New Radio - steering wheel controls
 

Just bought a new radio from one of those local instal shops. The system has a IPOD hookup and i paid for the module that integrates the steering wheel controls (OEM Steering Wheel Interface). Anyway - the control works fine - with one exception - the left side up and down buttons only controls when going up (on the Ipod).when you push the down button it changes the to the mode features (takes you out of the ipod selection screen - and into the mode selection screen). Now I can / will take it back to the Bozo's who installed it. But i was hoping somone could explain to me how does the control module work?

Is is a closed box that once you hook it up to the proper car it atomatically works - and cannot be adjusted?

or Can it be electronically programed and is it just a bad program job?

or is it mechanically programed - like with din switches - like an old school garage door opener?

Is it something else?

Just want to know something about it when i call them on it...if i can fix, rather not take it back -if it is a quick fix. either way i want to sound like i know something about it.