Makitso

When I go out to the garage and open the car door, the parking brake motor runs for a few seconds. I have reached under the car and checked the cable tension before and after it runs and it stays tight. It doesn't do this everytime I open the door, but usually the first opening of the day.
Is this normal behavior? Does anyone else experience this?
2019 Z51 A8

vbdenny

defaria

This has nothing to do with the parking brake. What you are hearing is the lock on the gas door toggling. When you are at a gas station and you open your door to fill up the gas door "unlocks". A simply tap of the gas door will open it.

If you close your door and fiddle with the pump without thinking about open the gas door you'll notice that over a short amount of time, the gas door will re-lock and you can't open it. You can open your driver door again, you'll hear that sound, and you'll be able open the gas door.

Or, just lightly touch the pad to open the driver's door without squeezing it and you'll also hear the sound and be able to open the gas door.

Of course this will only work if you have the FOB. IOW no stranger can go up to your car, squeeze or lightly touch the pad and then open your gas door to siphon gas.

Maxpowers

Are you sure it's the parking brake and not the fuel pump. My fuel pump primes every time i open the door. Like a lot of cars.

Edit. Defaria mentioned another good point RE Fuel Door actuator

Makitso

I am certain it is the parking brake, not the fuel door lock. I just made another video of the park brake apply and release function
with the ignition on engine off. It is the same sound. Listen to the first video with the volume turned up and then listen to this
video, it is the same sound. It didn't make the sound this time when I opened the door, it is random and usually does once when
first opened for the day.

owc6

The parking brake and the fuel door lock sound nothing alike.

The parking brake is a shwish/eweeeeee noise, and the fuel door is a hard hit noise; whack/knock noise.

TEXHAWK0

I think the answer to your question is that the parking brake should never be running unless you push the button to apply or release it. If I remember right, even when hill assist is on I never actually hear the brake being applied and released

TyBoo

It sure sounds like the park brake actuator to me. I have no idea why it would run with the door latch.

defaria

It was not apparent in the first video that you posted. I don't recall hearing anything like that or rather I hear that parking break noise only when I apply the eBrake usually while I'm sitting in my car and had just turned the engine off, but never from outside the car when opening the driver door. I'll have to listen today. And since the eBrake turns itself off when you start moving the car I rarely disengage it.

I assume the noise I hear when I engage the eBrake by pulling up on the eBrake lever while sitting in the car is the brake applying itself. Why would the brake apply when you're standing outside the car? When you parked your car you've engaged the eBrake right? When you come back to your drivers door afterwards and open the door, get in - is the eBrake on or off?

Also do you have an automatic or a manual? That might make a difference.

I wish the eBrake would apply itself at the same time that the exit function happens where you open your door to get out and the seat goes to the exit position. I see no reason why that doesn't happen as it would be very convenient and it would insure that you've set your eBrake in case you forget. Also considering that if you don't set your eBrake in an M7 when you get out of your car, when you return the seats will not go to their pre-configured settings, auto setting of the eBrake would be great.

Makitso

The car is a 2019 Z51 A8.
Out of habit, I always apply the parking brake after I put the car in park and before I shut
the engine off.
Out of curiosity, yesterday before I opened the car, I checked the parking brake cable and
it was tight, indicating the parking brake was applied, after opening the door I could hear the
park brake motor run, I checked the cable again and it was still tight. That is what you can
hear in the first video if you turn the volume up.So what was the park brake motor doing if the
pb was already applied? It didn't release the pb, maybe it re tensioned it.
So I looked in the owner's manual this morning and found this :

[QUOTE]The vehicle may automatically apply
the EPB in some situations when the vehicle is not moving. This is
normal, and is done to periodically check the correct operation of the EPB system.

Apparently this is normal behavior and I should just ignore it and Drive the car.
Also RTFM!

Bill Dearborn

HSA doesn't use the parking brake. It is a feature of the ABS system that uses some sensor inputs and determines how much brake pressure to apply to hold the car on a grade for up to two seconds.

Bill

gbranham

Say what?

Avanti

It makes so many wonky noises when I open the door I don't pay attention to any of 'em.