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.
Adaptive Trim - This is a software process that is performed in the Electronic Control Module (ECM) that optimizes engine performance.
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 dead center position in the normal direction of rotation.
Breakout Harness - A 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.
Code - Refer to "Diagnostic Code" or "Event Code".
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.
Data Link - The Data Link is a serial communication port that is used for communication with other devices such as the electronic service tool.
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 3 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 Code - A diagnostic 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 light. 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.
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 this engine. 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.
Electronic 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 a 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.
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.
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.
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 - Fuel injector E-trim is a software process 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.
FRC - See "Fuel Ratio Control".
Fuel Pump - See "Fuel Rail Pump".
Fuel 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 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 Rail 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 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).
Full Load Setting (FLS) - The FLS is the parameter that represents the fuel system adjustment. This adjustment is made at the factory in order to fine tune the fuel system. 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 in conjunction 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 very 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 measure of electrical frequency in cycles per second.
High Pressure Fuel Rail Pump - See "Fuel Rail Pump".
High Pressure Fuel Rail - See "Fuel Rail".
Injector Codes - The injector codes or injector trim codes are numeric codes or alphanumeric codes that are etched or stamped on individual electronic unit injectors. These codes are used to fine tune the fuel delivery.
Injector Trim Files - Injector trim files are downloaded from a disk to the ECM. The injector trim files compensate for variances in manufacturing of the electronic unit injector and for the life of the electronic unit injector. The serial number for the electronic unit injector must be obtained in order to retrieve the correct injector trim file.
Intake Manifold Air Temperature Sensor - The intake manifold air temperature sensor detects the air temperature in the intake manifold. The ECM monitors the air temperature and other data in the intake manifold in order to adjust injection timing and other performance functions.
Intake Manifold Pressure Sensor - The Intake Manifold Pressure Sensor measures the pressure in the intake manifold. The pressure in the intake 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 the electronic devices.
Logged Diagnostic Codes - Logged diagnostic codes are codes which are stored in the memory. These codes are meant to be an indicator of possible causes for intermittent problems. Refer to the term "Diagnostic Code" in this glossary 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.
Personality Module - See "Flash File".
Position Sensor - This sensor determines the position of the camshaft during start-up. If the speed/timing sensor fails during engine operation, the position sensor is used to provide the signal. The sensor determines the position of the camshaft for injection timing and for engine speed. If the position sensor fails, the engine will continue to operate but the engine will not start.
Power Cycled - Power cycled happens when power to the ECM is cycled: ON, OFF and ON. Power cycled refers to the action of cycling the keyswitch from any position to the OFF position, and to the START/RUN position.
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.
Pump Solenoid Valve - This is a control device in the high pressure fuel rail 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.
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.
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.
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 a sensor that is usually 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.
Timing Calibration - The timing calibration is the adjustment of an electrical signal. This adjustment is made in order to correct the timing error between the camshaft and the engine speed/timing sensors or between the crankshaft and the engine speed/timing sensors.
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 has expired. The glow plugs have not deactivated at this point in time.
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 intake 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 intake manifold pressure to the desired value that is determined by the software.