Injection Actuation Pressure Control System

TM 9-2320-312-24-2

Troubleshooting Section

The service brake is depressed.

The "Rated Fuel Limit" is a limit that is based on

the power rating of the engine and engine rpm.

The clutch pedal is depressed.

The "Rated Fuel Limit" is similar to the rack stops

and the torque spring on a mechanically governed

The automatic transmission is placed in gear.

engine. The "Rated Fuel Limit" provides the power

curves and the torque curves for a specific engine

family and a specific engine rating. All of these

Customer Parameters and Engine Speed

limits are determined at the factory. These limits are

Governing

in the personality module and these limits cannot

be changed.

A unique feature with electronic engines is

Customer Specified parameters. These parameters

Injection Actuation Pressure Control

allow the vehicle owner to fine tune the ECM for

System

engine operation. Fine tuning the ECM for engine

operation allows the vehicle owner to accommodate

the typical usage of the vehicle and the power train

The ECM controls fuel injection by controlling oil

of the vehicle.

pressure to the fuel injectors. The pressure of the

oil in the high pressure oil manifold is controlled by

Many of the customer parameters provide additional

the ECM through control of the injection actuation

restrictions on the actions that will be performed

pressure control valve. The injection actuation

by the ECM in response to the driver's input. For

pressure control valve (dump valve) controls the

example, the "PTO Top Engine Limit" is an engine

high pressure pump outlet pressure by dumping

rpm limit. The "PTO Top Engine Limit" is an engine

excess flow back to the oil sump.

rpm limit that is used by the ECM as a cutoff for

the fuel. The ECM will not fuel the injectors above

The ECM monitors the pressure in the high pressure

this rpm.

manifold through the injection actuation pressure

sensor. The injection actuation pressure sensor is

Some parameters are intended to notify the

located in the top of the manifold on the left side

driver of potential engine damage (Engine

of the engine. The injection actuation pressure

Monitoring Parameters). Some parameters enhance

sensor's signal is compared by the ECM to the

fuel economy (Vehicle Speed, Cruise Control,

desired injection actuation pressure. The injection

Engine/Gear Speed Limit Parameter and Idle

actuation pressure sensor's signal is based on

Shutdown). Other parameters are used to enhance

sensor inputs. The sensor inputs are used to adjust

the engine installation into the vehicle. Other

the position of the injection actuation pressure

parameters are also used to provide engine

control valve in order to adjust the oil pressure in

operating information to the truck engine owner.

the high pressure manifold.

High pressure oil is routed from the pump to the

Engine Monitoring

high pressure manifold through a steel tube. From

the manifold, the oil is routed to each injector

Caterpillar provides a factory installed engine

through the high pressure oil manifold. All injectors

monitoring system. The Caterpillar Engine

have a constant supply of oil while the engine

Monitoring system monitors the following variables:

is running. Disabling the electrical signal to the

injector solenoid does not interrupt the oil flow to

Coolant temperature

the fuel injector.

Inlet manifold air temperature

Cold Mode

Coolant level (optional variable)

Cold Mode is activated when the sum of coolant

temperature and the inlet manifold air temperature

Engine oil pressure (optional variable)

is below 18 C (64 F). When Cold Mode begins,

the idle rpm speed ramps up to the default value

Caterpillar Engine Monitoring can be programmed

of 1000 rpm unless another value has been

to four different modes. The four modes of

programmed into the "Warm Up Mode Idle Speed"

programming are "OFF", "WARNING", "DERATE",

parameter. Cold Mode stays active until any of the

and "SHUTDOWN". The sensors will operate in the

following conditions are met:

engine monitoring mode that is selected.

The sum of coolant temperature and the inlet

manifold air temperature reaches 18 C (64 F).

12 minutes have expired.