P mode vs Park mode

[Mario Veras]

What’s the difference between putting the Model 3 in P versus Park mode? I’ve seen some YouTubers talk about that it makes no difference, so why is there a logo displayed on the screen if it makes no difference?
I can’t seem to find this in the manual.

 

[Tam]

What’s the difference between putting the Model 3 in P versus Park mode? I’ve seen some YouTubers talk about that it makes no difference, so why is there a logo displayed on the screen if it makes no difference?
I can’t seem to find this in the manual.

The P alone in PRND is without the parking brakes

The P with additional circled P Park with () icon means the parking brakes are activated.

 

[Mario Veras]

That’s exactly what I thought. But many disagree saying that the brake pads are pushing against the caliper in either mode.

 

[Tam]

That’s exactly what I thought. But many disagree saying that the brake pads are pushing against the caliper in either mode.

Might be the case where both parking brakes and drivers' brakes are the same.

The parking brakes from s/x are separate, not the same.

The 2 functions are not the same even when the brakes are the same: in you 3/Y, you can push and hold the parking button and you can hear the function of the parking brakes activated.

 

[KalJoMoS]

To my knowledge the difference is in that one is emergency brake that user can apply in scenarios if normal braking can’t hold the car. More of this here

 

[DerbyDave]

To my knowledge the difference is in that one is emergency brake that user can apply in scenarios if normal braking can’t hold the car. More of this here

I have a different understanding of Parking Brake from the materials Tesla provides. Pressing on the stalk while the car is moving or in Park applies the Emergency Brake. The emergency brake symbol in the dash illuminates when there is a problem, including manual use of the emergency brake while driving. In this case the driver is indicating a problem by pressing and holding the Parking button to set the Emergency Brake.
"If the instrument panel displays this
red brake indicator at any time other
than briefly when you first start
Model S, a brake system fault is
detected, or the level of the brake
fluid is low. Contact Tesla
immediately. Apply steady pressure
and keep the brakes firm to bring the
vehicle to a stop when safe to do so."

There is no park gear in the Tesla that is set by pressing and holding the Park button. There is no difference when in Park to the Tesla standing on a hill, etc., the parking brake is applied, and that is all that the Tesla does whether pressing and holding the Park button or just putting the car in Park.

 

[Mario Veras]

I have a different understanding of Parking Brake from the materials Tesla provides. Pressing on the stalk while the car is moving or in Park applies the Emergency Brake. The emergency brake symbol in the dash illuminates when there is a problem, including manual use of the emergency brake while driving. In this case the driver is indicating a problem by pressing and holding the Parking button to set the Emergency Brake.
"If the instrument panel displays this
red brake indicator at any time other
than briefly when you first start
Model S, a brake system fault is
detected, or the level of the brake
fluid is low. Contact Tesla
immediately. Apply steady pressure
and keep the brakes firm to bring the
vehicle to a stop when safe to do so."

There is no park gear in the Tesla that is set by pressing and holding the Park button. There is no difference when in Park to the Tesla standing on a hill, etc., the parking brake is applied, and that is all that the Tesla does whether pressing and holding the Park button or just putting the car in Park.

And that’s precisely where I ask the question: if there’s no difference between pressing or holding Park, then why is there a difference on what the screen displays? Press once, the car shows it’s in P. Press and hold, and then a Park logo is displayed. So there has to be a difference between the two, otherwise Tesla is just wasting their money and resources in creating two computerized functions that accomplish the same exact thing on the calipers. I believe there must be a difference.

I read somewhere that the difference is in the way the pads squeeze the calipers: Press P and the brake fluids activate the brake pads. Press and hold P and there is another mechanism that pushes the pads against the calipers which will function even if there’s no brake fluid. So basically, two different systems applying the same brakes since the car has no “park gear”. However, my understanding is that both methods press on all 4 calipers, not just on rear or front.

