Rosequartz Smart Keymaker OBD Diagnostic Tool for Toyota 4C and 4D Chip This is Smart Keymaker OBD Diagnostic Tool for Toyota 4C and 4D Chip. Toyota Smart Keymaker OBD for 4D Chip support Toyota and Lexus smart key system support K line and CAN-BUS protocols. It is a safe and fast key programmer for Toyota and Lexus 4D chip.