Active Diagnostic Code - An active diagnostic code alerts the operator or the service technician that an electronic system malfunction is currently present. Refer to the term "Diagnostic Code" in this glossary.
Aftertreatment - Aftertreatment is a system that is used to remove pollutants from exhaust gases. The system consists of a Diesel Oxidation Catalyst (DOC) and a Catalyzed Diesel Particulate Filter (CDPF).
Air-To-Air Aftercooler - An air-to-air aftercooler is a device that is used on turbocharged engines in order to cool inlet air that has undergone compression. The inlet air is cooled after the inlet air passes through the turbocharger. The inlet air is passed through an aftercooler (heat exchanger) that uses ambient air for cooling. The inlet air that has been cooled advances to the inlet manifold.
Alternating Current (AC) - Alternating current is an electric current that reverses direction at a regular interval that is reoccurring.
Before Top Center (BTC) - BTC is the 180 degrees of crankshaft rotation before the piston reaches the top center position in the normal direction of rotation.
Boost Pressure - The difference between the turbocharger outlet pressure and atmospheric pressure is commonly referred to as boost pressure. The sensor for the intake manifold air pressure measures the amount of boost.
Breakout Harness - The breakout harness is a test harness that is designed to connect into the engine harness. This connection allows a normal circuit operation and the connection simultaneously provides a Breakout T in order to measure the signals.
Bypass Circuit - A bypass circuit is a circuit that is used as a substitute circuit for an existing circuit. A bypass circuit is typically used as a test circuit.
CAN Data Link (see also J1939 CAN Data Link) - The CAN Data Link is a serial communications port that is used for communication with other microprocessor-based devices.
Catalyzed Diesel Particulate Filter - The Catalyzed Diesel Particulate Filter (CDPF) filters particulates from the exhaust gases. A coating on the internal surfaces reacts with the hot exhaust gases in order to burn off the particulates. This process prevents the CDPF from becoming blocked with soot.
AVSpare NOx Reduction System - The AVSpare NOx Reduction System recycles a portion of the exhaust gases back into the inlet air in order to reduce the amount of nitrous oxide (NOx) in the exhaust gases. The recycled exhaust gas passes through a cooler before being introduced into the inlet air.
Code - Refer to "Diagnostic Code" or "Event Code".
Cold Mode - Cold mode is a mode for cold starting and for cold engine operation. This mode is used for engine protection, reduced smoke emissions, and faster warm-up time.
Communication Adapter Tool - The communication adapter provides a communication link between the ECM and the Electronic Service Tool.
Component Identifier (CID) - The CID is a number that identifies the specific component of the electronic control system that has experienced a diagnostic code.
Coolant Temperature Sensor - The coolant temperature sensor detects the engine coolant temperature for all normal operating conditions and for engine monitoring.
Customer Specified Parameters - A customer specified parameter is a parameter that can be changed in the ECM with the Electronic Service Tool. A customer specified parameters value is set by the customer. These parameters are protected by customer passwords.
Data Link - The Data Link is a serial communication port that is used for communication with other microprocessor-based devices.
Derate - Certain engine conditions will generate event codes. Also, engine derates may be applied. The map for the engine derate is programmed into the ECM software. The derate can be one or more of three types: reduction of rated power, reduction of rated engine speed and reduction of rated machine speed for OEM products.
Desired Engine Speed - The desired engine speed is input to the electronic governor within the ECM. The electronic governor uses the signal from the throttle position sensor, the engine speed/timing sensor, and other sensors in order to determine the desired engine speed.
Diagnostic Trouble Code - A diagnostic trouble code is sometimes referred to as a fault code. These codes indicate an electronic system malfunction.
Diagnostic Lamp - A diagnostic lamp is sometimes called the check engine lamp. The diagnostic lamp is used to warn the operator of the presence of an active diagnostic code. The lamp may not be included in all applications.
Diesel Oxidation Catalyst - The Diesel Oxidation Catalyst is also known as the (DOC). The DOC is a device in the exhaust system that oxidizes certain elements in the exhaust gases. These elements can include carbon monoxide (CO), hydrocarbons and the soluble organic fraction (SOF) of particulate matter.
Digital Sensor Return - The common line (ground) from the ECM is used as ground for the digital sensors.