 

[DerbyDave]

The difference is that the driver has activated the Emergency Brake while driving feature, as the quote in my post above describes. The car is in Park, and the parking brake is engaged -- that is all. If you were driving and long-hold the Park button in, this also applies the parking brake to stop in the Emergency situation the driver has instigated by pressing and holding the Park button. I want to see Tesala material that anything else is different while parked. The symbol on the dash is illuminated after a long-press whether the car is moving or not.

While driving at speed, there is no parking gear that is set when long-pressing the Park button.

 

[DownshiftDre]

I can definitely feel and hear a difference in engagemen between “P mode” and “PARK Mode”.

Just pushing P after a drive or opening a door while in D engages a some kind of system. Thats the normal cool “whirrr” sound that one hears at the end of every drive as some actuator engages somewhere.

The 1-2 second holding of the P button to get the “PARK” symbol to illuminate is more like a parking brake hand pull. You hear a more clunky mechanical mechanism and I think you can feel/see the actual brake pedal go down some also. This one is definitely a standard rear caliper emergency brake operated independently of hydraulic fluid.

 

[DerbyDave]

It is likely that putting the car in Park or a long press of the Park button sets the rear mechanical (non-hydraulic) brakes electronically.

 

[mtmra70]

This may vary by vehicle.

On my 2023 M3P, when I put it in "Park" the manual "parking brake" button in the options notes that it is already engaged.

If I have the car in N or D, then you manually engage the parking brake, the (P) icon lights up.

In all cases, the sound on my vehicle is identical and the control button in the options reflects the parking brake is applied. I do not believe there is a difference.

 

[Mario Veras]

This may vary by vehicle.

On my 2023 M3P, when I put it in "Park" the manual "parking brake" button in the options notes that it is already engaged.

If I have the car in N or D, then you manually engage the parking brake, the (P) icon lights up.

In all cases, the sound on my vehicle is identical and the control button in the options reflects the parking brake is applied. I do not believe there is a

I’m sure it varies by vehicle. In my 2021 M3 there’s definitely a difference in the sound it makes when the park or emergency brakes engage.

 

[Msjulie]

Maybe a change past 2018 (though seems doubtful)

I swapped out the brakes (rotors) on my car and you can see the 'emergency/parking/ electric motor on each rear caliper; this thing, if you don't know how to disengage in service mode, locks the brake pads to the rotors and they'll never be off. It does so by spinning a gear to squeeze the piston up against the rotor

Seeing that, I'm hard pressed to understand parking vs Park brake unless it's a difference in force applied from the motor.

I hear these motors spin each and every time the car is taken out of D or R and not put into N; it also happens if the car is in D or R and the door opens and the driver's butt lifts ever so slightly off the seat

From all experience, on my car anyway, Park == park == emergency brake (old school lingo)

 

[android04]

Park and Parking Brake use the exact same mechanism, which is an electric motor that squeezes the rear brake pads together on the brake rotor to keep it from spinning. The only difference between them is driven by software. There are two different schools of thought as to what (if any) the physical difference could be and I will list them here. I have a way to test this, but haven't had a chance to yet.

Theory 1: The difference is that a higher voltage is applied to the Electronic Parking Brake motor (henceforth referred to as the EPB) when you press and hold the Park button and the "(P)" symbol is displayed on the screen, thus squeezing the rear brake pads a little harder and possibly being able to hold the car better against movement.

Theory 2: There is no actual physical difference and pressing and holding the Park button just forces the car to try to apply the EPB motors again as a double check feature. Then it displays the "(P)" symbol as a sign of confidence.

Either can be true. The sound we hear when pressing and holding the Park button does not mean that the EPB motors are being driven any tighter or harder, as a stalled motor will also make a sound (try it on small drill while holding the chuck and pressing the trigger). Also, pressing the brake pads harder will not keep the car from rolling any better on a steep or icy hill because it is still being limited by the traction of the two rear tires. The only way to make it better would be to also have EPB on the front wheels.

As so some Tesla vehicles being different, all Model 3/Y and all newer Model S/X use the same EPB braking mechanism that acts on the rear parking brakes. The older Model S/X had the EPB separate from the brake calipers, but the EPB still had two small brake pads that squeezed the rear brake rotors.

