What are you using to monitor the OBDII data stream? An off-the-shelf dongle and smartphone app? Looking for recommendations for 2023 M3LR. Or some home-brew device? I am thinking about building an Arduino or Teensy-based CAN bus reader for OBD with a real-time clock and accelerometer to try and log these type of things. I would also like a battery temperature read out and maybe a bright large LED display with P, R, D or Neutral until driving EV becomes habit.
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Major Phantom Braking Issues
- Thread starter LucLamma
- Start date
Could you elaborate why this pic indicates "pretty hard" PB? Is it because the full length green line indicating maximum regenerative braking??
sleepydoc
Well-Known Member
Full Strength regenerative braking is reasonably hard braking. It’s not slamming on the brakes by any means but if you’re driving on an open road and suddenly the car brakes that hard it catches you by surprise, makes for an unpleasant ride, triggers a momentary panic that tehre’s something in the road you missed and most of all is totally unnecessary
I am using a USB OBDII device, OBDII adapter and ScanMyTesla app on my smartphone.
Yes, I'm referring to the length of the green line but "max regen" braking isn't really the full story here as it is braking harder than the normal max at the same speed. Top pic is from a PB, bottom pic is from foot completely off the throttle regen during normal driving. The line is fuller during the PB event, which makes sense because the braking is very noticeably harder.
I was 99% sure it was braking harder than "full regen" but just made it 100% by going out and testing it and comparing.
sleepydoc
Well-Known Member
It really doesn’t matter except for people who want to divert the discussion and create strawman arguments. Regardless of whether it’s full regeneration or physical brakes on top of that it’s a significant deceleration that is unnecessary and makes for an unpleasant ride; it’s a defect in the system.
On a single 25mi trip this weekend I had two complete stops (0 mph) in the traveled portion of road with no warning or reason. One was with a vechicle behind me that almost hit me. The other was with no one behind me and it sat there for 2-3 seconds before proceeding. Neither actually qualified as a disengagement, but both were dangerous. 11.4.3
Just so people have some rough numbers here... The bottom(foot off the pedal) is about 65kW regen, and the top picture(strong PB) is approximately 75kW regen. The only caveat I would add in here is that the pictures don't tell the tail of the beginning of the deceleration curve. I have experienced the stronger regen, I just haven't captured it yet on SMT. It is a stronger regen with NO physical brakes but I am just going to guess that the beginning of that regen curve is going to be like what the normal regen curve used to be.
I was under the impression that only the length of the line indicated the degree of regenerative breaking or battery drain.
clydeiii
Member
I have these sorts of things on my commute: three different intersections this happens. It’s like the car thinks there is a stop sign, as it behaves exactly as if that were the case (though it never says braking for stop).
Happens on both my car and my wife’s. The oddest thing is, about a month into 11.3.6, our cars stopped doing this, miraculously. Like they pushed some hidden map update or something. Then a few weeks after that, before I got in 11.4.x, the cars both reverted back to their original habits and now both brake unnecessarily for these imaginary stop signs.
I report all three constantly.
My 2023 Model X has the new phoenix radar and I am having horrible phantom braking events on the highway. This is my first Tesla and the only reason I got this vehicle was because of the HW 4 and radar that was supposed to make things safer from what I have read but it still hasn’t been addressed. Seriously having long term doubts about my purchase because it been pretty scary. Never had these issues in my EV6 or Toyota Sienna
zoomer0056
Active Member
I have a Feb 2022 MSLR. There were two PB events in the first week of using TACC. Well, they weren't really phantom. One event broke hard for a cyclist riding safely off the road. The other was a hard brake for a vehicle parked safely off the road. Then I read the manual which says TACC is for controlled access roads ... highways. So no more TACC use on two land roads. I hate it when people don't read the manual! Anyway, I've not had anymore PB, or even phantom PB events since. Not because I read the manual, but because I've never used TACC since. The car is a dream to drive if you're not anxious about what it might do, a dream. Best car I've ever owned.
I drove to Colorado from Dallas last week and no phantom braking except for the travel between Clayton, NM and Dalhart, TX. It was terrible. It was braking every mile.. It happened both ways. I just kept my foot on the accelerator pedal and kept nudging it to go on everytime it braked.
@teslaai needs to test their FSD/AP on this road.
@teslaai needs to test their FSD/AP on this road.
I have experienced the same thing recently. We have a 2020 Model 3, LR, and I love the "cruise control;" and generally have no problem with it. But just recenlty--like over the last several weeks--I have experienced aggressive slowdowns on the highway with no apparent reason. It just happened again today and there was nothing nearby that the car should have been reacting to. I intend to call our Service Center tomorrow.
gulbranson
Member
The phantom breaking is a real problem on my 2023 MX HW4 (delivered in May). While on AP OR cruise the damn thing will randomly initiate a rapid deceleration. We just got back from a 450-mile trip and it did it 8 times! On 2023.26.6. My 2018 HW2.5 also had phantom breaking issues but has gotten much better over the last two years of ownership. It rarely, if ever, phantom breaks. With all the other "issues" (front doors don't open all the way, stupid placement of the horn button, drive motors that whine) I'm really starting to wish I'd not purchased a new MX!
Went on a trip to CA last month and had several phantom braking incidents. One hit the brake pretty hard and almost caused me to get rear ended.
Any way I can switch off the vision stuff and switch it into dumb cruise control mode?
Edit: Welp, reading more of these posts, looks like no dumb cruise control available. Looks like my car doesn't have a working cruise control anymore (I don't trust it).
Any way I can switch off the vision stuff and switch it into dumb cruise control mode?
Edit: Welp, reading more of these posts, looks like no dumb cruise control available. Looks like my car doesn't have a working cruise control anymore (I don't trust it).
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which likely means HW4 doesnt include a radar unit - or - it's not used for AP/TACC as an input?
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