Digital Sensors - Digital sensors produce a pulse width modulated signal. Digital sensors are supplied with power from the ECM.
Digital Sensor Supply - The power supply for the digital sensors is provided by the ECM.
Direct Current (DC) - Direct current is the type of current that flows consistently in only one direction.
DT, DT Connector, or Deutsch DT - This is a type of connector that is used on the engines. The connectors are manufactured by Deutsch.
Duty Cycle - Refer to "Pulse Width Modulation".
Electronic Engine Control - The electronic engine control is a complete electronic system. The electronic engine control monitors the engine operation under all conditions. The electronic engine control also controls the engine operation under all conditions.
Engine Control Module (ECM) - The ECM is the control computer of the engine. The ECM provides power to the electronics. The ECM monitors data that is input from the sensors of the engine. The ECM acts as a governor in order to control the speed and the power of the engine.
Electronic Service Tool - The electronic service tool allows a computer (PC) to communicate with the ECM.
Engine Monitoring - Engine Monitoring is the part of the electronic engine control that monitors the sensors. This also warns the operator of detected problems.
Engine Oil Pressure Sensor - The engine oil pressure sensor measures engine oil pressure. The sensor sends an electronic signal to the ECM that is dependent on the engine oil pressure.
Engine Speed/Timing Sensor - An engine speed/timing sensor is a Hall effect switch that provides a digital signal to the ECM. The ECM interprets this signal as the crankshaft position and the engine speed. Two sensors are used to provide the speed and timing signals to the ECM. The primary sensor is associated with the crankshaft and the secondary sensor is associated with the camshaft.
Estimated Dynamic Timing - Estimated dynamic timing is the estimate of the actual injection timing that is calculated by the ECM.
Event Code - An event code may be activated in order to indicate an abnormal engine operating condition. These codes usually indicate a mechanical problem instead of an electrical system problem.
Exhaust Back Pressure Valve - The exhaust back pressure valve regulates the gas pressure in the exhaust system. The valve can restrict the flow of exhaust gases in order to increase the exhaust back pressure. An increase in exhaust back pressure will increase the temperature of the exhaust gases which will improve the process that burns off the soot in the CDPF.
Failure Mode Identifier (FMI) - This identifier indicates the type of failure that is associated with the component. The FMI has been adopted from the SAE practice of J1587 diagnostics. The FMI follows the parameter identifier (PID) in the descriptions of the fault code. The descriptions of the FMIs are in the following list.
0 - The data is valid but the data is above the normal operational range.
1 - The data is valid but the data is below the normal operational range.
2 - The data is erratic, intermittent, or incorrect.
3 - The voltage is above normal or the voltage is shorted high.
4 - The voltage is below normal or the voltage is shorted low.
5 - The current is below normal or the circuit is open.
6 - The current is above normal or the circuit is grounded.
7 - The mechanical system is not responding properly.
8 - There is an abnormal frequency, an abnormal pulse width, or an abnormal time period.
9 - There has been an abnormal update.
10 - There is an abnormal rate of change.
11 - The failure mode is not identifiable.
12 - The device or the component is damaged.
13 - The device requires calibration.
14 - There is a special instruction for the device.
15 - The signal from the device is high (least severe).
16 - The signal from the device is high (moderate severity).
17 - The signal from the device is low (least severe).
18 - The signal from the device is low (moderate severity).
19 - There is an error in the data from the device.
31 - The device has failed and the engine has shut down.
Flash File - This file is software that is inside the ECM. The file contains all the instructions (software) for the ECM and the file contains the performance maps for a specific engine. The file may be reprogrammed through flash programming.
Flash Programming - Flash programming is the method of programming or updating an ECM with an electronic service tool over the data link instead of replacing components.
Fuel Injector E-Trim - The fuel injector E-trim is a process in the software that allows precise control of fuel injectors by parameters that are programmed into the ECM for each fuel injector. With the use of the electronic service tool, the service technician can read status information for the E-Trim. Data for E-Trim can also be programmed.
Fuel Injection Pump - This item is sometimes referred to as the High Pressure Fuel Rail Pump. This is a device that supplies fuel under pressure to the fuel rail (high-pressure fuel rail).
