C-15 Petroleum Engine Caterpillar

Illustration 1	g01052175

Show/hide table

The connection of any electrical equipment and the disconnection of any electrical equipment may cause an explosion hazard which may result in injury or death. Do not connect any electrical equipment or disconnect any electrical equipment in an explosive atmosphere.

Major components of the electronic control system are identified in Illustration 1.

The electronic control system is designed into the engine's fuel system. The electronic control system is also designed into the air inlet and exhaust system. The system is designed to electronically control the delivery of fuel and injection timing. The system provides increased control of the timing and the fuel ratio control when the system is compared to conventional mechanical engines. Injection timing is achieved by precise control of injector firing time. Engine speed is controlled by adjusting the firing duration. The Electronic Control Module (ECM) energizes the fuel injector solenoids in order to start fuel injection. The ECM de-energizes the fuel injector solenoids to complete fuel injection. Refer to the Systems Operation, "Fuel System" topic for a complete explanation of the fuel injection process.

The engine uses three types of electronic components:

• Input

• Control

• Output

An input component sends an electrical signal to the engine system's ECM. The signal varies in either voltage or frequency in response to a change in a specific system. The ECM sees the input signal from the sensor as information about the engine. The information may be about the condition, environment, or operation of the engine.

The ECM receives the input signals. Electronic circuits inside the ECM evaluate the signals from each of the input components. These electronic circuits also provide control signals to the output components of the system. The control signals that are supplied to the output components are in response to strategically predetermined combinations of input signal values.

An output component is one that responds to a control signal that is sent by the ECM. Upon the receipt of the control signal, the output device performs one of the following tasks:

• Perform work such as energizing the fuel injector solenoid which starts the fuel injection, taking an active part in regulating or operating the engine.

• Give information or warning to the operator of the engine.

Table 1 lists the electrical connectors and functions for the engine.