Clock spring

More than likely to be a bad clock spring. Most of the functions are controlled through a different resistance for the function. If the resistance for change volume was say 10 ohms and say a command was higher and the wire is broken or shorted you would get the wrong input.

Not hard to replace on that vehicle. First me sure the steering wheel is centered and block the wheels so it cannot move.
Disconnect the battery negative terminal. Then wait five minutes before you start removing parts.

Next remove the two screws that hold the airbag module to the steering wheel. Pull the module out and down so you can disconnect the two wire connections on the back. Set it out of the way.

Next you remove the clip and nut in the center of the steering wheel and use a puller to remove the wheel itself from the shaft. As a precaution a couple marker dots will help ensure it goes back on in the correct place. Disconnect the wiring to the clock spring.
Next you remove the plastic cover over the steering column. The clock spring module is the next item you come to. Disconnect its wiring and the horn connection and remove the module.

To install the replacement you reverse the process -- except you need to verify that the spring is centered. To do that you install the wiring then rotate the inner tab clockwise until it stops. Now rotate it counter clockwise 2.5 turns and line up the marks on the housing. If the wheels are straight ahead the spring should slide into place with very little motion. Then just reinstall the parts and reconnect the battery when finished.
Everything should return to proper function as soon as you start the engine and the airbag test runs.