M-A-B-MCMLXXX
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Also there is emperical evidence that a long press does something different, namely that it applies the brake a second time and at a higher voltage.
It's also significantly louder when it engages.
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Also there is emperical evidence that a long press does something different, namely that it applies the brake a second time and at a higher voltage.
Just did a quick test in my garage shifting from D to Park with a short press vs long press. There was no difference in the whirring sound as the brake engaged that I could detect in volume, pitch, or duration. There WAS however, a noticeable "click" "click" at the end of the engagement when doing the long-press, suggesting that something is indeed different. I don't know what that click indicates, but it was there with the long press and not there with the short press.
My guess (and this is 100% a guess), is the clicks would be the brake "releasing" from its tighter hold once it realizes your car isn't moving and emergency braking force is not needed any longer.
It's not just unlikely, it has been disproven. There is no parking pawl.Thanks for all that replied!
I'm going along with the long press applies more pressure. My experience is that the service brake pedal goes down a little further when there has been a long press. I even thought of the possibility that there was something akin to a parking pawl in the reduction gearbox but now I believe that is unlikely.
Federal law requires a parking brake in cars (can you point to a single example of a car that meets FMVSS that does not have a parking brake?). The function is to prevent a car from rolling when parked. Dual circuit braking is irrelevant to this.The only thing is I am not sure of is why there would be a need for a more or less pressure setting. I'd think on or off would suffice. Are there two options having to do with emergency braking? I would have thought that since dual circuit braking that the concept of "emergency brake" would have died.
49 CFR § 571.135 - Standard No. 135; Light vehicle brake systems.S7.12.3. Performance requirement. The parking brake system shall hold the vehicle stationary for 5 minutes in both a forward and reverse direction on the grade.
Theoretically I supposed Tesla may be able to combine the two so that the short press also lights up that indicator, but not sure if this conflicts with other standards (like "P" mode).(4) If a separate indicator is provided for application of the parking brake as specified for S5.5.1(c), the single word “Park” or the words “Parking Brake” may be used.
The clicking sound is the same as can be heard with a power drill that's stalled. It will click as the tolerances in the drive gears and motor mounting and chuck are tightened up with torque, and click as you let go of the trigger. It's the same thing with the Tesla parking brake. The car applies power to the parking brake motor, which is a DC motor, and stops when a certain amount of current is being drawn. There's a certain cutoff on current allowed to the parking brake motors before the car stops powering them.Just did a quick test in my garage shifting from D to Park with a short press vs long press. There was no difference in the whirring sound as the brake engaged that I could detect in volume, pitch, or duration. There WAS however, a noticeable "click" "click" at the end of the engagement when doing the long-press, suggesting that something is indeed different. I don't know what that click indicates, but it was there with the long press and not there with the short press.
My guess (and this is 100% a guess), is the clicks would be the brake "releasing" from its tighter hold once it realizes your car isn't moving and emergency braking force is not needed any longer. Yes, I'm in the camp that believes the parking brake is the parking brake is the parking brake, and that holding it down simply puts it into emergency brake mode, but I fully accept this is only from my own observations and I could totally be wrong. I'm pretty sure Tesla would clearly state in the owner's manual to HOLD DOWN the park button when parking on hills if this were indeed the correct way to do it. But since we don't have any hard evidence, do what you feel is right.
Regarding door locks, no it does not have a physical door lock (most cars don't). You have an electrically activated latch that unlatches the door, if the car is "locked" then the computer ignores that the handle outside is being pulled and doesn't open the door. In a typical car, you have a manually activated latch, and the "lock" just disconnects the outside handle from the latch so nothing happens when you pull on the handle. Basically the same thing, just electric vs. manual. Cars don't have a true "lock" like the deadbolt on your front door.
"Federal law requires a parking brake in cars (can you point to a single example of a car that meets FMVSS that does not have a parking brake?). The function is to prevent a car from rolling when parked. Dual circuit braking is irrelevant to this."It's not just unlikely, it has been disproven. There is no parking pawl.
Tearing Down Tesla Segment 6: The cost of a parking pawl - Munro & Associates, Inc.
Federal law requires a parking brake in cars (can you point to a single example of a car that meets FMVSS that does not have a parking brake?). The function is to prevent a car from rolling when parked. Dual circuit braking is irrelevant to this.
49 CFR § 571.135 - Standard No. 135; Light vehicle brake systems.
The second "parking brake" mode is likely there to meet those standards. The regular mode is more akin to putting the car into "P" in a regular car, and that does not meet the standard (a parking pawl. which is what is activated in most cars when in P, is not a reliable means to prevent a car from rolling, as warned by most manufacturers). Even though in a Tesla, both modes activate the same calipers, the second mode is more explicitly clear and also meets the standards as described in the link above about having a "parking brake" indicator.
Theoretically I supposed Tesla may be able to combine the two so that the short press also lights up that indicator, but not sure if this conflicts with other standards (like "P" mode).
Long press is the parking brakeI don't know if there is a definitive answer for this. A short press indicates that you are in park. A long press adds a red "P" icon to the screen. What is the difference?
I understand that one or the other or both may use a common parking brake setup on the rear wheels. ICE powered cars use a pawl in the transmission and optionally a separate parking brake. Mechanically or electrically activated. Manual transmissions of course are treated differently.
My concern is this. In the past I would always use the parking brake on my driveway. It is a little steep. Not sure that I needed to do this but why not. Keep it exercised. The only exception would be is if it was rainy or otherwise wet and then forecast to get very cold. In the past I have had my parking brake freeze solid and would take some coaxing to get it free. I want to avoid this.
Anything "by wire" is imaginary. Drive by wire? Imaginary. Brake by wire? Imaginary. Door locks by wire? Imaginary. Parking brake by wire? Imaginary.Correct. The door locks only exist in the car’s imagination.
That feature's been there well before the Model Y came out. There's just always been some debate as to what the purpose of the long press is.Interesting to see that the low pressure "park" function was added more recently.
Perhaps they were concerned about excessive wear and decided to make the default action be at reduced pressure. This wouldn't be a wise change to secretly push out since a news story about OTA updates making people's cars roll down steep hills would be bad. But they could certainly configure it such that older cars continue with full pressure regardless of mode while newer cars default to a lighter pressure.
Or maybe it was the other way around? Maybe cars were rolling? Maybe trailer testing with the Model Y showed the need for firmer brakes so they just added a new super parking brake mode to all cars?