Active Handling kicks on in low speed turns
Thread Starter
8th Gear
Joined: Nov 2019
Posts: 8
Likes: 0
Active Handling kicks on in low speed turns
Hoping someone can help point me in the right direction here. I replaced the steering knuckles and tie rod ends with some aftermarket versions to increase my steering angle. Tires and wheels are stock sizing. When I do low speed (less than 10mph) with TC on, the active handling will kick in and start braking one of the front wheels. However, it doesn't do this when I'm moving at normal street or freeway speeds. At first I thought it was a wheel speed sensor but I would expect it to kick on randomly and regardless of speed if it was due to the sensor. What do you all think?
Melting Slicks
Joined: Dec 2018
Posts: 2,647
Likes: 1,381
From: Orange County, CA
Have you checked for any fault codes in the TCS system? (using the onboard diagnostics)
Also sounds to me like a wheel speed sensor. Though may be steering angle sensor?
I don't know how it is on the C5, but on Audis there is a diagnostic tool I can use to watch reported wheel speeds in real time. In the past I used this to determine the problem corner (turned out to be a broken tone ring).
Also sounds to me like a wheel speed sensor. Though may be steering angle sensor?
I don't know how it is on the C5, but on Audis there is a diagnostic tool I can use to watch reported wheel speeds in real time. In the past I used this to determine the problem corner (turned out to be a broken tone ring).
Instructor
Joined: Jul 2019
Posts: 158
Likes: 104
Is it possible that your low speed turns are much sharper than your "normal" speed turns? The sharper the turn, the more differential there is between the wheel speed on the inside and outside tires. That might be enough to trigger the active handling..
Advanced
Joined: Aug 2020
Posts: 68
Likes: 3
From: NY
I just installed Turn One steering rack with the increased steering ratio and am getting the same
issue. Slow turns in a parking lot or at a stop sign will trigger the active handling same as you. I think it has something to do with the steering wheel position and yaw rate sensor. The car is turning more than the steering thinks it turning and it think you’re out of control. I haven’t replaced the steering wheel sensor yet cause I’m dreading the job. Did you ever figure out what happened?
issue. Slow turns in a parking lot or at a stop sign will trigger the active handling same as you. I think it has something to do with the steering wheel position and yaw rate sensor. The car is turning more than the steering thinks it turning and it think you’re out of control. I haven’t replaced the steering wheel sensor yet cause I’m dreading the job. Did you ever figure out what happened?
Drifting
Joined: Nov 2017
Posts: 1,388
Likes: 301
When the measured yaw rate isn't what the system expects for your speed and steering wheel angle, it assumes you're understeering or oversteering, and the Active Handling system kicks in to correct that problem.
Both of the mods listed above cause the car to yaw faster than the system expects, for a given steering wheel angle. I mean that's the entire reason you installed them, right?
So of course the Active Handling system interprets the increased yaw rate as oversteer, so of course it tries to correct that (non-existent) oversteer.
There's a thread somewhere on the forum where somebody is working on SWPS signal processor, which (if/when it is completed) will allow you to fudge the SWPS signal to be what the AH system expects. The theory is pretty straightforward, but the SWPS signal is a little weird, so it's not a trivial project. But it seems do-able. Some searching should hopefully find the thread.
