Mystery air valve ?

[Yauchout]

(11-02-2024 )marek4792 Wrote:  It almost looks like some sort of abs module like the ones you'd see for steer axle brakes on each side? Maybe for a similar purpose?

My truck does have the Bendix ABS ESP roll stability system but that valve isn't listed anywhere in any of the diagrams I can find and it doesn't look anything like any of the other 6 ABS valves on the truck