angle sensor, speed sensor or both of them?

Wouldnt it throw a code or something? would speedo work if it was a wheel speed sensor? wouldnt the thing react to lock-to-lock steering wheel turnings if it was an angle sensor.. guys, im really confused.... and the most interesting that about all that is a dealer saying - BAD ABS Module. because it throws no codes... also he explained that the the module checks itself only at speed more than 40 km/h - then three little yellow lights come up... As Im writing this post, and Idea came up to me - maybe I should ask them to read codes/diagnose AFTER I reach that speed and lights are on.. because as far as I know dealer turned my car on, never reached that speed( max 5km/h to drive the car next to their computer )and checked the system without those lights on board.
I think should be worth of trying..
Can I have few words from your experience, guys?
P.S. We have to create something like ZEITGEIST movie on official bmw dealers =))