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Another Sudden Acceleration

Discussion in 'Model S' started by Omnomynous, Jun 25, 2019.

  1. Tam

    Tam Well-Known Member

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    It's reproducible every time for me.

    If my Model 3 is standing still with brakes on and there's a car in front anywhere including a parking lot, and I swipe quickly to Drive and again to make sure it's in Drive: That's a TACC but fortunately only at 18MPH.

    For those who are not expecting it, they may think this is an unintentional acceleration but the machine does what we asked it to do: 1st swipe down to go to Drive and again to TACC.


    [​IMG]


    If my Tesla moves above zero MPH and there's a car in front anywhere, even parking in a parking lot, it would allow TACC to the speed limit which in my case below as 70MPH:


    [​IMG]

    I have no problems with these scenarios because I know how to manually apply brakes as needed.
     
    • Informative x 2
  2. MrABRanch

    MrABRanch Member

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    Does it just lurch forward then stop - do you have a video, I know this makes sense but I also think it's a bug and could easily lead to an accident, shouldn't be so easy to have the car move forward suddenly, unexpectedly.
     
  3. Tam

    Tam Well-Known Member

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    #63 Tam, Jun 30, 2019
    Last edited: Jun 30, 2019
    From a full stop, it can only lurch to 18MPH when Model 3 owners trying to make sure the gear go to Drive by swiping down twice (because swiping down once may not get it sometimes).

    18MPH is not very high speed but because of the torque, it could scare the owner especially if it quicks the gravels up in the air.

    However, because it's in TACC, it does not collide with the car in front. It just go full speed from 0 to 18 MPH then it brakes!

    Again, that would scare an owner who thinks it is unintentional acceleration and might manually apply the brake but with the wrong pedal and in this case, the accelerator pedal would override the TACC and you'll get a collision for sure.

    However, if my Tesla moves beyond 0MPH and there's a car in front, it would allow maximum allowable TACC which in my case as 70MPH in the parking lot.

    It would lurch to match the speed from 3MPH to 70MPH toward the front car in its TACC mode but it will brake well before hitting the front car because that's the function of TACC.

    If you want to reduce the torque for the attempt to raise the speed from 0MPH to 18MPH or from 3MPH to 70MPH, you might want to go to the Driving menu and turn on "Chill" mode.

    It's not a problem if people know how to brake. It's a problem when people panic and apply the wrong pedal in automatic acceleration--no accelerator pedal pushed and the car still moves forward (as in 1/ TACC and 2/ creep)!
     
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  4. MrABRanch

    MrABRanch Member

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    I just think the car needs to have more safety with this possible accident, it's the situation where you're in 'H'old mode and then accidentally knock the stalk down into 'D' (which it is already in) this leads to a TACC event, that will be unexpected and yes, could lead to a sudden dangerous reaction from the driver...not sure what the solution is, except redesigning car with 2 stalks, which is what they should have done.
     
  5. Dr. J

    Dr. J Member

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    I agree, except that it appears not to be bug, but rather a poorly implemented feature.
     
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  6. Ticobird

    Ticobird Lovin the Tesla Life

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    People need to learn how to drive a Tesla if they intend to use the driving assist features like TACC and Autopilot. Reading the Owner's Manual would be a great place to start.
     
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  7. Dr. J

    Dr. J Member

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    True, but starting TACC from Hold? That's not a necessary feature and clearly has dangers when somebody forgets they're already in Drive. I'm struggling to figure out why Tesla implemented that. Can't come up with a good reason. Maybe related to FSD someday?
     
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  8. Tam

    Tam Well-Known Member

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    I have no problem with that as it's a convenience for me from a brake hold directly to TACC: No need to press any pedal, not the brake pedal, not the accelerator pedal! It just goes and I can brake anytime I want!
     
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  9. Ticobird

    Ticobird Lovin the Tesla Life

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    I agree. When the Brake Hold ((H)) symbol is displayed the vehicle is either already in Drive or Reverse and if the vehicle is in Reverse then I believe the TACC setting would have been erased and the vehicle will enter Drive when the right stalk is pressed downward - exactly as expected.
     
  10. Dr. J

    Dr. J Member

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    My point being that making TACC inoperable from a Hold state would require very little of you who like the instant TACC feature while eliminating a class of idiots (possible like moi) who forget what gear they're in and are startled by putting it into "Drive" (really starting TACC). It makes sense from a corporate liability/safety perspective.
     
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  11. Ticobird

    Ticobird Lovin the Tesla Life

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    #71 Ticobird, Jun 30, 2019
    Last edited: Jun 30, 2019
    I see your point. I share your opinion there is very little to be gained by Tesla allowing the TACC feature to still be active at 0 mph with the Brake Hold feature active simultaneously and Tesla would be well served to explore creating the necessary programming to eliminate it. The effect of eliminating the current feature behavior would be to just resume Drive mode after pressing down on the right stalk rather than trying to resume a TACC set speed.
     
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  12. Tam

    Tam Well-Known Member

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    I read the manual says very clearly on page 67:

    "To use Traffic-Aware Cruise Control, you must be driving at least 18 mph (30 km/h), unless a vehicle is detected ahead of you. If a vehicle is detected ahead of you, you can use TrafficAware Cruise Control at any speed, even when stationary, provided Model 3 is at least 5 feet (150 cm) behind the detected vehicle."

