Turn signals/indicators stays on 118i

Hi all,
Well as the title suggest when i turn on the turn indicator even after ive completed my turn or re-center the steering wheel the turn signal stays on. The seller told me its the steering angle sensor (SAS). Could the SAS really cause this? Does anyone have any suggestions or ideas on how to fix this. The car is a 2006 118i.

Thanks everyone.

Edit: part of me thinks that if the SAS were bad you would have other faults like a DSC warning light, etc.

It may be worth while to have the DSC and instrument cluster scanned for error codes before throwing parts at it.

I do have a DSC warning light.. Well DTC to be precise accompanied with an orange park brake light..
I went to a friends shop today and he had the cheapo OBD2 scanners and it didnt pickup anything...

Generic OBD scanners will not pick up on any error codes except for those in the engine. If the DCS light is on, then the steering angle sensor is almost definitely the cause of you issue.

mr_bean,
I done the SAS cleanout on the E90 forum and now my turn signal and my dtc issue went away!! I cant remember the last time i was this happy fixing something on my car!

Thanks to all!