Mystery Knob on Dash 2022

Just bought a low-mile 2022 Access cab/V6/RWD. I cannot find a reference in the owner's manual to the knob pictured, unless I missed it somewhere in the 600+ pages.
It is to the left of the steering wheel next to the traction control switch. It rotates with little resistance and has an index mark on it.
Anyone know what this does?
Thanks much.

 

My guess is subwoofer bass controller or trailer controller, neither are stock options though

 

They’re watching you.

 

Its aftermarket

 

That's a sub control.

 

Ejecto seato.

 

Drive on the ceiling of tunnels.

 

Wrong answers only?

 

Auto suck!

 

Hydraulics probably

 

You could disassemble your truck interior and other parts tracking down the wires.

 

Turn it and see. Sub control sounds legit so try it with the stereo on.

 

O.K., it must be for the JL Stealthbox that I uninstalled as soon as I got the truck home. To evoke the Byrds, it weighed 500 lbs. and slept on the floor. I'm too old for all that bass.

 

Back massager control..

 

It’s the prostate rattler control knob

 

dims the dash lights

 

If you remove that JL audio bass control knob, I'll gladly take it off your hands!

 

JL bass knob. Remove it and you will see a jack for a telephone cord.

 

Auto-decompression knob. If you stall the truck, you turn it while trying to kickstart again.

 

Clearly it’s a vernier adjustment knob. Turn it clockwise to increase or counter-clockwise to decrease the magnitude.