What should happen if the air pressure in the air brake system tanks falls below 60 psi?

Question

On vehicles with air brakes, a low air pressure warning signal will come on if the pressure in the air tanks falls below 60 psi. On large buses, the signal may activate at 80 to 85 psi.

Accepted Answer

A warning light should come on.

Answer

Lights should flash on the outside of the vehicle.

Answer

A message should appear on the control panel.

Answer

The vehicle should stop.