mbkb2017
Posts: 1
Joined: Thu Aug 17, 2017 4:16 am

Unexpected, very powerful, acceleration surge BMW i3

Thu Aug 17, 2017 4:51 am

In October 2016, my partner and I purchased a new BMW i3, without the range extender. We understand we were one of the first buyers of this updated i3 in the U.K.

Since then, in January 2017 (my partner driving) and again in April 2017 (when I was driving) we have had two accidents, both caused by a sudden unexpected, very powerful, acceleration surge.

We are interested to know whether any other i3 owners have experienced a similar event and what the outcomes were.

theothertom
Posts: 363
Joined: Mon Mar 20, 2017 6:08 am
Location: South Carolina

Re: Unexpected, very powerful, acceleration surge BMW i3

Thu Aug 17, 2017 5:43 am

I haven't heard of anything like that but all cars these days have a lot of electronics, which can be buggy. I assume you've taken it back to the dealer for analysis ?

alohart
Posts: 1537
Joined: Sat Nov 01, 2014 7:36 pm
Location: Honolulu, HI

Re: Unexpected, very powerful, acceleration surge BMW i3

Thu Aug 17, 2017 8:18 am

Isn't there an event recorder that BMW can access to learn more about the circumstances when a collision occurred?
Aloha,
Art

2014 BMW i3 Arravani Grey, Giga World, Tech + Driving Assist, Parking Assist, DC Fast Charging, JuiceBox EVSE

ASUN
Posts: 131
Joined: Mon Nov 09, 2015 10:25 am
Location: Vancouver, BC

Re: Unexpected, very powerful, acceleration surge BMW i3

Thu Aug 17, 2017 10:55 am

Were you slowing down, hit a BIG bump on the road, and the car jumps forward?

This does happen, and it is quite scary indeed.

I posted about this previously, and the responses state it's regarding the car letting go of the drivetrain to release the tension from the bump on the road.
- ASUN, 2016 BMW i3 BEV, Arravani Grey, Suite Interior, 20's, since Oct 25, 2015

nitramluap
Posts: 102
Joined: Thu Jul 14, 2016 12:43 am
Location: Not the USA

Re: Unexpected, very powerful, acceleration surge BMW i3

Fri Aug 18, 2017 3:00 am

ASUN wrote:Were you slowing down, hit a BIG bump on the road, and the car jumps forward?

This does happen, and it is quite scary indeed.

I posted about this previously, and the responses state it's regarding the car letting go of the drivetrain to release the tension from the bump on the road.


This is regenerative braking backing off when the DSC/Traction control is triggered (i.e. Bumpy or slippery surface). This is normal and it is to prevent the regenerative braking locking the rear wheels and causing loss of control (basically a handbrake turn). It can also be predicted by looking at the road surface and considering how much regeneration you're demanding.

It gives the impression of a 'surge', but it's really just the braking effect from regeneration being removed. The brain interprets this as 'accelerating' in a way.

ASUN
Posts: 131
Joined: Mon Nov 09, 2015 10:25 am
Location: Vancouver, BC

Re: Unexpected, very powerful, acceleration surge BMW i3

Fri Aug 18, 2017 9:50 am

nitramluap wrote:
ASUN wrote:Were you slowing down, hit a BIG bump on the road, and the car jumps forward?

This does happen, and it is quite scary indeed.

I posted about this previously, and the responses state it's regarding the car letting go of the drivetrain to release the tension from the bump on the road.


This is regenerative braking backing off when the DSC/Traction control is triggered (i.e. Bumpy or slippery surface). This is normal and it is to prevent the regenerative braking locking the rear wheels and causing loss of control (basically a handbrake turn). It can also be predicted by looking at the road surface and considering how much regeneration you're demanding.

It gives the impression of a 'surge', but it's really just the braking effect from regeneration being removed. The brain interprets this as 'accelerating' in a way.


Yes...as per above... ;)
- ASUN, 2016 BMW i3 BEV, Arravani Grey, Suite Interior, 20's, since Oct 25, 2015

nitramluap
Posts: 102
Joined: Thu Jul 14, 2016 12:43 am
Location: Not the USA

Re: Unexpected, very powerful, acceleration surge BMW i3

Fri Aug 18, 2017 1:33 pm

ASUN wrote:'

Yes...as per above... ;)


Yeah, with more of an explanation as to *why* exactly - for the OP, not you. If it upsets you, I can delete my post.

ASUN
Posts: 131
Joined: Mon Nov 09, 2015 10:25 am
Location: Vancouver, BC

Re: Unexpected, very powerful, acceleration surge BMW i3

Mon Aug 21, 2017 11:29 am

nitramluap wrote:
ASUN wrote:'

Yes...as per above... ;)


Yeah, with more of an explanation as to *why* exactly - for the OP, not you. If it upsets you, I can delete my post.


Please don't get me wrong. I appreciate your in-depth answer.

Was making a joke...I guess you did not see my smiley face :D
- ASUN, 2016 BMW i3 BEV, Arravani Grey, Suite Interior, 20's, since Oct 25, 2015

nitramluap
Posts: 102
Joined: Thu Jul 14, 2016 12:43 am
Location: Not the USA

Re: Unexpected, very powerful, acceleration surge BMW i3

Mon Aug 21, 2017 1:25 pm

All good... and it was a winky face, not a smiley face... slightly different meanings. ;)

ks2017
Posts: 5
Joined: Mon Aug 21, 2017 5:56 pm

Re: Unexpected, very powerful, acceleration surge BMW i3

Mon Aug 21, 2017 6:09 pm

Hi ASUN,
My wife has experienced the same trouble during to park it in to our garage on last week.
The car is 2015 Rex.
After she has stopped the vehicle in front of the porch, it showed some kind of fault message on display.
And suddenly it start to accelerate and run against the stairway in front of the porch.
The car is loaner vehicle from BMW dealer and waiting for delivery of i3...
She had a whiplash injury and hospitalized yesterday...
I am waiting for the report from dealer of BMW..
When we've got the report from them, I would like to share it.

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