Startled by computer taking over braking [Automatic Emergency Braking]

[gearchruncher]

Unfortunately AEB triggers falsely on occasion.

My early 2018 Model 3 never once triggered AEB wrongly (though I have gotten a few forward collision warnings)

We're back into this discussion. There's people that argue it's not phantom braking if you can identify why it braked even if it shouldn't. Others define it as any braking that should not have happened. Some of this is actual AEB (chimes, message on display) some of this is just slowdowns on AP. People have discussed this ad-nauseum, with one group claiming phantom braking is just TSLAQ FUD (despite Elon tweeting about it and Tesla pulling software versions for it), the others claiming it's a huge issue with Tesla's system. It is clear that people have very different experiences.

Not wanting AEB turned on because of phantom braking is very different than believing you are a statistical outlier and you don't need it at all. As a note, phenomenal drivers can override phantom braking with a stab at the throttle.

 

[gearchruncher]

Then there's two winners. I had the same thing happen to me and now my brakes are warped.

You're claiming AEB warped your brakes in a Model 3P? And what you are annoyed at is AEB, not the totally crap brakes Tesla put on your car if this is true?

 

[CarlThompson]

We're back into this discussion. There's people that argue it's not phantom braking if you can identify why it braked even if it shouldn't. Others define it as any braking that should not have happened.

Hmm... I was assuming that phantom braking on AP and AEB which happens even without AP are completely separate phenomena.

 

[gearchruncher]

I was assuming that phantom braking on AP and AEB which happens even without AP are completely separate phenomena.

It's the same computers, sensors, and logic, so it's a very fine line between what is AEB and what is AP.
Remember when Tesla removed radar to go vision only? AEB was disabled for a while, and AP's capabilities were reduced. They go hand in hand. Distance and closure rate to the object ahead are not measured differently in the two cases.

 

[Knightshade]

Then there's two winners. I had the same thing happen to me and now my brakes are warped.

No they aren't. Properly installed, non-defective, rotors don't warp from use, even heavy use.

What you've got (if you've got anything) is uneven pad transfer. If you wanna read the best debunking of the warped rotor myth I've seen (though there's plenty of others out there) I suggest this, whose author had forgotten more about braking systems than any 10 people on here combined ever knew (Carroll Smith)

https://centricparts.com/getmedia/bd69395a-b65c-481d-93f7-b26b1bd0638d/Centric_and_APC_Technical_Whitepaper_B1-Warped-Brake-Disc-8-2018_1.pdf

He also helpfully suggests a few ways to fix it, with no need to replace the rotors since they're fine.

 

[DayTrippin]

I've had too many phantom braking issues when TACC or AP is engaged but today was the first time I had an issue with AEB. I am not really sure what triggered. I was coming up to a stop sign at about 20 mph. About 30' from the stop sign it went to full emergency braking mode to the point of ABS engaging.

Like all my other phantom braking, I was thankful there wasn't anyone close enough behind me to hit me. I have one of the radar less models Y's.

 

[gearchruncher]

What you've got (if you've got anything) is uneven pad transfer.

Just this weekend I had to aggressively come to a stop from 90 MPH, and stay stopped for 5 minutes. No pad transfer. Never had any pad transfer in a Model 3 despite lots of track miles. Really wondering how AEB even theoretically caused this in a single stop, which was apparently a false positive so the OP didn't even come to a fully stop, making uneven pad transfer basically impossible.

 

[firstkill]

In a few cars that I have the Nannies and the Tesla. It often gets activate when you get cut off.

Merging on and off the freeway. People never line up in the traffic. And be nice. They will speed up in the adjacent lanes and cut in at the last moment.

 

[CarlThompson]

It's the same computers, sensors, and logic, so it's a very fine line between what is AEB and what is AP.
Remember when Tesla removed radar to go vision only? AEB was disabled for a while, and AP's capabilities were reduced. They go hand in hand. Distance and closure rate to the object ahead are not measured differently in the two cases.

They MUST be different simply because AP phantom braking is MUCH more common than AEB braking. I have seen phantom braking for things like bridge shadows which NEVER cause an AEB event when AP is off. It's not the same.

