An automobile LED driving device formed as an integrated circuit device comprising: a current setting portion formed within the integrated circuit device and configured to generate a reference current based on a resistor (RL, RH) configured to be connected externally to the automobile LED driving device, a current controller formed within the integrated circuit device and configured to control a current supply to an automobile LED configured to be connected externally to the automobile LED driving device based on the reference current, an output transistor formed within the integrated circuit device and configured to control an output current (IOUT) according to a state of the current controller to the automobile LED, an LED ground short detector formed within the integrated circuit device and configured to detect a first abnormal state of the output current (IOUT) and to generate a first detection signal, an LED open circuit detector formed within the integrated circuit device and configured to detect a second abnormal state of the output current (IOUT) and to generate a second detection signal, characterized by a protect bus controller formed within the integrated circuit device and capable of generating a protect bus signal (PBUS) according to the first or second detection signal (DET1, DET2) and sending the generated protect bus signal (PBUS), the protect bus controller also capable of receiving a protect bus signal (PBUS) generated outside of the automobile LED driving device, and a protect bus terminal configured to send the generated protect bus signal (PBUS) or to receive the protect bus signal (PBUS) generated outside of the automobile LED driving device, wherein, the protect bus controller is configured to generate a forcible off signal based on the protect bus signal (PBUS) and to provide the forcible off signal to the current controller, and wherein the current controller is configured to turn OFF the supply of the output current forcibly, when the forcible off signal indicates an abnormality was detected. a current setting portion formed within the integrated circuit device and configured to generate a reference current based on a resistor (RL, RH) configured to be connected externally to the automobile LED driving device, a current controller formed within the integrated circuit device and configured to control a current supply to an automobile LED configured to be connected externally to the automobile LED driving device based on the reference current, an output transistor formed within the integrated circuit device and configured to control an output current (IOUT) according to a state of the current controller to the automobile LED, an LED ground short detector formed within the integrated circuit device and configured to detect a first abnormal state of the output current (IOUT) and to generate a first detection signal, an LED open circuit detector formed within the integrated circuit device and configured to detect a second abnormal state of the output current (IOUT) and to generate a second detection signal, a protect bus controller formed within the integrated circuit device and capable of generating a protect bus signal (PBUS) according to the first or second detection signal (DET1, DET2) and sending the generated protect bus signal (PBUS), the protect bus controller also capable of receiving a protect bus signal (PBUS) generated outside of the automobile LED driving device, and a protect bus terminal configured to send the generated protect bus signal (PBUS) or to receive the protect bus signal (PBUS) generated outside of the automobile LED driving device, wherein, the protect bus controller is configured to generate a forcible off signal based on the protect bus signal (PBUS) and to provide the forcible off signal to the current controller, and wherein the current controller is configured to turn OFF the supply of the output current forcibly, when the forcible off signal indicates an abnormality was detected.