ELECTRICAL SYSTEM CONTINUED
Engine Electronic Control System Components
The electronic control system has the following major components:
Speed sensor or timing sensor
Coolant temperature sensor
Inlet air temperature sensor
Boost pressure sensor
Fuel temperature sensor
Atmospheric pressure sensor
Oil pressure sensor
Engine wiring harness
Electronic Control Module (ECM)
A remote mounted throttle position sensor
The electronic control system is integrally designed into the engine's fuel system and the engine's air inlet and
exhaust system in order to control fuel delivery and injection timing electronically. The electronic control system
provides increased timing control and fuel air ratio control in comparison to conventional mechanical engines.
Injection timing is achieved by precise control of injector firing time, and engine RPM is controlled by adjusting the
firing duration. The ECM energizes the solenoid in the unit injector in order to start the injection of fuel and de-
energizes the unit injector solenoids in order to stop injection of fuel.
The engine uses the following three types of electronic components:
An input component is one that sends a signal to the electronic control module of the system. The signal that is
sent varies in either voltage or frequency. The variation of the signal is in response to a change in some specific
system of the vehicle. The electronic control module sees the input sensor signal as information about the
condition, environment, or operation of the vehicle.
A control component receives the input signals. Electronic circuits inside the control 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
An output component is one that is operated by a control module. The output component receives electrical energy
from the electronic control group. The output component uses the electrical energy in one of two ways. The output
component can use that electrical energy in order to perform work or to provide information.
1. A moving solenoid plunger will perform work by functioning to regulate the vehicle.
2. A dash panel light or an alarm will provide information to the operator of the vehicle.