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Adaptive Cruise Control Freaks out

Puma2020

Member
Jun 16, 2020
416
442
New Hampshire, USA
The Adaptive cruise worked great except for 3 cases where it freaked out. A bit unnerving, since the first 2 times, we were following a car on the highway at speed and the car in front took the exit lane and started to slow down. Nothing in front of my lane except for open road and the cruise freaked out and started to slow down dramatically. The other time was on a 2 lane road and a car crossed in front (safely) to go the other way the cruise freaked out momentarily because something was in front of it. It wasn't even close and a human (me) wouldn't have even flinched. In this case the car slowed down about 10 mph (50 to 40) until the car was deemed to be clear and accelerated again. Anyone else notice this?
Cars crossing or turning in front of the cruise tends to upset it even though it is fairly clear (to a human) that there will be no issue in a few seconds.
 

im4uttx

Supporting Member
May 28, 2019
363
225
Spicewood, TX
Yes, I've had similar cases..
Seems like the adaptive cruise is sensitive to vehicles moving into adjacent lanes and slowing (perhaps enough in the same lane that the car doesn't want to go by).
Also have cases where the red-light (green light) recognition is late and the car slows down before "accepting" the green light and continuing.
The car crossing in front has happened a couple times with automatic emergency braking...might adjust emergency braking sensitivity to late from medium.
 

frankvb

Supporting Member
Feb 29, 2020
901
553
San Diego, CA
Also have cases where the red-light (green light) recognition is late and the car slows down before "accepting" the green light and continuing.
Not sure if that's exactly what you mean, but the car will always slow down and stop, even in case of a green light, unless you acknowledge the traffic light message with the right stalk or by tapping the accelerator.

Only in the latest software that is changed, and it will continue by itself in case of a green light, but only when you are following another vehicle.

On the freeway, if there's a (very) slow vehicle in the adjacent lane, TACC will slow down while passing it.
 
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im4uttx

Supporting Member
May 28, 2019
363
225
Spicewood, TX
Not sure if that's exactly what you mean, but the car will always slow down and stop, even in case of a green light, unless you acknowledge the traffic light message with the right stalk or by tapping the accelerator.

Only in the latest software that is changed, and it will continue by itself in case of a green light, but only when you are following another vehicle.

On the freeway, if there's a (very) slow vehicle in the adjacent lane, TACC will slow down while passing it.
Yes, with the latest software it no longer requires acknowledgement, in some cases, but I've had it do strange things, even with the latest software release, depending on how close the car is in front of you. Sometimes the car in front will accelerate faster away from a new green light, then what seemed to be the Y needing an ack before proceeding...better than being forced to ack every time, but still not perfect yet.

Also, I haven't had the case of the light changing as cars in front are going through to see what the software will do...does it stop at red light or do we need to intervene?
 

frankvb

Supporting Member
Feb 29, 2020
901
553
San Diego, CA
I'd prefer if there was no need for the acknowledge at all - after all that's exactly the same as if you disable the feature. It just means the only case you need to intervene is when the red light is not detected, but IMHO if the car fails to detect the traffic light state on time it could just give an audible warning. I don't really like the small warning on the screen as it's hard to notice without looking towards the screen, I'd rather keep my eyes on the road.

With the previous software version the car does stop if the light changes to orange after you do the acknowledge (unless you're too close to the light and it will just proceed). Have not experienced that yet with the latest software, another car being in front being a different scenario.
 

TomServo

Active Member
Apr 10, 2014
1,349
898
Belleville IL
The ACC on our 2017 Volt does the same thing, I was hoping TACC as implemented in a Tesla would be much better. Can't wait to see for my self, I hope it's better.
 

im4uttx

Supporting Member
May 28, 2019
363
225
Spicewood, TX
The ACC on our 2017 Volt does the same thing, I was hoping TACC as implemented in a Tesla would be much better. Can't wait to see for my self, I hope it's better.
It's not bad, and I wonder if part of the current issues reside in a change to TACC AI I think I was reading here somewhere...have to re-learn the basics to feed the new AI. Once all that gets up to speed, the TACC is going to be pretty good, imo. I love it, but hate having to wonder if it is going to slow/stop at a green light because the vehicle in front is too far away...but with the number of cars on the road with the upgraded AI, I think it will come up to speed soon...I hope this is the case, anyway...
 
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kornelyus

Member
Jun 19, 2020
20
14
Penn Valley, CA
In my case ACC slowed down for a truck on the opposite lane, seems it thought the truck was on my lane on a collision course. Very dangerous, I could have been rear ended. Another case, car in front turning onto exit lane also caused the same false alarm. In 3 other cases, when there was no cruise control involved, as I was taking a curve, the car freaked out alarms blaring as if it I was running off the road, it slowed down and did a steering correction which wasn’t needed at all.
 

Ruffles

Member
Jun 13, 2017
426
605
Snohomish WA
My Model X with AP1 did the same thing. It is very conservative when deciding if a car has moved out of your way. It's common on the freeway when the car in front of you slows to take an exit and they have moved over enough for you to pass but AP still slows down until they have truly made the exit.
 

RandyByTheBay

Member
Jun 5, 2020
11
7
San Francisco
Two days ago, I was driving on I-5 a little over 70 MPH with TACC (not AP) and the car did a panic stop. I glanced at the display to see an indication of a traffic light and the message of stopping for traffic control (red light). I quickly hit the accelerator to override and continue (luckily no one was following closely or I would have been rear-ended). There was a traffic light on the frontage road off to the side of the freeway which must have triggered the traffic control. As much as I'm enjoying my MY, these false alarms at speed need to be resolved quickly, a panic stop at 70+ MPH on the freeway is very dangerous.
 

philw1776

Member
Jul 18, 2020
29
17
Seacoast, NH
In 3 other cases, when there was no cruise control involved, as I was taking a curve, the car freaked out alarms blaring as if it I was running off the road, it slowed down and did a steering correction which wasn’t needed at all.

My Y freaks out and issues the take over immediately alarm message when I am not in autopilot. Nothing around. One guess is that it loses sight of the road edge; I'm in the right lane of a 3 lane highway.
 

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