A CAN bus transceiver includes CAN bus fault detection circuitry that can provide detailed information to simplify the task of the service technician when there is a CAN bus fault. Voltage and current measurements of the CAN bus are made and from them a fault type is determined. A time-domain reflectometer monitors the CAN bus signals for transmitted and reflected signals and from them a distance to the fault is determined. Either or both values are provided to a service technician to allow error determination and correction.