 

[Ren.OG]

You're claiming AEB warped your brakes in a Model 3P? And what you are annoyed at is AEB, not the totally crap brakes Tesla put on your car if this is true?

Both are annoying. If AEB didn't activate my rotors would still be fine. BUT if AEB didn't activate I wouldn't know I had susceptible rotors until later, maybe after warranty expires. oh well, hopefully my SC will repair/replace under warranty.

 

[VanGuy]

I'm using the auto safety features to force me to be a more chill driver. It's freaked me (and the wife, ugh, the wife aggro) a few times in very similar instances. But if I am honest, I shouldn't have been so close and been giving more room. Same as you, it was for sure "fuzzy". If someone is following too close to us and dings us, well, that's on them and we'll have to live with it.

 

[gearchruncher]

Both are annoying. If AEB didn't activate my rotors would still be fine. BUT if AEB didn't activate I wouldn't know I had susceptible rotors until later, maybe after warranty expires. oh well, hopefully my SC will repair/replace under warranty.

You have a huge mod list, including the hope for bigger brakes (soon), and you're blaming AEB for "warping" your brakes?
How did AEB warp your brakes? A single stop from any legal speed does not warp brakes.
Is there a TSB on "susceptible" rotors from Tesla?

 

[Ren.OG]

My car is currently stock.
Yea rbbk and slotted fronts are a future purchase after they fix OEM rotors.

I was going about 10-15mph in stop-n-go traffic. Why are you in such disbelief that a single event can cause warping?

 

[Knightshade]

My car is currently stock.
Yea rbbk and slotted fronts are a future purchase after they fix OEM rotors.

I was going about 10-15mph in stop-n-go traffic. Why are you in such disbelief that a single event can cause warping?

Because non-defective, properly installed, brake rotors don't warp. Even under heavy track abuse.

See the white paper from Stoptech I posted earlier among a myriad of other sources regarding the warped rotor myth you're falling for.

And they sure as sugar don't warp on a stop from 10-15 miles per hour.

 

[gearchruncher]

I was going about 10-15mph in stop-n-go traffic. Why are you in such disbelief that a single event can cause warping?

OMG. The energy in a car at 15 MPH is 4% of that at 75 MPH. It will barely heat up the brakes.
I am in disbelief because brake system are so much more robust than that. They can handle ABS stops from 100MPH without damage. Via what process do you propose a single stop from 15 MPH can "warp" a rotor?

What are you expecting to get out of upgraded brakes if you think a 15 MPH stop can damage brakes? Anyone that has ever tracked a car knows that there is no damage you can do to brakes at 15 MPH, and the stock brakes are more than sufficient for any road use.

 

[Ren.OG]

Ok if yall don't want to believe that is your problem.
I'm literally just giving you what i've encountered so far.

Car activated AEB, after this my rotors are warped.
Done with yall.

 

[Knightshade]

Ok if yall don't want to believe that is your problem.
I'm literally just giving you what i've encountered so far.

You really aren't.

Because your story defies some basic laws of physics.... (maybe chemistry too? which one is metallurgy? )

 

[Marty3SR+]

Car activated AEB, after this my rotors are warped.

You could be right, because I'm no expert on brakes, but I've tested stopping on cars in the past without damaging the brakes, so it does sound unlikely.

However, I am an expert on logic, and your logic is faulty. It's like saying drinking water causes heart attacks. I know because someone I know had a glass of water, and then had a heart attack right afterwards. Proof positive!

 

[Ren.OG]

Ya'll are clowns rofl

I'm LITERALLY giving you what I've encountered.
IDGAF if you believe me or not with your logic.

 

[PDX-Y]

one of those "fuzzy" situations where yes, the car in front was stopping but the cars in front of THEM were moving again so they would have started to move forward in a second.. hence the slow stopping.. The computer disagreed and overruled me :/

So what you're saying is that you were driving in a way that was going to imminently collide with another car, on the assumption that they were going to move the way you expected them to?

The computer is right and you are wrong. What if they were on their phone? Lesson number two of defensive driving is to never place your safety on the assumption of another driver's behavior.

(Lesson number one is to never drive in ways other drivers don't expect, of course.)