P-Tronic additional box-units are installed in line between the calculator, whose signal as defined by the manufacturer they receive, and the injection system. A position which guarantees their functioning, even if the cartography is re-initialised. The information they receive is analysed, electronically modified, then sent to the injector pump, to the rail or directly to the injectors, according to model.

On P-Tronic box-units, all connections are made using plugs identical to the originals. This enables rapid installation (2 minutes) with no soldering, and guarantees an optimal connection quality.

The box-units are also systematically programmed to respect the vehicle's tolerances and to keep the 'security mode' system active.