Light detection and ranging system comprising: at least one light source for emitting a light pulse to the surroundings of the light detection and ranging system, at least one monitoring optical sensor for monitoring the emitting of the light pulse by the at least one light source, at least one receiving optical sensor for receiving a light signal from the surroundings of the light detection and ranging system, at least one signal processing unit for processing the signal of the at least one receiving optical sensor, and a control unit for controlling the at least one light source, the at least one monitoring optical sensor, the at least one receiving optical sensor and the at least one signal processing unit including a multiplexer, wherein the at least one signal processing unit comprises the multiplexer at the input for multiplexing between the signal of the at least one receiving optical sensor and the signal of the at least one monitoring optical sensor, wherein the signal of the at least one receiving optical sensor is used to detect objects in the surroundings of the light detection and ranging system and the signal of the at least one monitoring optical sensor is compared to an expected signal to provide a self-check function for the at least one light source and the at least one signal processing unit, wherein the light detection and ranging system comprises multiple receiving optical sensors, characterized in that the light detection and ranging system comprises a separate signal processing unit for each receiving optical sensor, wherein each signal processing unit comprises a separate multiplexer at the input for multiplexing between the signal of the at least one receiving optical sensor and the signal of the at least one monitoring optical sensor, wherein the light detection and ranging system can distinguish between errors of the at least one light source and errors of the separate signal processing units by processing the signal of the monitoring optical sensor by the separate signal processing units, wherein if all signal processing units indicate the same error this is due to an error of the at least one light source and if only one or a few of the signal processing units indicate an error this is due to an error of the respective signal processing unit. at least one light source for emitting a light pulse to the surroundings of the light detection and ranging system, at least one monitoring optical sensor for monitoring the emitting of the light pulse by the at least one light source, at least one receiving optical sensor for receiving a light signal from the surroundings of the light detection and ranging system, at least one signal processing unit for processing the signal of the at least one receiving optical sensor, and a control unit for controlling the at least one light source, the at least one monitoring optical sensor, the at least one receiving optical sensor and the at least one signal processing unit including a multiplexer, wherein the at least one signal processing unit comprises the multiplexer at the input for multiplexing between the signal of the at least one receiving optical sensor and the signal of the at least one monitoring optical sensor, wherein the signal of the at least one receiving optical sensor is used to detect objects in the surroundings of the light detection and ranging system and the signal of the at least one monitoring optical sensor is compared to an expected signal to provide a self-check function for the at least one light source and the at least one signal processing unit, wherein the light detection and ranging system comprises multiple receiving optical sensors, characterized in that the light detection and ranging system comprises a separate signal processing unit for each receiving optical sensor, wherein each signal processing unit comprises a separate multiplexer at the input for multiplexing between the signal of the at least one receiving optical sensor and the signal of the at least one monitoring optical sensor, wherein the light detection and ranging system can distinguish between errors of the at least one light source and errors of the separate signal processing units by processing the signal of the monitoring optical sensor by the separate signal processing units, wherein if all signal processing units indicate the same error this is due to an error of the at least one light source and if only one or a few of the signal processing units indicate an error this is due to an error of the respective signal processing unit.