DTS Glossary of Terms

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Glossary Of Terms

Actuator
A device which delivers motion in response to an electrical signal.

Additive
A compound that enhances some property of, or imparts some new property to, the base fluid. In some hydraulic fluid formulations, the additive volume may constitute as much as 20 percent of the final composition. The more important types of additives include anti-oxidants, anti-wear additives, corrosion inhibitors, viscosity index improvers, and foam suppressants.

Aeration
The state of air being suspended in a liquid such as a lubricant or hydraulic fluid.

After cooler
A heat exchanger used to cool compressed induction air from turbocharging or supercharging. It reduces the charged air temperature by transferring heat from the charge air to a cooling medium such as air or coolant.

Ambient Temperature
The environmental air temperature in which something operates in. Typically it is a measurement of the air temperature in the shade with no solar radiation or wind.

Ampere - AMP
The standard unit for measuring the strength of an electrical current.

Analog
A continuously variable voltage.

APS - Accelerator Position Sensor
A potentiometer style sensor that indicates the operator's pedal position.

AWA Feature
A feature built into the high pressure oil rails used to dampen noises that can be caused by the hydraulic system.

BARO/BAP - Barometric Absolute Pressure Sensor
A variable capacitance sensor which when supplied with a 5 volt reference signal from the PCM, produced a linear analog voltage signal indicating atmospheric pressure.

BAT
Battery voltage.

Battery Saver
The battery saver feature is a computer controlled feature that automatically turns off interior lights and come accessories in a parked vehicle after a few minutes to prevent the battery from being drained such as when a door is left ajar.

BDC - Bottom Dead Center
The lowest position of a piston during the stroke.

Bio-Diesel
The mono alkyl esters of long chain fatty acids derived from renewable lipid feedstocks, such as vegetable oils and animal fats, for use in compression ignition (diesel) engines. Manufactured by transestrification of the organic feedstock by methanol.

Blow-by
The passage of unburned fuel and combustion gases past the piston rings of internal combustion engines, resulting in fuel dilution and contamination of the crankcase oil.

Boost Pressure
1- The pressure of the charge air leaving a turbocharger or supercharger.
2- Inlet manifold pressure that is greater than atmospheric pressure.

Brake Horsepower (bhp)
The power output from an engine, not the indicated horsepower. The power output of an engine, sometimes called flywheel horsepower is less than the indicated horsepower by the amount of friction horsepower consumed in the engine.

Brake Horsepower (bhp) Net
Net brake horsepower is measured with all engine components. The power of an engine when configured as a fully equipped engine.

BTU - British thermal unit.
The amount of heat required to raise the temperature of 1 pound of water 1 degree Fahrenheit.

Bypass Filtration
A system of filtration in which only a portion of the total flow of a circulating fluid system passes through a filter at any instant or in which a filter having its own circulating pump operates in parallel to the main flow.

Cackle
A noise above the normal sound of combustion that may sound like a rod knock, but is intermittent and increases in intensity as the engine warms up to operating temperature. This noise is may be caused by a pressure variation within the fuel rail causing incomplete fuel fill in a fuel injector on split-shot injectors. The cackle is usually attributed to cylinder #8.

CAC - Charge Air Cooling
A process of cooling the air coming from the turbocharger before it enters the engine.

Calibration
The data values used by the strategy to solve equations and make decisions. Calibration values are stored in Read Only Memory and put into the processor during programming to allow the engine to operate within certain parameters.

Camshaft
A shaft with eccentric lobes used in most internal combustion engines to open and close valves.

Canister Style Oil Filter
An oil filter that requires only the element be replaced and not the housing.

CAN
A communication protocol for data transfer between control modules.

Carbon Dioxide (CO2)
A colorless, odorless, non-toxic gas. It is one of main products of fossil-fuel combustion. Carbon dioxide is a greenhouse gas that contributes to the potential for global warming.

Carbon Monoxide (CO)
A colorless, odorless and toxic gas. It blocks the lungs’ ability to obtain oxygen. CO is produced by incomplete combustion of fossil fuels and is a major part of air pollution. Compression ignition (diesel) engines generate significantly lower CO emissions than spark ignited engines.

Catalyst
A substance that causes a chemical reaction without undergoing a chemical change itself.

Catalytic Converter
An anti-pollution device in the exhaust system that contains a catalyst for chemically converting some pollutants in the exhaust gasses into harmless compounds. (carbon monoxide, oxides of nitrogen and unburned hydrocarbons)

Cavitation
A dynamic condition in a fluid system that forms gas filled bubbles in the fluid.

