General notes on dynamic steering — AUDI

General notes on dynamic steering
In conventional steering systems there is a direct mechanical connection between the steering wheel and the steering rack. This dictates a fixed ratio between the steering wheel lock angle and the turn angle of the steered wheels. In this design, only one steering ratio can be implemented on a vehicle at a time. Selecting the appropriate ratio always represents a compromise in meeting the different - and sometimes conflicting - requirements.
The key requirements can only be fully met by a variable steering ratio. A ratio of this kind varies the actual turn angle of the wheels depending on the vehicle speed and steering angle. The dynamic steering system basically employs two variable steering ratios, with comfort and performance-oriented characteristics respectively.
The variable ratios are achieved by means of an additional electro-mechanical drive of the steering pinion, which is superimposed on the steering input from the driver. In an emergency - that is, if this drive fails - the steering operates just like a conventional steering system. The mechanical connection between the steering wheel and the front axle is not broken.
However, there are many other advantages to dynamic steering. In interaction with the ESP and its sensors, the system is also activated when critical driving states are impending. By targeted variation of the front wheel turn angle, the dynamic steering system assists the ESP at the limits of the vehicle's handling.
The
“adjuster”
on the steering column is permanently installed. The steering column must be renewed if the
“adjuster”
is defective.
The
“valve”
on the power steering pump is permanently installed. The power steering pump must be renewed if the
“valve”
is defective.
The basic setting for the dynamic steering system must be performed correctly to ensure proper functioning.
Note
The
steering angle sender
G85
must be calibrated using the
steering wheel balance
VAS 6458
before the basic setting can be performed.
The basic setting must be performed if:
The
active steering control unit
J792
has been renewed.
The front axle toe setting has been changed.
The rear axle toe setting has been changed.
The running gear of the vehicle has been modified in any way – e.g. conversion from standard running gear to sports running gear.
The
steering angle sender
G85
has been calibrated.
The steering column has been renewed.
The steering wheel is not straight when driving in a straight line.
Note
Before performing the basic setting on the dynamic steering system, check the event memory and rectify any faults. The basic setting for the dynamic steering system must always be performed using the wheel alignment equipment approved by VW/Audi.
For more information on the dynamic steering system refer to
Self-study programme
No.
402
Audi dynamic steering
.