The driver of the vehicle will select an appropriate tire pressure from inside the vehicle; however if for example the vehicle is being driven at a high speed for a considerable amount of time, a speed sensor will detect that more air is needed to be added to the tire as this will prevent unnecessary tire damage. The speed sensor will then send the information to the electronic control unit which will then allow a valve to isolate that particular tire and allow inflation.
The main components of a CTIS are the electronic control unit which sends information to the drivers control unit on the dash board, which allows the driver to monitor the system. The electronic control unit also checks for tire pressure approximately every ten minutes, and then sends this information to the pneumatic control unit. The pneumatic control unit monitors and controls the air pressure and the wheel valves. This unit also sends tire pressure readings back to the electronic control unit. The wheel valves can be found on the exterior of each wheel. These valves isolate the particular wheel that need inflation or deflation, and allows air in or out of the tire using a tube that is run from an air compressor. A CTIS system works by taking the air from a compressor, which is normally the same compressor that is used for the brake system. A pressure switch is used to control the air for the brake system prior to using the air for the tires, which maintains the brake system as a priority.
