Control of the intensity of a led lighting system

There is described a system and method for controlling the intensity of a lighting system for vehicles comprising light emitting diodes mounted on printed circuit boards (PCBs). The method comprises sending a first modulation signal to the lighting modules from a master controller upon detection of a presence of power from a power source by the master controller; and sending a second modulation signal to the lighting modules from the master controller upon detection of an absence of power from a power source by the master controller. The first modulation signal corresponds to a first LED intensity and the second modulation signal corresponds to a second LED intensity lower than the first light intensity.