Fuel Manifold (Rail) - This item is sometimes referred to as the High Pressure Fuel Rail. The fuel rail supplies fuel to the electronic unit injectors. The fuel rail pump and the fuel rail pressure sensor work with the ECM in order to maintain the desired fuel pressure in the fuel rail. This pressure is determined by calibration of the engine in order to enable the engine to meet emissions and performance requirements.
Fuel Manifold (Rail) Pressure Sensor - The fuel rail pressure sensor sends a signal to the ECM that is dependent on the pressure of the fuel in the fuel rail.
Fuel Ratio Control (FRC) - The FRC is a limit that is based on the control of the ratio of the fuel to air. The FRC is used for purposes of emission control. When the ECM senses a higher intake manifold air pressure (more air into the cylinder), the FRC increases the FRC Limit (more fuel into the cylinder).
The Solenoid Valve for the Fuel Injection Pump - This is sometimes referred to as the High Pressure Fuel Rail Pump Solenoid Valve or the Suction Control Valve. This is a control device in the fuel injection pump. The ECM controls the pressure in the fuel rail by using this valve to divert excess fuel from the pump to the fuel tank.
Full Load Setting (FLS) - The FLS is the number that represents the fuel system adjustment. This adjustment is made at the factory in order to fine-tune the fuel system. The correct value for this parameter is stamped on the engine information ratings plate. This parameter must be programmed.
Full Torque Setting (FTS) - The FTS is the parameter that represents the adjustment for the engine torque. This adjustment is made at the factory in order to fine-tune the fuel system. This adjustment is made with the FLS. This parameter must be programmed.
Glow Plug - The glow plug is an optional starting aid for cold conditions. One glow plug is installed in each combustion chamber in order to improve the ability of the engine to start. The ECM uses information from the engine sensors such as the engine temperature to determine when the glow plug relay must provide power to each glow plug. Each of the glow plugs then provides a hot surface in the combustion chamber in order to vaporize the mixture of air and fuel. This improves ignition during the compression stroke of the cylinder.
Glow Plug Relay - The glow plug relay is controlled by the ECM in order to provide high current to the glow plugs that are used in the starting aid system.
Harness - The harness is the bundle of wiring (loom) that connects all components of the electronic system.
Hertz (Hz) - Hertz is the unit of frequency in cycles per second.
High Pressure Fuel Rail Pump - See "Fuel Injection Pump".
High Pressure Fuel Rail - See "Fuel Manifold (Rail)".
Injector Trim Codes - Injector trim codes are codes that contain 30 characters. The codes are supplied with new injectors. The code is input through the electronic service tool into the ECM. The injector trim codes compensate for variances in the manufacturing of the electronic unit injector and for the life of the electronic unit injector.
Inlet Manifold Air Temperature Sensor - The inlet manifold air temperature sensor detects the air temperature in the inlet manifold. The ECM monitors the air temperature and other data in the inlet manifold in order to adjust injection timing and other performance functions.
Inlet Manifold Pressure Sensor - The Inlet Manifold Pressure Sensor measures the pressure in the inlet manifold. The pressure in the inlet manifold may be different to the pressure outside the engine (atmospheric pressure). The difference in pressure may be caused by an increase in air pressure by a turbocharger (if equipped).
Integrated Electronic Controls - The engine is designed with the electronic controls as a necessary part of the system. The engine will not operate without the electronic controls.
J1939 CAN Data Link - This data link is a SAE standard diagnostic communications data link that is used to communicate between the ECM and other electronic devices.
Logged Diagnostic Codes - Logged diagnostic codes are codes which are stored in the memory. These codes are an indicator of possible causes for intermittent problems. Refer to the term "Diagnostic Code" for more information.
OEM - OEM is an abbreviation for the Original Equipment Manufacturer. This is the manufacturer of the machine or the vehicle that uses the engine.
Open Circuit - An open circuit is a condition that is caused by an open switch, or by an electrical wire or a connection that is broken. When this condition exists, the signal or the supply voltage can no longer reach the intended destination.
Parameter - A parameter is a value or a limit that is programmable. This helps determine specific characteristics or behaviors of the engine.
Password - A password is a group of numeric characters or a group of alphanumeric characters that is designed to restrict access to parameters. The electronic system requires correct passwords in order to change some parameters (Factory Passwords). Refer to Troubleshooting, "Factory Passwords" for more information.
