When a driver is using the trailer hand brake valve to stop a rig and then stomps on the treadle valve,what is the source of the trailer service control signal?

Question

Quizplus · Accepted Answer

The trailer service control signal comes from the tractor primary circuit when a driver uses the trailer hand brake valve and then applies the treadle valve. This is because the primary circuit is responsible for controlling the braking system in a tractor-trailer setup, ensuring that the signal for braking is properly communicated from the tractor to the trailer.

When a Driver Is Using the Trailer Hand Brake Valve