The engine is designed for electronic control of most engine operating functions. The electronic system consists of an Electronic Control Module (ECM), the wiring harness, switches, sensors, and fuel injectors. The engine ECM receives information from the sensors and the switches on the engine. The engine ECM processes the information that is collected in order to make decisions on control of the engine. By altering the fuel delivery with the fuel injectors, the engine ECM controls the speed and the power that is produced by the engine.
Electronic Controls
Electronic Control Module
The ECM consists of two main components, the control computer (hardware) and the personality module (flash file). The control computer consists of a microprocessor and electronic circuitry. The flash file contains the engine's operational characteristics. The operating maps influence the engine's performance.
Engine Governor
The engine ECM governs engine speed. The engine ECM and the personality module work together by controlling the amount of fuel that is delivered by the injectors. Desired engine rpm is determined by the throttle position sensor signal and certain sensor readings. Diagnostic codes may derate the engine. Actual engine rpm is measured by the engine speed/timing signal.
Fuel Injection
The engine ECM controls the timing, the duration, and the pressure of the fuel that is injected. The engine ECM varies the signals to the fuel injectors. Fuel is injected only while an injector solenoid is energized by a 105 volt signal from the engine ECM. The timing of the injection signal determines the engine timing. The length of the injection signal determines engine speed. By controlling the timing and duration of the 105 volt signal, the ECM controls the engine speed.
Injection timing depends on the following conditions: desired engine rpm and load. The ECM detects the top center of each cylinder. The ECM sends an injection signal at the desired time.