Engine Control Unit (ECU)/power system The Engine Control Unit (ECU) coordinates all print engine activities, drives the laser, and coordinates print data from the formatter with the image formation process. The ECU also includes power supply and distribution circuitry. The ECU controls the following systems and functions: • Printer engine control • printer laser/scanner drive • paper motion monitoring and control • motor • Power system • AC power distribution • DC power distribution • overvoltage/undervoltage protection • high-voltage power distribution Figure 3-3 ECU loads 44 Functional Overview C4224-90962