A lighting circuit for blinking a light-emitting unit having plural light sources is equipped with an abnormality detection unit which generates abnormality information when detecting an abnormality in even one of the plural light sources, and a holding circuit which holds the abnormality information during a period when the lighting circuit is supplied with a blinking signal, The lighting circuit supplies a drive current(s) to the plural light sources according to the blinking signal and stops supplying a drive current(s) to all of the plural light sources according to the abnormality information being held by the holding circuit.

A lighting circuit applied to a vehicle lighting tool includes: a power supply line to which power supply voltage is supplied in a first period of time out of a predetermined cycle including the first period of time and a second period of time, the supply of the power supply voltage being stopped in the second period of time; a regulator that supplies driving current to a light source based on the power supply voltage across the power supply line; a detection circuit that detects whether there is an abnormality in the light source; a signal output circuit that operates based on the power supply voltage across the power supply line and outputs a signal according to a detection result of the detection circuit; and a control circuit that stops an operation of the regulator when the signal indicating that there is an abnormality in the light source is output.

An LED lighting device system for a vehicle prevents erroneous lighting of the LED lighting device due to leakage current at fee operation switch. An LED lighting device system for a vehicle is provided with an LED lighting device having an LED light source, an operation switch for lighting and extinguishing the LED light source, and a power source that is connected to the input side of the operation switch and feeds electrical current to the LED light source. The LED light device system for a vehicle has a switching element capable of blocking electrical current flowing to the LED light source and a detection unit that detects voltage on the output side of the operation switch and causes the switching element to block the electrical current.

A combination switch 10 outputs operation command signals to a driving system of a vehicle according to a switching operation of a switching unit 11 and includes a storage part 21 that stores determination information 21a indicating whether combinations of operation command signals to be outputted from switches of the switching unit 11 are abnormal or normal, a determination part 22 that refers to the determination information 21a in the storage part 21, determines whether or not a combination of the operation command signals is abnormal, and if an abnormal combination of the operation command signals continues longer than a predetermined time, adds, to the operation command signals, abnormality information indicating that the combination of the operation command signals is abnormal, and a communication part 13 that transmits the operation command signals added with the abnormality information.

A directional indicator system includes a directional indicator that includes a plurality of LED series circuits each connected in parallel to another of the LED series circuits. Each LED series circuit includes LEDs connected in series. A driver is configured to control driving of the directional indicator. The driver includes LED drivers that are each configured to drive a corresponding one of the LED series circuits. The driver also includes a plurality of current detectors that are each configured to measure a value of a current in a corresponding one of the LED series circuits.

A towing vehicle includes a towing control unit with circuitry to detect whether a light is connected to the electrical harness electrically coupling the vehicle to the trailer. The towing control unit may include lamp connectivity circuits for, for example, the left turn signal and the right turn signal. To determine whether the turn light is connected, the corresponding connectivity circuit periodically generates a test signal. Based on characteristics of a response signal to the test signal. The connectivity circuit determines whether the corresponding turn signal light of the trailer is connected based on a response to the test signal. The connectivity circuit may distinguished whether an incandescent-based turn signal light, a light emitting diode (LED)-based turn signal light, and an open circuit is sensed based on the characteristics of the response signal.

A system and method are provided for reducing a power consumption of a vehicle rear lamp. A vehicle data bus, a power supply, at least one light source, and at least one rear lamp control unit are provided. The at least one rear lamp control unit is connected to the light source, and is adapted to power the light source. The rear lamp control unit is connected to the vehicle data bus and the power supply. A switch and a switch control unit are also provided, with the switch control unit being connected to the switch and adapted to close the switch and to open the switch. The switch is connected between the power supply and the rear lamp control unit. The switch control unit is connected to the vehicle data bus.

A method for operating at least one direction indicator of a motor vehicle, wherein, as of an actuation time, the direction indicator outputs a light signal comprising a periodic repetition of alternately successive on-phases and off-phases. A discrepancy of a starting phase angle of the light signal with respect to a predefined reference signal is determined at the actuation time and is compared with a predefined target phase angle assigned to the direction indicator. When there is a phase offset between the starting phase angle and the target phase angleat least two of the on-phases and/or the off-phases of the light signal are extended or shortened by a different time difference value in each case after the actuation time such that the phase angle of the light signal with respect to the reference signal then corresponds to the predefined target phase angle, and/orthe light signal is started with a first off-phase (11) at the actuation time. The duration of the first off-phase corresponds to a time offset corresponding to the phase offset between the starting phase angle and the predefined target phase angle, with the result that an on-phase of the light signal following the first off-phase is at the target phase angle with respect to the reference signal.

Embodiments relate to a system and method of providing an alert to another vehicle that has a malfunction, in the visual display. The method includes obtaining, using a sensor, data of a primary vehicle, identifying, based on the obtained data, a malfunction of the primary vehicle, and establishing communication via a communication module, with the primary vehicle. The method further includes transmitting an alert message to the primary vehicle, wherein, the alert message comprises a malfunction information of the malfunction.

Embodiments relate to a system and method of receiving an indication that visual displays are malfunctioning and take corrective action. The method includes receiving via a communication module of a primary vehicle, an alert message from a secondary vehicle, wherein the alert message comprises malfunction information of the primary vehicle, validating using a diagnostics module of the primary vehicle, the malfunction information, and confirming using the diagnostics module, a malfunction of the primary vehicle. The method further includes determining a corrective action based on diagnostic information from the diagnostic module.