3176B MARINE ENGINE Caterpillar

7.0 Glossary Of Terms

Usage:

After Market Device

As used here, a device or accessory installed by the customer or vessel OEM after the engine is delivered.

Air-To-Air Aftercooler (ATAAC)

A means of cooling intake air after the turbocharger, using ambient air for cooling. The intake air is passed through an aftercooler (heat exchanger) mounted in front of the radiator before going to the intake manifold.

Alternating Current (AC)

The direction of current flow changes (alternates) regularly and constantly.

American Wire Gauge (AWG)

A measure of the diameter (and therefor the current carrying ability) of electrical wire. The smaller the AWG number, the larger the wire.

Atmospheric Pressure Sensor

This sensor measures atmospheric air pressure and sends a signal to the ECM.

Before Top Center (BTC)

The 180 degrees of crankshaft rotation before the piston reaches Top Center (normal direction of rotation).

Boost Pressure Sensor

This sensor measures inlet manifold air pressure and sends a signal to the ECM.

Bypass Circuit

A circuit, usually temporary, to substitute for an existing circuit, typically for test purposes.

Calibration

As used here, is an electronic adjustment of a sensor signal.

Caterpillar Engine Monitoring

The part of the Caterpillar Electronic Engine Control that monitors Coolant Temperature, Oil Pressure, Intake Manifold Air Temperature and Coolant Level to flag the operator of detected problems. The Coolant Temperature, Intake Manifold Air Temperature, and Oil Pressure Sensors are supplied by Caterpillar and monitored by the ECM. The Coolant Level Sensor is Vessel OEM installed, but still monitored by the ECM. This is opposed to an After Market Engine Monitoring System which does not interface with the Caterpillar Electronic Engine Control.

Check Engine Lamp

Sometimes referred to as the "Diagnostic Lamp", it is used to warn the operator of the presence of an active diagnostic code.

Coolant Level Sensor

This OEM installed sensor detects the absence/presence of coolant at the probe and sends a signal to the ECM.

Code

See Diagnostic Code.

Coolant Temperature Sensor

This sensor detects the engine coolant temperature for Cold Mode operation and Caterpillar Engine Monitoring (if Engine Monitoring is not programmed OFF).

Customer Specified Parameter

A Parameter that can be changed and whose value is set by the customer. Protected by Customer Passwords.

Data Link

An electrical connection for communication with other microprocessor based devices that are compatible with the American Trucking Association and SAE Standard such as trip recorders, electronic dashboards, powertrain controls, and maintenance systems. The Data Link is also the communication medium used for programming and troubleshooting with Caterpillar devices.

Desired RPM

An input to the electronic governor within the ECM. The electronic governor uses inputs from the Throttle Position Sensor, Engine Speed/Timing Sensor and Customer Parameters to determine "Desired RPM".

Desired Timing Advance ("Des Timing Adv" on ECAP)

The injection timing advance calculated by the ECM as required to meet emission and performance specifications.

Diagnostic Code

Sometimes referred to as a "fault code". It is an indication of a problem or event in the 3176B System.

Diagnostic Event Code

These codes indicate an event, such as an Idle Shutdown Occurrence has happened. They are not necessarily (or usually) an indication of problem within the 3176B Electronic System.

Diagnostic Fault Code

These codes indicate an electronic system malfunction indicating a problem with the 3176B Electronic System.

Diagnostic Flash Code

These codes are flashed out via the Check Engine/Diagnostic Lamp to indicate an electronic system malfunction or an event detected by the 3176B Electronic System.

Diagnostic Lamp

Sometimes referred to as the "check engine light", it is used to warn the operator of the presence of an active diagnostic code.

Direct Current (DC)

The type of current where the direction of current flow is consistently in one direction only.

Duty Cycle

See Pulse Width Modulation.

Electronic Control Analyzer Programmer (ECAP)

An electronic service tool developed by Caterpillar used for programming and diagnosing a variety of Caterpillar electronic controls.

Electronic Control Module (ECM)

The engine control computer that provides power to the 3176B electronics, monitors 3176B inputs and acts as a governor to control engine rpm.

Electronic Engine Control (3176B)

The complete electronic system that monitors and controls engine operation under all conditions.

Electronically Controlled Unit Injector

The injection pump which is mechanically actuated, electronically controlled unit injector combining the pumping, electronic fuel metering and injecting elements in a single unit.

Engine Speed/Timing Sensor

Provides a Pulse Width Modulated Signal to the ECM, which the ECM interprets as crankshaft position and engine speed.

