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      08-03-2019, 11:16 AM   #1
Enlisted Member
United Kingdom

Drives: F11 535d Touring 2014
Join Date: May 2019
Location: West Yorkshire

iTrader: (0)

Integral Active Steering (IAS) - Only seeing 1 degree movement, is my system faulty?

My 2014 F11 has IAS. However I have to say that in the 3 months I have had the car I have never been aware of it. My previous car was a 2010 F11 and I can't say I have noticed any difference between them so far as low speed steering is concerned.

Out of idle curiosity today I tried to see by how much the rear wheels counter turn when manoeuvring slowly. I parked the car with full lock, got out and had a look. I could not perceive any angle to the rear wheel, whereas I expected a small amount of counter lock (as I had been driving slowly when turning the steering wheel).

I then stood outside the stationary car and turned the steering wheel full lock the other way whilst looking at the rear wheel. I did not see any movement of it at all. I did this several times and never saw the slightest movement of the rear wheel.

I then placed a large protractor like object up against the tyre whilst at full lock. Then I turned full lock the other way and lo and behold I saw a small gap appear of about 2mm. So 2mm at that point on the tyre is the full range of movement. The point on the tyre that I was measuring is at 11cm from the centre so is on a circle of pi x 11 x 2 = 69cm circumference. A movement of 2mm represents about 1 degree around the vertical axis of rotation.

From what I have read the rear wheel should turn by up to 3 degrees in each direction so I should have observed a change of 6 degrees or 12mm, or 6x what I actually observed.

Is this to be expected in this scenario or does it seem the system is under performing? It is hard to believe that a rotation of 1 degree is going to make a significant difference and so if this is normal it begs the question as to how worthwhile this expensive option is. There are no warning lights on the dashboard.

2014 F11 535 Touring