Engine Operation 52 UENR0623-02 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. Harness – The harness is the bundle of wiring (loom) that connects all components of the electronic system. Hertz (Hz) – Hertz is the measure of frequency in cycles per second. Oxygen Sensor – The oxygen sensor detects the level of oxygen. The level of oxygen is inputted to the combustion control. High Pressure Fuel Rail Pump – See Fuel Injection Pump . Parameter – A parameter is a value or a limit that is programmable.
This helps determine specific characteristics or behaviors of the engine. High Pressure Fuel Rail – See Fuel Manifold (Rail) . Injector Trim Codes – Injector trim 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 manufacturing of the electronic unit injector and for the life of the electronic unit injector. Password – A password is a group of numeric characters or a group of alphanumeric characters that is designed to restrict access to parameters.
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. Inlet Manifold Air Temperature/Boost Pressure Sensor – The inlet manifold air temperature/pressure sensor detects the air temperature and pressure 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. 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.
Pressure Limiting Valve (PLV) – The PLV is a valve in the fuel rail that prevents excessive pressure. The PLV will reduce the pressure to a safe level that will limit engine operation but the reduced pressure will not stop the engine. 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. 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.
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. 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. 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.
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 Trouble Codes for more information. NOx Reduction System – The 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. OEM – OEM is an abbreviation for the Original Equipment Manufacturer. This is the manufacturer of the machine or the vehicle that uses the engine.