On my previous Activa (now Gareth's) I saw and cleared this fault several times. Each time it seemed to improve the handling, particularly making the Activa System work more sharply.
I diagnosed Gareth's and mine yesterday and we both had logged Steering Angle faults. The faults cleared. Gareth and I both noted an improvement afterward, in particular, anti-roll response.
Why? Just a theory. Does the logging of a fault (intermittent or not) on the steering angle system cause the ECU to diaregard the input from the sensor and perhaps rely mainly on input from the Yaw Sensor to determine the car is rolling and then operating the Activa Electrovalve to bring in hard roll control? If the Activa Electrovalve is released, roll correction will be soft and under control of the roll corrector but before any roll correction is applied, the "give" has to be taken up in the Activa Balancing Sphere, thus it will not feel as sharp. If the steering angle sensor is used to operate the Activa Electrovalve, it will bypass the Activa Balancing Sphere and significantly stiffen the roll bars.
In practice, it is a good idea to diagnose the Suspension ECU regularly and clear all intermittent faults. Trouble is, I believe they can only be cleared with a Lexia
