9 Glossary
Aftertreatment Device (ATD)
An engine exhaust device that contains a DOC and a DPF along with several pressure and temperature sensors that work in conjunction to reduce particulate emissions from the engine.
Aftertreatment System (ATS)
A group of components that replace the traditional muffler and significantly reduce particulate emissions. The system consists of an ATD, FDV, Intake Throttle Valve, and Doser Block Assembly.
Ash
The unburnable solids that remain after soot regeneration. This is primarily composed of Calcium, Zinc, Sulfur, and Phosphrous (usually white to light gray in color).
Active Regeneration
A controlled re-action by the engine system to elevate the exhaust temperature to the point where soot can be oxidized.
Derate
A reduction in torque necessary to protect the engine and/or ATD from damage.
Diesel Oxidation Catalyst (DOC)
A flow through device located at the ATD inlet that enhances the oxidation of hydrocarbons in order to reduce particulate emissions.
Diesel Particulate Filter (DPF)
A device installed on a diesel engine system that captures and reduces particulate matter (PM) from the exhaust gas.
DOC Inlet Temperature Sensor
Measures exhaust gas temperatures entering the DOC.
DOC Outlet Temperature Sensor
Measures exhaust gas temperatures exiting the DOC.
Doser Block Assembly
Assembly that houses the Fuel Cutoff Valve (FCV), Fuel Compensation Pressure (FCP) Sensor, Electronic Dosing Valve (EDV), and the Fuel Line Pressure (FLP) Sensor.
Dosing Fuel Line
Line that carries fuel from the Doser Block Assembly to the FDV.
DPF Inlet Pressure Sensor
Measures exhaust gas pressures entering the DPF.
DPF Outlet Pressure Sensor
Measures exhaust gas pressures exiting the DPF.
DPF Outlet Temperature Sensor
Measures exhaust gas temperatures exiting the DPF.
Electronic Dosing Valve (EDV)
Pulse Width Modulation (PWM) controlled valve used to deliver the correct amount of fuel to the FDV in order to maintain the proper temperature across the DOC during regeneration.
Fuel Compensation Pressure (FCP) Sensor
Monitors fuel pressure into the Doser Block Assembly in order to properly deliver the correct amount of fuel delivered via the EDV.
Fuel Cutoff Valve (FCV)
Controls fuel flow into the Doser Block Assembly, is either On or Off.
Fuel Doser Valve (FDV)
Coolant cooled valve used to deliver fuel into the exhaust stream to maintain the proper temperature across the DOC during regeneration.
Fuel Line Pressure (FLP) Sensor
Pressure sensor used to diagnose abnormal conditions in fuel pressure after fuel exits the Doser Block Assembly.
High Box
A high speed high load condition.
Injection Nozzle
Part of the FDV; injects fuel into the exhaust stream to increase temperature for regeneration.
Intake Throttle Valve
Electronically controlled valve that will open or close in order to control a proper temperature at the face of the DOC during regeneration.
Low Box
A low speed low load condition.
Oxidation
A chemical reaction that uses heat to convert trapped particulate matter into a gaseous state and a remaining ash component.
Parked Regeneration
A manually initiated active regeneration that is performed on a parked vehicle.
Particulate Matter (PM)
Particles that are formed when diesel fuel is combusted. These particles (soot) are composed of sulfate particulates and Soluble Organic Fractions (SOF) that includes heavy hydrocarbons.
Passive Regeneration
Oxidation of trapped particulate matter in the ATD without the aid of active regeneration.
Soot
A dark powdery deposit of unburned fuel residues mainly composed of carbon.
Substrate
Core material used in diesel particulate filters that is made of ceramic or sintered metal.