Troubleshooting Section

TM 9-2320-312-24-2

Troubleshooting Section

The electronic control system uses the actual

conditions and the desired conditions in order to

make the decisions. The electronic control system

controls the engine during starting and operation.

Electronic Troubleshooting

i01857056

System Overview

SMCS Code: 1900

System Operation

The engine uses a Hydraulic Electronic Unit Injector

fuel system. The injection pump, the fuel lines and

the nozzles that are used in mechanical engines

have been replaced with an hydraulic electronic

unit injector in each cylinder. A solenoid on each

injector controls the amount of fuel that is delivered

by the injector. An axial piston pump increases the

engine oil pressure in order to activate the injector.

An Engine Control Module (ECM) sends a signal

to the injection actuation pressure control valve in

order to control injection pressure. Another electrical

g00693055

Illustration 1

signal is sent to each injector solenoid in order to

inject fuel.

The governor considers the desired conditions

and the actual conditions. The governor then takes

Electronic Controls

the action that best accommodates the desired

conditions. The desired conditions are typically

The engine's electronic system consists of the

the accelerator pedal position, the desired vehicle

Engine Control Module (ECM), the engine sensors,

speed during cruise control, or the desired engine

the injection actuation pressure control valve, and

speed during PTO control. The actual conditions

the vehicle interface. The ECM is the computer. The

are based on current operating conditions such as

personality module is the software for the computer.

coolant temperature, load conditions, etc.

The personality module contains the operating

maps. The operating maps define the following

Timing Considerations

characteristics of the engine:

Once the ECM has determined the amount of fuel

Horsepower

that is required, the ECM must then determine

when the injection is needed. Injection timing is

Torque curves

determined by the ECM after considering input

from the coolant temperature sensor, the sensor for

Engine speed (rpm)

the intake air temperature, and the boost pressure

sensor.

Engine Governor

The electronic controls on the engine serves as

the engine governor. The electronic control system

determines:

The timing of the fuel delivery to the cylinders

The amount of fuel that is delivered to the

cylinders

Injection pressure