BMW i3 Auto release parking Brake Issue

[DangerMouse]

My BMW i3 has an issue with the Auto-release parking brake and it's happening when not all of the criteria laid out in the manual are met.

The auto-release should not work if the seatbelt is not fastened (Unclipped) but mine does.
My wife had an accident as a result of this and I wanted to know if any other i3's have the same programming.

Here's how it works:
1. The car has driven with the seatbelt fastened and has come to a stop
2. The car is still in drive ready mode with drive position engaged
3. The parking brake has been manually engaged after stopping

Now if you unclip the seatbelt first and then try pressing the accelerator does the car move forward or does the parking brake stop it moving? Mine moves forward.

The manual says:

The parking brake is automatically released by operating the accelerator pedal if the following conditions are met:

1. Drive-ready state switched on.
2. Drive position engaged.
3. Driver's seat belt fastened and door closed.

Let me know if yours does this too please?

 

[eNate]

My '21 behaves similarly to yours.

If the seatbelt hasn't been buckled, the brake pedal is required to be depressed for the parking brake to be released while in D.

With the seatbelt buckled, pressing the accelerator pedal when in D automatically releases the parking brake

Once buckled the first time, the seatbelt can then be unbuckled and the parking brake can continue to be automatically released by pressing the accelerator pedal while in D mode.

Whether this is a 'bug" or intended, I think the broader point is what should a driver expect to happen if the accelerator pedal is depressed while the car in engaged in D mode? Or asked a different way, why would a driver step on the accelerator pedal to do anything other than "go?"

Sorry to be preachy, but nanny devices can only get us so far and often get in the way. If we're being honest (and we should be), did your wife really expect the car not to move? It's easy to blame this on the tech, but really, shouldn't the driver be held to account for pressing Go while the car is in gear?

 

[mojo]

Mine is exactly the same as eNate's - the behaviour depends on whether the seatbelt has been fastened since "drive ready" state was engaged. So the wording as stated in the manual is correct - you are referring to a condition beyond the manual's item 3. - where the belt was fastened but was subsequently unfastened.

I suspect that this programming is deliberate, to cater for people like myself, who have to lean out of the driver's window or make other similar contortions while parking their car - you can't easily do that with the seatbelt fastened.

 

[eNate]

I suspect that this programming is deliberate, to cater for people like myself, who have to lean out of the driver's window or make other similar contortions while parking their car - you can't easily do that with the seatbelt fastened.

The other car in our household has a seatbelt nanny that will activate the hydraulic brakes with gusto if the car is being driven in reverse, the seatbelt is not buckled, and the driver's seat occupancy sensor is relieved. So if "contorted" while backing up, and there's just the slightest amount of butt lift, BAM! the car stops with such violence you'd think you'd hit a fire hydrant. Rather annoying.

 

[DangerMouse]

Thanks for checking this for me as I had no way to check if it was a factory setting or just mine.

eNate, I do hear what you are saying about the accelerator's expected behaviour but I would counter that with a manually operated handbrake's expected behaviour being to stop the wheels from moving in all cases such as on a hill to stop it rolling etc.

Considering the combination of manually putting the handbrake on and then un-doing the seatbelt you would think that constitutes an intention to NOT drive.

Regarding the manual I read it as any time the seatbelt is unhooked or the door is open it should not auto-release the parking brake for safety reasons. Its very unclear if this simple rule only applies in certain scenarios (i.e. depending on what you were doing just before). Still not convinced this is intentional by BMW.

 

[eNate]

With the i3, when P is engaged, a motorized pawl is driven into a gear wheel in the transmission, physically l locking the entire drivetrain immobile.

Other EVs – I'm thinking specifically of the VW ID.4 – eliminate the parking pawl and rely only on the parking brake. Some owners have reported their ID.4s have rolled when parked on inclines.

But I'm just throwing this out there: the "by the book" method to immobilize the i3 is P. I hear you on the expected outcome of activating the parking brake, but that's at odds with the expected outcome of pressing the accelerator + D mode engaged.

I do hope your wife and the car are ok, and I'm curious to hear what BMW has to say if you bring this to their attention. If you get a response, please report back?

 

[EvanstonI3]

1. The car has driven with the seatbelt fastened and has come to a stop
2. The car is still in drive ready mode with drive position engaged
3. The parking brake has been manually engaged after stopping

Now if you unclip the seatbelt first and then try pressing the accelerator does the car move forward or does the parking brake stop it moving? Mine moves forward.

My 2017 does exactly the same thing.

It sounds to me as if you are trying to find a way to blame BMW for the accident by assuming the electrically engaged parking brake should work the same way as an old manually engaged parking brake.

 

[DangerMouse]

I just wanted to know if it’s a standard behaviour but yes some blame should be with BMW as it’s not only unexpected behaviour in my scenario but also it’s illegal to drive without your seatbelt on so why would you make it that way.

