If your vehicle is showing steering wheel control buttons not working, here are the most likely causes and the parts you'll need to fix each one.
The clockspring is a coiled ribbon cable behind the steering wheel that maintains electrical connections while the wheel turns. When it breaks from normal wear, steering wheel buttons, the horn, and the airbag often stop working.
If an aftermarket stereo was recently installed, the necessary steering wheel control adapter module may have been omitted, wired incorrectly, or lost its programming.
The physical buttons and internal contacts can wear out, corrode, or get sticky from spilled liquids over time, causing individual buttons or entire clusters to fail.
A blown fuse can cut power to the steering wheel controls. This usually affects other interior electronics or dashboard illumination at the same time.
The BCM processes the signals from the steering wheel buttons. A software glitch or hardware failure in this module can cause it to ignore button inputs.