Hill assist roll back

inkey$

Lifer
 Sevenoaks & Suffolk
Anybody else with hill assist notice that when on the slightest of inclines (virtually flat) that in traffic and stationery, the sensitivity of the system means that when it disengages after a couple of seconds, the action of release gives the car enough inertia to roll backwards slowly?
 
Not something I've noticed myself. On a small incline I find the system is normally sensible enough to not even engage in the first place. No problems like that on my previous Z4C or current Z4M.
 
Maybe the sensitivity can be adjusted. Not a massive issue, just something I have to get used to I guess.
 
Seems odd that you're experiencing that though - It's probably normal to be honest, but it should give you enough time to get on the accelerator anyway, shouldn't it?

May be worth asking someone near you if you could try their car for comparison. I always find that puts my mind at ease, and find it's normal.
 
Just wished it was a proper system like with the VW. I hate this couple of seconds thing, would be great if it just held until you drove away.
 
Georgio said:
What's wrong with the old fashioned way of holding the car on the clutch? :D

http://www.z4-forum.com/forum/viewtopic.php?f=3&t=30989 :D
 
Interesting read; one of my cars is a 1991 Celica that I've had for 16 years. In that time I've done 135k miles in it (mostly winter driving as I used an Elise during the summer) and I've replaced the clutch once which was 10 years ago.
So either I'm an awfully smooth driver or Toyota don't make 'em like they used to... :roll:

pvr said:
Georgio said:
What's wrong with the old fashioned way of holding the car on the clutch? :D

http://www.z4-forum.com/forum/viewtopic.php?f=3&t=30989 :D
 
Can someone explain how this is mechanically possible? All this feature does is hold pressure in the brake line for a couple seconds or until the clutch engages. I see no way for the release of brake line pressure to impart any kind of motion on the car. Maybe I'm blind.
 
I think its just physics bcworks. The very movement of the break release is enough to set the car in small amounts of motion when stationery but on unlevel surfaces. Never did it on my old roadster without hill assist.
 
inkey$ said:
I think its just physics bcworks. The very movement of the break release is enough to set the car in small amounts of motion when stationery but on unlevel surfaces. Never did it on my old roadster without hill assist.

probably because you had your foot on the brakes :poke:
 
srhutch said:
inkey$ said:
I think its just physics bcworks. The very movement of the break release is enough to set the car in small amounts of motion when stationery but on unlevel surfaces. Never did it on my old roadster without hill assist.

probably because you had your foot on the brakes :poke:

:headbang: That might have been it :D
 
there's a set of lights on a bridge near me where this is very noticeable, but I like how the car is, it's predictable..

Brakes on, clutch in, 1st selected.. release brakes & you have 2 seconds before the brakes release.. if they release & you're on a hill, expect to roll back/forward.
 
What's wrong with using the handbrake. Too many new cars have nannying electronics which are supposed to assist us when in reality they are not good enough and actually get in the way. Electronic handbrakes, automatic wipers that don't wipe when you want and do when you don't automatic lights that don't come on when you want them.These things really p*ss me off. I have them on 2 cars from different manufacturers and none of them work properly in the real world. I am quite capable of performing a hill start, ditto wiping my windscreen when I want anbd putting lights on when needed. I'd rather they spent the cash on better standard fit hi fi. :thumbsdown: :headbang:
 
i love hill assist :thumbsup: until i jump into my wifes car and forget at the first hill :(
had some near misses :!:
 
inkey$ said:
I think its just physics bcworks. The very movement of the break release is enough to set the car in small amounts of motion when stationery but on unlevel surfaces. Never did it on my old roadster without hill assist.
Of course it's physics, that's not really an explanation. You're saying the short movement of several ml of brake fluid is enough to move a 1400 kg car? More likely the "unlevel" surface itself combined with the lower rolling resistance of modern tires. I guess I could say it's just gravity. My DD without hill assist has rolled without any coaxing on the 2% slope (essentially flat except for allowance for drainage) in front of my garage.
 
That's not what I'm saying. I'm saying that the very action of the brakes releasing combined with the very very slight gradient is enough to provide creep back. I know this because it's actually happening :) On the roadster when stationery and without hill assist my brakes were never on automatically so I could stop the car and adjust with slight clutch if needed. Could do that now of course, but the auto braking doesn't need me to so my natural [and probably lazy] stationery activity is the most likely cause.

2 seconds later, brakes release and inertia/physics/gravity kicks in :)
 
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