OTC (3415) CAN Test Box - Breakout Box and Protocol Detector Used for diagnosing electrical faults and CAN bus line activity Check power and ground circuits, check active protocol lines, or connect a multimeter or oscilloscope for detailed signal analysis Connect, detect, monitor voltage and more Connects between Diagnostic Link Connector (DLC) and scan tool Detects data and protocol communication and monitors system voltage with a display and high/low alarm