Illustration 6 Electronic control system components (top view)

TM 9-2320-312-24-2

Systems Operation Section

g00292594

Illustration 6

Electronic control system components (top view)

(11) Injection actuation pressure control

(5) Atmospheric pressure sensor (if

(1) Grommet for injector harness

valve

equipped)

(2) Injection actuation pressure sensor

(16) Relay for the air inlet heater

(6) Boost pressure sensor

(3) Air inlet heater

(8) Engine ground stud connection

(4) Inlet air temperature sensor

Output component

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 electronically

An input component is one that sends an electrical

control the fuel delivery and the injection timing. The

signal to the ECM of the system. The signal that is

electronic control system provides increased timing

sent varies in either of the following ways:

control and fuel air ratio control in comparison to

Voltage

conventional mechanical engines. Injection timing

is achieved by the precise control of the injector

Frequency

firing time. Engine rpm is controlled by adjusting

the injection duration. The Engine Control Module

Pulse width

(ECM) energizes the unit injector solenoids in

order to start the injection of fuel. Also, the Engine

Control Module (ECM) de-energizes the unit injector

The variation of the signal is in response to a

solenoids in order to stop the injection of fuel.

change in some specific system of the vehicle.

Some specific examples of an input component

Refer to Systems Operation/Testing And Adjusting,

are the engine speed-timing sensors, the coolant

"HEUI Injector Operation" for a complete explanation

temperature sensor, and the cruise control switches.

of the fuel injection process.

The ECM interprets the signal from the input

component as information about the condition,

The engine uses the following three types of

environment, or operation of the vehicle.

electronic components:

Input component

Control component