Anti - Skid service required

Hi, I have Volvo S80 2005 version, D5 auto, with a similar problem, on starting dash message says "Anti-skid temporarily off" and then shortly after, usually when when turning in either direction at or near full lock, it turns to "Anti-Skid Service required" obviously not abs, as abs light not on.

BCN fault code - 0109 - Communication between control modules. Communication with the stering angle sensor, internal fault.

However can't find problem with steering angle. And my tame mechanic says seen it on merc e-class was then told by the maindealer to change the BCM at huge cost, made no difference what so ever. So very frightened of going down that route.

seems to be to do with the steering; though I do get an occasional creaking sound when turning on full lock, any ideas! Tracking etc all checked recently and found to be ok. Gear box has been out and back in recently and fault only showed when original problem with box started. Box now fixed, just left with this fault code before I can sell it.

Please help!