 

[mojo]

it’s illegal to drive without your seatbelt on

Obviously, laws vary depending on where you are, but that's not true in the UK. There are exemptions, and one of those is for a driver who is reversing:

https://www.gov.uk/seat-belts-law/when-you-dont-need-to-wear-a-seat-belt

And I'm afraid it's not correct to assume that if you put the parking brake on and take your seatbelt off you are NOT about to drive. I do it every time I park my car in the garage, as my driveway is on a steep slope.

 

[DangerMouse]

If reversing that's a very specific and different scenario. In that case the car can act accordingly when the driver puts it in reverse. I still fail to see any reason you need to drive forward, having just removed your seatbelt after applying a parking brake. If there is this scenario I would expect it to be secondary to a number of potential safety scenarios and the handbrake should be operated manually rather than automatically in those cases. Just my opinion but if it's not safe then the auto handbrake is actually negating the main reason for having a parking brake to begin with.

This is a definition I found:
A parking brake's primary function is to prevent the vehicle’s motion when it is parked. This system is technically a sub-part of the more advanced ‘Brake by Wire’ system. In addition to preventing the vehicle’s motion when parked, these brakes also play an essential role in avoiding the backward motion of vehicles that are resuming movement on a slope.

In the case when on a slope I would not expect the driver to either open the door or remove the seatbelt unless they were in fact already parked.

Good debate.

 

[EvanstonI3]

This is a definition I found:
A parking brake's primary function is to prevent the vehicle’s motion when it is parked.

Except in your case, your wife did not put the car in PARK. She left it in DRIVE mode.

 

[mojo]

I still fail to see any reason you need to drive forward, having just removed your seatbelt after applying a parking brake.

That is exactly the sequence that I use every time I park my car in the garage - I have to go forwards because I can't get out of the car if I go in backwards, and I use the parking brake because of the slope.

I can sympathise with anyone who has reservations about the way that the auto handbrake works. I have problems with the fact that it is either on or off - there is for example no way to bring the car gently to a halt from very slow speed with the electric handbrake, and the speed with which it runs away when you are reversing downhill can be a shock if you're not expecting it.

But IMO you stand no chance of getting BMW to accept any blame at all. An academic discussion in which you try to convince everyone else that BMW is partly to blame is one thing, but you should not (if that is what you're contemplating) think there is any possibility that BMW's legal advisors will make any concessions on that front.

 

[3pete]

I can confirm my 2014 behaves the same way: once the seat belt is used once, the car will release the parking brake if you hit the accelerator while in "Drive."

Out of curiosity, I even tried this sequence: Car on, belt on, belt off, shift to drive, hit accelerator, and it still released the parking brake, so the "belt on" piece doesn't even have to be while the car is in "Drive".

If I had to guess, I would say BMW thinks the most likely time for unintended-acceleration to occur is during startup, while the driver-to-be is possibly doing other things like putting away item(s) they carried into the car with them (briefcase, groceries, coffee). I would not intentionally shift to "D" until I was actually ready to drive, but it is possible to bump the shift lever into "D" while swinging a pizza box over the wheel, for instance.

Once the driver is buckled in I guess BMW thinks your focus is now adequately on driving so you're in charge until the car is turned off. I actually agree with them on this but I may be biased from my car history; the first car I had with auto-release parking brake would release it as soon as you shifted to drive, no accelerator needed. I'm 99% sure that was unrelated to seat-belt status as well so I've found BMW's approach thoughtful but not overbearing.

I still fail to see any reason you need to drive forward, having just removed your seatbelt after applying a parking brake.

Unfortunately, I think you'll find this line of reasoning will turn back around onto your situation and turn into: "I fail to see any reason someone would need to press the accelerator while in drive if they don't expect the car to move." Not trying to be antagonistic here, just suggesting that might not be a productive route to go down.

Apropos of the legality, it's actually still legal to drive without a seatbelt in New Hampshire... as long as you're over 18.

 

[eNate]

If I had to guess, I would say BMW thinks the most likely time for unintended-acceleration to occur is during startup, while the driver-to-be is possibly doing other things like putting away item(s) they carried into the car with them (briefcase, groceries, coffee). I would not intentionally shift to "D" until I was actually ready to drive, but it is possible to bump the shift lever into "D" while swinging a pizza box over the wheel, for instance.

Although to select a drive mode, the brake pedal needs to be depressed, regardless of seatbelt status. So there's a permanent built-in safety feature there.

Under normal driving, BMW did make the conscious decision to allow the parking brake to automatically release when pressing the accelerator. I'm supposing this was for driver convenience at stoplights or on hills. Certainly a nicety, not a necessity. But by doing so BMW has communicated to drivers that the parking brake is not "permanent" once the accelerator is pressed, ignoring seatbelt status for the moment.

I'm reminded of the story of Gary Hoy, who apparently liked it impress visitors of the robustness of the construction of the highrise he worked in (and of his courage) by taking a running leap into the building's windows, harmlessly bouncing off. One summer day in 1993 the window released, and he and the sheet of intact glass plunged to their demise on the streets of Toronto.