Automatic braking - unexpected
04-28-2019, 04:39 PM
#1
Instructor
Thread Starter
Automatic braking - unexpected
Folks
was dricing my new P4S today in a fast tightening turn (but nowhere near the edge) and it gave me a zap of the brakes. It did it at the same location the other day. Any idea what system is causing this and why? Thanks!
was dricing my new P4S today in a fast tightening turn (but nowhere near the edge) and it gave me a zap of the brakes. It did it at the same location the other day. Any idea what system is causing this and why? Thanks!
04-29-2019, 11:49 AM
#2
Burning Brakes
What kind of nanny-type stuff do you have active at the time? Maybe the LKA is 'seeing' something, perhaps worsened by 'confusion' over lane markers or lack thereof?
04-29-2019, 12:32 PM
#3
Instructor
Thread Starter
It only has LCA, not LKA. It has PSM, so might have been some sort of early threshold stability maneuver - but as I mentioned, I was no where near a limit. The car doesn't have ACC. I had wondered if it had some sort of forward sensing system, that might have gotten confused by markers etc - but unclear what system that would be.
Or it is PSM - but does that trigger brakes during spirited but not aggressive driving? I believe the thresholds go up in Sport / Sport + modes, but it is was this, that means the base level is pretty low....
Thanks, Ed
Or it is PSM - but does that trigger brakes during spirited but not aggressive driving? I believe the thresholds go up in Sport / Sport + modes, but it is was this, that means the base level is pretty low....
Thanks, Ed
05-02-2019, 09:00 AM
#4
I would wonder if perhaps it detected something in front of a car, and assumed it was another car.
I only have a 2012 PTTS, so I don't have those features, but my RS7 had it, and it was crazy sensitive. I never had it engage on a corner, but it would often fire off when a car was turning in front of me pretty car up, and I wouldn't immediately slow down. The RS7 would think that the car stopped in the middle of the lane, rather than being 3/4 out of it making its turn. It would scare the crap out of me with a loud alarm sound and in a couple of cases nearly slam the brakes.
I didn't disable it, because it keep a few close calls (I would say it saved me but potentially could have) from giving me an adrenaline dump by activating very early if my attention was off the road in traffic. I Jeep SRT also had this feature and behaved much the same way.
I only have a 2012 PTTS, so I don't have those features, but my RS7 had it, and it was crazy sensitive. I never had it engage on a corner, but it would often fire off when a car was turning in front of me pretty car up, and I wouldn't immediately slow down. The RS7 would think that the car stopped in the middle of the lane, rather than being 3/4 out of it making its turn. It would scare the crap out of me with a loud alarm sound and in a couple of cases nearly slam the brakes.
I didn't disable it, because it keep a few close calls (I would say it saved me but potentially could have) from giving me an adrenaline dump by activating very early if my attention was off the road in traffic. I Jeep SRT also had this feature and behaved much the same way.
05-02-2019, 01:10 PM
#5
I've had LKA do funky stuff like that - had to disable it. It felt more like the system grabbing the steering wheel and turning it, but I definitely felt some brake application as well.
05-02-2019, 03:38 PM
#6
Burning Brakes
I would wonder if perhaps it detected something in front of a car, and assumed it was another car.
I only have a 2012 PTTS, so I don't have those features, but my RS7 had it, and it was crazy sensitive. I never had it engage on a corner, but it would often fire off when a car was turning in front of me pretty car up, and I wouldn't immediately slow down. The RS7 would think that the car stopped in the middle of the lane, rather than being 3/4 out of it making its turn. It would scare the crap out of me with a loud alarm sound and in a couple of cases nearly slam the brakes.
I didn't disable it, because it keep a few close calls (I would say it saved me but potentially could have) from giving me an adrenaline dump by activating very early if my attention was off the road in traffic. I Jeep SRT also had this feature and behaved much the same way.
I only have a 2012 PTTS, so I don't have those features, but my RS7 had it, and it was crazy sensitive. I never had it engage on a corner, but it would often fire off when a car was turning in front of me pretty car up, and I wouldn't immediately slow down. The RS7 would think that the car stopped in the middle of the lane, rather than being 3/4 out of it making its turn. It would scare the crap out of me with a loud alarm sound and in a couple of cases nearly slam the brakes.
I didn't disable it, because it keep a few close calls (I would say it saved me but potentially could have) from giving me an adrenaline dump by activating very early if my attention was off the road in traffic. I Jeep SRT also had this feature and behaved much the same way.
Yup that's LKA for sure. Not sure if I've had LKA also pump the brakes, or if that's a separate safety system. Either way, I don't love the feel of it grabbing the wheel and exerting force on it. Maybe I'll try it with the sound alert active but the 'grab the wheel' correction disabled.