 

[gearchruncher]

This was discussed in depth here:

How to turn off the parking brake on a M3?

I plan on taking my M3 Performance to the track for some HPDE. I know that the brakes get really hot on the track and applying parking brakes for more than just a few minutes can cause serious damage. I can’t find anything in the owners manual or in the “Track mode” settings that allow me to...

teslamotorsclub.com

Tesla has both modes because the law requires a manual parking brake. The P icon reflects the standard that is legally required when you manually do it (which can happen while driving), but there is zero functionality difference when in "Park."

 

[launchd]

I've researched this quite a bit but more importantly, I have worked extensively on cars my whole life. Tesla uses electronic braking systems (no surprise) but they aren't unique to Tesla, so this isn't some kind of mystery.

The electronic parking brake uses the EPB controller to engage the electronic parking brake piston which clamps the rear brakes, applies a specified amount of force (more than Park), measures the current and kills the motor(s) (to prevent damage).

Putting a Tesla in park engages the Bosch brake booster (iBooster) and master cylinder assembly which in turn engages the hydraulic brake piston that forces the rear calipers to clamp down. This is also how the brake pedal works. The amount of force for Park is pre-determined/programed, same as the electronic parking break.

So, the two modes (park and the emergency parking break) are operating on independent systems (though both pistons are combined in one caliper system to reduce unsprung weight and both are causing the calipers to clamp) which is why they sound different when engaged. More importantly, if one fails, the other can still be used.

 

[launchd]

For reference, here is an aftermarket EPB controller I just found and here is a video describing Tesla's (Bosch's) brake booster

 

[DownshiftDre]

The electronic parking brake uses the EPB controller to engage the electronic parking brake piston which clamps the rear brakes, applies a specified amount of force (more than Park), measures the current and kills the motor(s) (to prevent damage).

Putting a Tesla in park engages the Bosch brake booster (iBooster) and master cylinder assembly which in turn engages the hydraulic brake piston that forces the rear calipers to clamp down. This is also how the brake pedal works. The amount of force for Park is pre-determined/programed, same as the electronic parking break.

So, the two modes (park and the emergency parking break) are operating on independent systems (though both pistons are combined in one caliper system to reduce unsprung weight and both are causing the calipers to clamp) which is why they sound different when engaged. More importantly, if one fails, the other can still be used.

Thank you. This sounds like the true answer based on the differences I hear and the approach a vehicle would need for an an independent system. Park (pushing P once) and the Parking Brake (holding P) are definitely not the same.

 

[mtmra70]

I've researched this quite a bit but more importantly, I have worked extensively on cars my whole life. Tesla uses electronic braking systems (no surprise) but they aren't unique to Tesla, so this isn't some kind of mystery.

The electronic parking brake uses the EPB controller to engage the electronic parking brake piston which clamps the rear brakes, applies a specified amount of force (more than Park), measures the current and kills the motor(s) (to prevent damage).

Putting a Tesla in park engages the Bosch brake booster (iBooster) and master cylinder assembly which in turn engages the hydraulic brake piston that forces the rear calipers to clamp down. This is also how the brake pedal works. The amount of force for Park is pre-determined/programed, same as the electronic parking break.

So, the two modes (park and the emergency parking break) are operating on independent systems (though both pistons are combined in one caliper system to reduce unsprung weight and both are causing the calipers to clamp) which is why they sound different when engaged. More importantly, if one fails, the other can still be used.

But they don't sound different in a 2023 M3P. Just tested in the garage a bit ago. Both sound identical as well as feel the same to the foot on the brake.

 

[launchd]

But they don't sound different in a 2023 M3P. Just tested in the garage a bit ago. Both sound identical as well as feel the same to the foot on the brake.

They are two different systems and must be for safety reasons. If standard braking fails, you must have a second method available to you for engagement of the brakes.

Edit: Perhaps Tesla is using the electronic emergency braking system for both Park and the emergency brake? I don’t see why they would do this though.