Patent attributes
A light failure detection system for use in a vehicle having a plurality of light emitting diode lighting devices includes a plurality of voltage level monitoring circuits and plurality of current monitoring circuits for measuring the voltage and current draw of a plurality of lighting circuits. A voltage drop circuit enabling the plurality of voltage level monitoring circuits and the plurality of current monitoring circuits to measure current and voltage at an adjusted input voltage is also provided. The system a learn mode for monitoring the lighting circuits with the plurality of voltage level monitoring circuits and the plurality of current monitoring circuits to determine threshold voltage and current levels for the lighting circuits. An adjusted threshold current, based on a voltage sensitivity and a sensed temperature, is calculated and a fault is indicated when a measured current is above or below the adjusted threshold current by a predetermined value.
