Circuit/System Description

The engine control module (ECM) uses the charge indicator signal circuit, or L-terminal circuit, to control the power output of the generator, and to control the load of the generator on the engine. A high side driver in the ECM supplies voltage to the voltage regulator. This signals the voltage regulator to turn the field circuit ON and OFF. The ECM monitors the state of the charge indicator signal circuit. The ECM should detect low voltage on the charge indicator signal circuit when the ignition is ON and the engine is OFF, or if the generator malfunctions. When the engine is running, the ECM should detect high voltage on the charge indicator signal circuit.