I need help identifying and then describing to my dealer the problem with my active steering on my 2006 530i.

In my words, it feels sticky under certain circumstances best described as - when traveling at over 80km/h and being fairly aggressive in long corners, if I need to adjust the steering the wheel is heavy and unresponsive (initially) then, in what seems seconds later, becomes light and over responsive. This is the extreme example and I notice the problem in other situations.

Other ways I have used to describe the problem is - it appears to suffer from hysteresis (engineering term http://en.wikipedia.org/wiki/Hysteresis).

I have returned the car twice to my dealer who attempts to drive around inner city streets in peak hour saying no fault found but has done wheel alignment and full geometry checks and adjustments (changed dynamics from over steer to under steer at the limit). The second attempt by the dealer was to query the tyre pressures.

I have driven other active steering e60's and do not have the same observations.

Thank you in advance.

 

I can't say for sure but could it simply be something wrong with the power steering system (as opposed to the active steering and/or alignment?)

Does the problem feel more like the power assist is fluctuating?

 

Hmmm....what would I be looking for to distinguish between active steering and power steering components?

I don't think it feels like the power assist is fluctuating.

I described it today to my mechanic as not behaving with BMW dynamics more like Mercedes steering dynamics, he lit up with "so soft and mushy and ill defined". I said yes, yes, yes.

 

I have just got my car back and the problem appears to be the active steering! The fix, reset the controller/computer for Active Steering. All good.