Power Cycling - Power cycling refers to the action of cycling the keyswitch from any position to the OFF position, and to the START/RUN position.
Programmable Software - The software is programmed into the ECM. The software contains all the instructions (software) for the ECM and the software contains the performance maps for a specific engine. The software may be reprogrammed through flash programming.
Primary Speed/Timing Sensor - This sensor determines the position of the crankshaft during engine operation. If the primary speed/timing sensor fails during engine operation, the secondary speed/timing sensor is used to provide the signal.
Pulse Width Modulation (PWM) - The PWM is a signal that consists of pulses that are of variable width. These pulses occur at fixed intervals. The ratio of "TIME ON" versus total "TIME OFF" can be varied. This ratio is also referred to as a duty cycle.
Rated Fuel Limit - This is a limit that is based on the power rating of the engine and on the engine rpm. The Rated Fuel Limit enables the engine power and torque outputs to conform to the power and torque curves of a specific engine model. These limits are in the flash file and these limits cannot be changed.
Reference Voltage - Reference voltage is a regulated voltage and a steady voltage that is supplied by the ECM to a sensor. The reference voltage is used by the sensor to generate a signal voltage.
Relay - A relay is an electromechanical switch. A flow of electricity in one circuit is used to control the flow of electricity in another circuit. A small current or voltage is applied to a relay in order to switch a much larger current or voltage.
Secondary Speed/Timing Sensor - This sensor determines the position of the camshaft during engine operation. If the primary speed/timing sensor fails during engine operation, the secondary speed/timing sensor is used to provide the signal.
Sensor - A sensor is a device that is used to detect the current value of pressure or temperature, or mechanical movement. The information that is detected is converted into an electrical signal.
Short Circuit - A short circuit is a condition that has an electrical circuit that is inadvertently connected to an undesirable point. An example of a short circuit is a wire which rubs against a vehicle frame and this rubbing eventually wears off the wire insulation. Electrical contact with the frame is made and a short circuit results.
Signal - The signal is a voltage or a waveform that is used in order to transmit information typically from a sensor to the ECM.
Suction Control Valve (SCV) - The SCV is a control device in the high-pressure fuel pump. The ECM controls the pressure in the fuel rail by using this valve to control the amount of fuel that enters the chambers in the pump.
Supply Voltage - The supply voltage is a continuous voltage that is supplied to a component in order to provide the electrical power that is required for the component to operate. The power may be generated by the ECM or the power may be battery voltage that is supplied by the engine wiring.
System Configuration Parameters - System configuration parameters are parameters that affect emissions and/or operating characteristics of the engine.
Tattletale - Certain parameters that affect the operation of the engine are stored in the ECM. These parameters can be changed by use of the electronic service tool. The tattletale logs the number of changes that have been made to the parameter. The tattletale is stored in the ECM.
Theft Deterrent - This feature uses a four-digit code in order to prevent the engine from starting. The feature requires a password to be entered via the AVS ID.
"T" Harness - This harness is a test harness that is designed to permit normal circuit operation and the measurement of the voltage simultaneously. Typically, the harness is inserted between the two ends of a connector.
Throttle Position - The throttle position is the interpretation by the ECM of the signal from the throttle position sensor or the throttle switch.
Throttle Position Sensor - The throttle position sensor is an electronic sensor that is connected to an accelerator pedal or a hand lever. This sensor sends a signal to the ECM that is used to calculate desired engine speed.
Throttle Switch - The throttle switch sends a signal to the ECM that is used to calculate desired engine speed.
Top Center Position - The top center position refers to the crankshaft position when the engine piston position is at the highest point of travel. The engine must be turned in the normal direction of rotation in order to reach this point.
Total Tattletale - The total tattletale is the total number of changes to all the parameters that are stored in the ECM.
Wait To Start Lamp - This is a lamp that is included in the cold starting aid circuit in order to indicate when the wait to start period is active. The lamp will go off when the engine is ready to be started. The glow plugs may not have deactivated now.
Wastegate - This is a device in a turbocharged engine that controls the maximum boost pressure that is provided to the inlet manifold.
Wastegate Regulator - The wastegate regulator controls the pressure in the inlet manifold to a value that is determined by the ECM. The wastegate regulator provides the interface between the ECM and the mechanical system that regulates inlet manifold pressure to the desired value that is determined by the software.