. super corner case. otherwise - zero PB. Drove from Fort Worth to Lake Pend Oreille in Northern Idaho in August 2020 and ran TACC / AP nearly the entire time ... no issues whatsoever. In fact ... i couldn't have done that drive with the foot feathering the accelerator for days... Not sure how Subaru does it ("vision only" as well) ... but most other OEMs who offer TACC use radar units and perform just fine. In fact - the radar unit in my Model 3 is a continental radar used by VW and others. Before Elon decided to cut a few hundred $ and supply chain crunch and go without radar... but even then.... deleting the radar from all cars and making TACC / AP awful on hot summer days... not cool.
Somebody's ego getting in the way, as well as cost questions.
especially if project highland includes a radar again (...) I was near 100% certain that our next Tesla will be a Model Y AWD to replace the wife's Mazda CX5... but now definitely not if it doesn't include radar and can handle cruise control in the summer without freaking out. It's a shame because I really do not feel like paying a few $k extra just to get a Mach E which is inferior in other ways. But not being able to turn on cruise control and enjoy the drive without my foot getting sore is a dealbreaker...
Does anyone have these issues out west using FSDb? In general, my experience with FSDb has been very good with regard to PB. TACC and AP currently use very old code (by today's standards) and haven't seemed to have gotten much attention in the last year or so. I expect that eventually, these software products will be replaced by FSDb-derived software, though who knows when that might be. But, given that FSDb is beginning to be baked into the production software builds, it might happen this year.
If FSDb provides better PB performance on western roads in summer, a reasonable strategy for those making infrequent trips could be to subscribe to FSDb for a month when taking a trip. I'm doing just that for an upcoming trip, both for the convenience of FSDb as well as the hope of having fewer PB events.
If FSDb provides better PB performance on western roads in summer, a reasonable strategy for those making infrequent trips could be to subscribe to FSDb for a month when taking a trip. I'm doing just that for an upcoming trip, both for the convenience of FSDb as well as the hope of having fewer PB events.
lol. yeah ... let me pay $200 (!) whenever I take a road-trip so cruise control works like in any other car out there with traffic aware cruise control.... great pitch. God forbid Tesla finally restores cruise control / AP functionality to how it was *before* they software deleted radar on all vehicles...
for $200 it might be cheaper just to rent a car and put the mileage/wear and tear on the rental ... most rentals for $50+ / day to have TACC with radar sensors...
Better still might be to sell your Tesla and purchase something that doesn't infuriate you so badly. Life is too short for that.
Good luck in whatever you decide.
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