The Used Caterpillar 3406E ECM 40-Pin 117-8351-00 is a performance part that requires programming and has a pin terminal type. It is a vintage part that is not universally fitting, but rather designed for specific Caterpillar engines. This engine control unit (ECU) is manufactured in the United States and features easy installation. With 40 terminals and dimensions of 14 inches in length, 3 inches in height, and 10 inches in width, this ECM is a reliable choice for Caterpillar engine control.