    1) 18MPH is not the only criteria for TACC but also:

    2) At "any speed, even when stationary, provided Model 3 is at least 5 feet (150 cm) behind the detected vehicle."

    Most people know about 18MPH

    But there are still people who do not know about "at any speed" including standing still, brake hold... if there's a vehicle in front. So, when they experience #2), they think it is a defect!

    I think it is a convenience feature because 18MPH alone is too restrictive to activate TACC / Autopilot if there's a car in front in a stop-and-go traffic scenario.
     
  13. Dr. J

    Dr. J Member

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    Does TACC deactivate if the car comes to a stop? If not (that is, if TACC stays active while the car is stopped), then a reasonable implementation would be to require the car to be in motion when TACC is first activated. That would make it more idiot-resistant, though not idiot-proof. I might still forget I previously activated TACC, but at least when I activated it, it was on purpose.
     
  14. Tam

    Tam Well-Known Member

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    Once on, TACC is deactivated when it senses

    1) a manual brake or
    2) a manual turn off by the stalk.

    So, an active TACC is not deactivated just because of stop-and-go traffic (even in full stop) if it does not sense any manual interventions above.

    Once deactivated due to manual interventions above, TACC will wait for eligible conditions to invite drivers to activate it. The eligible conditions are the 2 mentioned on post 72 quoted the manual.

    If either of 2 conditions is not met, there's no TACC invitation which means there's no circled grey icon with the speed in the center (in those pictures above, the number was either 18MPH or 70MPH).

    If either of 2 conditions is met, there's a TACC invitation which means there's a circled grey icon with the speed in the center (in those pictures above, the number was either 18MPH or 70MPH).

    There's a difference between an invitation and active TACC: grey icon versus lit-up teal icon with the speed number in the center.

    From a parking gear, some Model 3 owners just swipe down their gear stalk so fast that the first one wouldn't work because the foot did not apply the brake pedal timely.

    So they would do another swipe and it would be successful the second time because this time, the foot did apply the brake pedal timely.

    It might become a habit so they may repeatedly swipe down the gear as many times as possible until the car shifts in gear.

    The problem is: when they swipe down the stalk to quickly, they might not notice the status of TACC on the instrument clusters and they might get panic when TACC is activated.

    It's just a matter of training. Train your eyes on the status of the instrument cluster.
     
    • Helpful x 1
  15. Oldschool496

    Oldschool496 Member

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    Totally untrue, motor power may be cut but not totally. I was a Newbie Model S owner and my car was in for service, I misapplied pressure to both pedals at a very high rate of speed coming off the highway in a Signature Model S loaner I was pushing pretty hard the envelope of performance, "the brakes"(to this day I would swear those cars the pedals are closer together, I never checked) I doubt it though.

    While I was able to get it under control turning with traffic at 40-50 mph, tones going off, I had never heard to that point, it wanted to still accelerate as well.

    AS is known though the brakes always win the fight. Now I would have been better off just lifting and letting the regen do the work then reapply the brakes. At those few seconds though your accelerating into a turn pretty hard and theres a lot happening.

    I had no time reposition my foot to brake only. It happens, on occasion brief tone warning. I'm 6'3" with a 13 shoe, you gotta be real sure where your feet are with shoes that big in a model S.

    The Sig also had those flat first gen. seats you kinda can squirm around in, so my position of seating my not have been great either and getting worse as I flew around the corner.
     
    • Informative x 1
  16. SucreTease

    SucreTease Teslarian

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    This is what @wk057 has written:
     
  17. jebinc

    jebinc M3 LR AWD w/FSD and white premium interior

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    Add me to the list. M3D+ w/FSD. Happened when slowing down and it was raining. I also think I pushed the right stalk up (thinking it was the wipers) a few seconds prior. Running 2019.20.4.2.
     
    • Informative x 1
  18. MrABRanch

    MrABRanch Member

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    Yeah I think it's too easy to make this mistake, mocking people for not reading the manual, is just a poor man's tactic, clearly this stalk can be easily accidentally put into TACC and create unexpected situations.
     
  19. Ticobird

    Ticobird Lovin the Tesla Life

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    #79 Ticobird, Jul 3, 2019
    Last edited: Jul 3, 2019
    I'm running 2019.20.4.2. I tested out the described deficiency in the TACC programming and my Model 3 very gently began to accelerate, I repeat very gently began to accelerate, giving me plenty of time to realize what was happening. Oh yeah also I like to keep the following distance at 7 which helps with reacting to driver induced anomalous situations such as this. By the way, the TACC resume acceleration was so gentle that it was a bit aggravating waiting for it to reach the target speed. Additionally I perceived the TACC resume to set speed acceleration was in no way tied to a higher set speed as some might have thought was implied.
     
  20. paolodapaesan

    paolodapaesan Member

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    Couldn't believe it happened to me. Today, I'm pulling in to a straight in parking spot adjacent to 2 vehicles, right next to a speed bump in the parking lot, that was a bit awkward getting over. foot lightly on brake, iunexpected sudden acceleration directly into a retaining wall 4 ft in front of the parking spot and in a slight ditch. WTAF TESLA?
     
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