Estimated Dynamic Timing

The ECM's estimation of actual injection timing.

Failure Mode Identifier (FMI)

Type of failure the component experienced (adopted from SAE standard practice J1587 diagnostics).

(FMI) Description

0 Data valid but above normal operational range

1 Data valid but below normal operational range

2 Data erratic, intermittent, or incorrect

3 Voltage above normal or shorted high

4 Voltage below normal or shorted low

5 Current below normal or open circuit

6 Current above normal or grounded circuit

7 Mechanical system not responding properly

8 Abnormal frequency, pulse width, or period

9 Abnormal update

10 Abnormal rate of change

11 Failure mode not identifiable

12 Defective device or component

13 Uncalibrated device or component

14 Reserved for future assignment

15 Reserved for future assignment

Flash Code (FC)

The Caterpillar proprietary code numbers which are flashed out on the 3176B diagnostic lamp.

Fuel Ratio Control (FRC)

FRC Fuel Pos. - is a limit based on control of the fuel to air ratio and is used for emissions control purposes. When the ECM senses a higher boost pressure (more air into cylinder), it increases the "FRC Fuel Pos" limit (allows more fuel into cylinder).

Fuel Position

An internal signal within the ECM, from the Electronic Governor to Fuel Injection Control. It is based on desired rpm, FRC Fuel Position, rated fuel position and engine rpm. Reference "3176B System Overview" in Section 1 of this manual.

Fuel Temperature

This sensor detects the fuel temperature. The ECM monitors the fuel temperature and adjusts calculated fuel rate accordingly.

Harness

The wiring bundle (loom) connecting all components of the 3176B System.

Hertz (Hz)

Measure of frequency in cycles per second.

Intake Manifold Air Temperature Sensor

This sensor detects the intake manifold air temperature. The ECM monitors the inlet air temperature and coolant temperature to adjust injection timing. It is also part of Caterpillar Engine Monitoring.

Oil Pressure Sensor

This sensor measures engine oil pressure and sends a signal to the ECM as part of Caterpillar Engine Monitoring.

Open Circuit

Condition where an electrical wire or connection is broken, so that the signal or the supply voltage can no longer reach its intended destination.

Original Equipment Manufacturer (OEM)

As used here, the manufacturer of a vessel in which a Caterpillar engine is installed.

Parameter

A programmable value which affects the characteristics or behavior of the engine and/or vessel.

Password

A group of numeric or alpha-numeric characters, designed to restrict access to parameters. The 3176B System requires correct passwords in order to change Customer Specified Parameters (Customer Passwords) or certain engine specifications (Factory Passwords). Passwords are also required to clear certain diagnostic codes.

Personality Module or Ratings Personality Module

The module attached inside of the ECM which contains all the instructions (software) for the ECM and performance maps for a specific horsepower family.

Parameter Identifier (PID)

Two or three digit code which is assigned to each component.

Pulse Width Modulation (PWM)

A signal consisting of variable width pulses at fixed intervals, whose "TIME ON" versus "TIME OFF" can be varied (also referred to as "duty cycle").

Rated Fuel Position

("Rated Fuel Pos" on ECAP) - this indicates the maximum allowable fuel position (longest injection pulse). It will produce rated power for this engine configuration.

Reference Voltage

A regulated voltage supplied by the ECM to a sensor. The reference voltage is used by the sensor to generate a signal voltage.

Throttle Position Sensor

This sensor measures throttle position and sends a signal to the ECM. The sensor is mounted off of the throttle assembly. The throttle lever is connected through an adjustable linkage to this throttle.

Retarder Enable Signal

The retarder enable signal interfaces the ECM to the engine retarder. This will prohibit operation of the engine brake during undesirable engine operating conditions (such as while the engine is being fueled).

Sensor

A device used to detect and convert a change in pressure, temperature, or mechanical movement into an electrical signal.

Service Program Module

A software program on a factory programmable computer chip, designed to adapt an ECAP to a specific application.

Short Circuit

A condition where an electrical circuit is unintentionally connected to an undesirable point. Example: a wire which rubs against a vessel frame until it wears off its insulation and makes electrical contact with the frame.

Signal

A voltage or waveform used to transmit information typically from a sensor to the ECM.

Subsystem

As used here, it is a part of the 3176B System that relates to a particular function, for instance: throttle subsystem, etc.

Supply Voltage

A constant voltage supplied to a component to provide electrical power for its operation. It may be generated by the ECM, or it may be vessel battery voltage supplied by the vessel wiring.

"T" Harness