| |
| Illustration 1 | g06236119 |
|
Left side view (1) Solenoid for the high-pressure fuel pump (2) Atmospheric pressure sensor (3) Fuel rail pressure sensor (4) Intake manifold air pressure sensor (5) Intake manifold air temperature sensor (6) Electronic Control Module (ECM) (7) Oil pressure sensor (8) Crankcase pressure sensor (9) Fuel pressure sensor (secondary filter outlet) (10) Fuel pressure sensor (secondary filter inlet) (11) Fuel temperature sensor (12) Camshaft speed/timing sensor | |
| |
| Illustration 2 | g06236125 |
|
Right side view (13) Coolant temperature sensor (14) Primary speed/timing sensor | |
The electronic control system is designed into the engine fuel system and the engine air inlet and exhaust system. Allowing the electronic control system full control over the fuel delivery and the injection timing. The electronic control system provides improved timing control and fuel air ratio control in comparison to conventional mechanical engines. Injection timing is achieved by the precise control of the injector firing time. Engine rpm is controlled by adjusting the injection duration. The Engine Control Module (ECM) energizes the unit injector solenoids to start the injection of fuel. Also, the ECM de-energizes the unit injector solenoids to stop the injection of fuel.
Refer to Systems Operation, "Fuel System" for a complete explanation of the fuel injection process.
The engine uses the following three types of electronic components:
- Input component
- Control component
- Output component
An input component is one that sends an electrical signal to the ECM of the system. The signal that is sent varies in either of the following ways:
- Voltage
- Frequency
- Pulse width
The variation of the signal is in response to a change in some specific system of the vehicle. Some specific examples of an input component are the engine speed-timing sensors, the coolant temperature sensor, and the cruise control switches. The ECM interprets the signal from the input component as information about the condition, environment, or operation of the vehicle.
A control component (ECM) receives the input signals from the input components. Electronic circuits inside the control component evaluate the signals from the input components. These electronic circuits also supply electrical energy to the output components of the system. The electrical energy that is supplied to the output components is based on predetermined combinations of input signal values.
An output component is one that is operated by a control module. The output component receives electrical energy from the control group. The output component uses that electrical energy in one of two ways. The output component can use that electrical energy to perform work. The output component can use that electrical energy to provide information.
As an example, a moving solenoid plunger will perform work. By performing work, the component has functioned to regulate the vehicle.
As an example, a dash panel light or an alarm will provide information to the operator of the vehicle.
These electronic components provide the electronic control of the engine operation. Engines with electronic controls offer the following advantages:
- Improvement in performance
- Improvement in fuel consumption
- Reduction in emissions levels