Brake controller mounted to a towing vehicle

A brake controller for a towed vehicle braking system, wherein the towed vehicle has combined brake and turn lights activated by combined light signals from a towing vehicle, said brake controller configured to generate a braking control signal to the towed vehicle braking system, the brake controller including:

• an inertial sensor including plural sensor axes for generating sensor data associated with each sensor axis;
• a processor for processing said sensor data to estimate a deceleration of the towing vehicle;
• and
• a housing including an input connector for electrical connection to a towing vehicle and an output connector for electrical connection to a towed vehicle,
• wherein the housing is adapted to be mounted to the towing vehicle,
• wherein the inertial sensor and the processor are housed within the housing, and the brake controller is electrically connected to the towing vehicle via the input connector and to the towed vehicle via the output connector, and wherein the output connector includes an output socket adapted to receive a plug from the towed vehicle,
• whereby the brake controller is configured to generate and output the braking control signal to control activation of brakes of the towed vehicle braking system based on the deceleration of the towing vehicle estimated by the processor and a brake light signal determined by the processor from received combined light signals from the towing vehicle via the input connector,
• wherein the brake controller receives power via the input connector for some or all components of the brake controller and for auxiliary devices of the towed vehicle, and
• wherein the processor monitors current drawn by the auxiliary devices of the towed vehicle, and the brake controller reserves current for braking control by disconnecting one or more auxiliary devices or trailer lighting circuits.