Hard braking with TACC in stop-n-go traffic

[scottf200]

Not sure if others are seeing a big improvement is this problem. I get it occasionally but the ratcheting noise has significantly been reduced with recent software it seems. Currently on 2018.42.2 when I didn't notice it happening in a consistent way that I used to. I don't know when it significantly changed tho.

 

[boonedocks]

Happens much worse for me using EAP than TACC oddly enough. Even had major brake work dive and no help ¯\_(ツ)_/¯

It definitely is the mechanical brake pedal portion because if you place your toe under the pedal while these occurrences happen it mitigates it completely. Still is spastic braking but the “thud” sound is lessened dramatically

 

[thatisug]

Happens much worse for me using EAP than TACC oddly enough. Even had major brake work dive and no help ¯\_(ツ)_/¯

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It definitely is the mechanical brake pedal portion because if you place your toe under the pedal while these occurrences happen it mitigates it completely. Still is spastic braking but the “thud” sound is lessened dramatically

Good to see folks are still trying to get this fixed, still drives me nuts. Albeit I have just accepted that my brake pedal makes fart noises when using EAP and TACC.

I have noticed that Loaners I get have the noise as well (even newer 2018 models). I gave up with the service center trying to fix this one.

 

[ucmndd]

Happens much worse for me using EAP than TACC oddly enough.

I can definitely corroborate that. It's a very common occurrence for me with autosteer engaged in moderate to heavy traffic. Relatively rare with just TACC.

 

[Cirrus MS100D]

Put me in the same camp of "I know it's the brake pedal as I can feel it with my toes when it's happening" (I exclusively wear flip flops for 8 months out of the year...) Something I THINK I am noticing, but could be totally crazy, is that the "Brake Hold" (HOLD) is becoming a bit more difficult to engage at stop lights. I feel like a year ago, it was a nice, short, simple-but-firm press to get it to HOLD. Now, I feel like I have to apply a lot more pressure and sort of hold it there for a bit longer, and even then, occasionally, it won't engage. (I also don't get to drive the car that often- my wife says it's the same as it ever was, so it could just be the difference of me confusing the way it feels with my 500e).

 

[SeminoleFSU]

Good job with the Vids!! That is the exact same sound/issue I have been experiencing as well!

Ditto! Yea (hopefully) safe to say this is the brake pedal.

 

[Cirrus MS100D]

@boonedocks commented in the 48.1x firmware thread that he believes this has been dramatically reduced on his car with the latest firmware.

I drove home last night in about 20 min of heavy highway stop and go traffic and also would believe this to be similar for me, though I need a few more days and specific situations to be sure it’s not just placebo.

 

[quickstrike12]

@boonedocks commented in the 48.1x firmware thread that he believes this has been dramatically reduced on his car with the latest firmware.

I drove home last night in about 20 min of heavy highway stop and go traffic and also would believe this to be similar for me, though I need a few more days and specific situations to be sure it’s not just placebo.

No it’s real. I have been putting some miles on my S with the latest update. It’s not perfect and still makes the noise and stops a bit too abruptly sometimes. But it is definitely better than it was.
It’s getting there.
It seems like it needs to “widen” the margins or thresholds for the distance it keeps from cars ahead. In other words it’s ok to roll up a bit closer as you slow gently. Maybe just going past it’s “follow” distance a bit.
Of course i guess the truth is a human can see ahead and pickup clues as to what’s about to happen so we start to anticipate the braking. Brake lights, several cars ahead for instance. Would be awesome if the AP could see brake lights and start to use that information to help drive more like A human.

 

[Kruegmeister]

Settings 1 & 2 Brake Harder. 3 for me is smooth.
I use 1&2 sometimes but typically use 3 in Stop & Go, but I also hit the accelerator from time to time at Start since it takes of like a Grandma (This Needs to be a Setting, or more Aggressive in Ludicrous)

 

[quickstrike12]

Settings 1 & 2 Brake Harder. 3 for me is smooth.
I use 1&2 sometimes but typically use 3 in Stop & Go, but I also hit the accelerator from time to time at Start since it takes of like a Grandma (This Needs to be a Setting, or more Aggressive in Ludicrous)

I may try that(setting 3). I don’t typically go that high because here in Dallas Fort Worth we can get shot for leaving large gaps between cars in stop and go traffic and not getting moving quick enough.
Lol but I’ll give it a try.
I’ve always thought AP does a decent job but drives like an old lady. For aggressive driving styles(impatient like me) it isn’t as good in big city traffic.
Just my 2 cents

 

[StealthP3D]

I don’t typically go that high because here in Dallas Fort Worth we can get shot for leaving large gaps between cars in stop and go traffic and not getting moving quick enough.

Well, I hope self-driving systems never become so "intelligent" that they are capable of getting road rage! Which only serves to highlight how frustrated people must be (over unrelated things) for getting upset over such inconsequential things.

 

[quickstrike12]

Well, I hope self-driving systems never become so "intelligent" that they are capable of getting road rage! Which only serves to highlight how frustrated people must be (over unrelated things) for getting upset over such inconsequential things.

You are correct. We all need to take a moment and remember what’s important.
Happy holidays

 

[Cirrus MS100D]

Just to be clear, there is a big difference between the behavior of TACC and the “human-like / robotic-like” smoothness and the brake pedal juddering like ABS on steroids on a dry road in the summer going 40mph.

 

[ModlS3XY]

Here's a video of thes sound from my June 2018 MX.
Is there no solution for this?

 

[thatisug]

Here's a video of thes sound from my June 2018 MX.
Is there no solution for this?

No fix that I am aware of. Just kind of got used to the noise at this point. Service center informed we that it was ‘normal’.

 

[boonedocks]

No fix that I am aware of. Just kind of got used to the noise at this point. Service center informed we that it was ‘normal’.

I found a fix that worked 100%.

Upgrade to a Model S Raven. I guarantee it fixes this!!!

 

[TampaRich]

Here's a video of thes sound from my June 2018 MX.
Is there no solution for this?

Sounds like you have fart mode enabled.

 

[RonaldT]

I just got my car back tonight. I haven't had it long enough to be able to test if the repairs they did actually fixed anything. Hopefully tomorrow I'll be able to test that. The main thing they did was:

Corrections: Spring and Damper Assembly - Front - RH
replaced the Spring and Damper Assembly - Front - RH
FRONT COIL SUSPENSION MODULE - DM - Qty 1
S2 (1030607-01-D)
Parts Replaced or Added

Corrections: Spring and Damper Assembly - Front - LH
replaced the Spring and Damper Assembly - Front - LH
FRONT COIL SUSPENSION MODULE - DM - Qty 1
S2 (1030607-01-D)
Parts Replaced or Added

The tech said that they basically replaced the whole front suspension.

When I dropped the car off to have the problem looked at, I emailed them the links to those videos above. They seemed happy to get them.

I am wondering if this fixed the thumping brake pedal noise?

 

[sevenout]

I am wondering if this fixed the thumping brake pedal noise?

No! Made no difference at all. We have determined since that the noise is actually the brake pedal vibrating due to TACC pulsating the brakes.

 

[Mojito]

I get a clank metal noise for the first time when I let go of smart summons and came to a sudden stop never had I heard this Clank noise from my M3 front end.