I have a Pulsar on my 21 Silverado and it lets me control the AFM, Start/Stop, adjust the speedometer for tire size, speed limiter, tire pressure sensors and probably some more things I can't remember. It plugs in under the hood and lets me control things with the steering wheel buttons. Takes about 2 minutes to install or remove.
https://www.rangetechnology.com/products/pulsar_lt/