Cavitation Erosion
A material-damaging process which occurs as a result of vaporous cavitation. "Cavitation" refers to the occurrence or formation of gas- or vapor- filled pockets in flowing liquids due to the hydrodynamic generation of low pressure (below atmospheric pressure). This damage results from the hammering action when cavitation bubbles implode in the flow stream. Ultra-high pressures caused by the collapse of the vapor bubbles produce deformation, material failure and, finally, erosion of the surfaces.

CCA - Cold Cranking Ampre Rating
A battery rating - The sustained constant current (in ampres) needed to produce a minimum terminal voltage under a load of 7.2 volts per battery after 30 seconds.

Cetane Number
A measure of ignition quality of diesel fuel. The higher the cetane number the easier the fuel ignites when injected into an engine. Cetane number is determined by an engine test using two reference fuel blends of known cetane numbers. The reference fuels are prepared by blending normal cetane (n-hexadecane), having a value of 100, with heptamethyl nonane, having a value of 15.

CKP Crankshaft Position Sensor
A magnetic pickup sensor that creates a sine wave voltage when the timing wheel on the crankshaft breaks its magnetic field. The CKP determines crankshaft position and speed.

Charge Air
Dense, pressurized, heated air discharged from a turbocharger or supercharger.

Closed Crankcase Breather
A ventilation system that recirculates crankcase vapors into the intake air system.

Closed Loop Operation
In a system that uses sensors to provide feedback to the PCM, the PCM uses the sensor to continuously monitor variables and adjust to match engine requirements.

Cloud Point
The temperature at which the paraffin in diesel fuel begins to form wax crystals making the fuel cloudy or hazy.

CMP - Camshaft Position Sensor
A magnetic pickup sensor that creates a sine wave voltage when a peg on the camshaft breaks its magnetic field. The CMP determines which cycle the piston is in (compression or exhaust).

Coefficient of Friction
The number obtained by dividing the friction force resisting motion between two bodies by the normal force pressing the bodies together.

Common Rail Injection
A diesel fuel injection system employing a common pressure accumulator, called the rail, which is mounted along the engine block. The rail is fed by a high pressure fuel pump. The injectors, which are fed from the common rail, are activated by solenoid valves. The solenoid valves and the fuel pump are electronically controlled. In the common rail injection system the injection pressure is independent from engine speed and load. Therefore, the injection parameters can be freely controlled. Usually a pilot injection is introduced, which allows for reductions in engine noise and NOx emissions.

Compression Ignition
The form of ignition that initiates combustion in a diesel engine. The rapid compression of air within the cylinders generates the heat required to ignite the fuel as it is injected.

Compression Ratio
In an internal combustion engine, the ratio of the volume of combustion space at bottom dead center to that at top dead center.

Continuous Monitor
A Powertrain Control module function that continuously monitors the inputs and outputs to ensure that readings are within set limits.

Controller Area Network - CAN
A J1939 high speed communication link. CAN-1 is a public drive train data link between the vehicle modules and the PCM. CAN-2 is a private link between the PCM and the FICM/IDM.

Coolant
A fluid used to remove and transfer heat.

Crankcase
The housing that encloses the crankshaft, connecting rods and pistons. Other parts may also be housed in the crankcase depending on engine configuration.

Crankcase Breather
A vent for the crankcase to release excess air pressure due to heat and combustion blowby.

Current
The flow of electrons flowing through a conductor. (AMPS)

Damper
A device that reduces the amplitude of torsional vibration.

Deaeration
The removal or purging of gases entrapped in coolant or engine oil.

Deaeration Tank / Degas Bottle
A separate tank in the cooling system used for one or more of the following functions:
1- Deaeration
2- Coolant reservoir (fluid expansion or afterboil)
3- Coolant retention
4- Filling
5- Fluid level indication

Digital Fuel Injection
A fuel injection system that uses both an open and close signal to control fuel injectors.

Diesel Particulate Filter (DPF)
An exhaust after treatment device that traps particulate matter, or soot, generated by the combustion process in diesel engines.

Displacement
The stroke of the piston multiplied by the area of the cylinder bore multiplied by the number of cylinders in the engine. (Cubic inch - CID or cubic centimeter - CC)

Drive-By-Wire
One or more of the primary vehicle systems operate with electronic controls instead of a traditional mechanical linkage. An electronic signal transmits driver input to steering, throttle or brake input to an electronically controlled steering gear, throttle body or brake system.

Driver
A transistor within an electronic module that controls power or ground to an actuator circuit.

Drivetrain Data Link (CAN 1) J1939
The primary communication link for the PCM, electronic system controller and instrument cluster.

DSB - Dispute Settlement Board
A committee that reviews customers' product performance and service complaints on vehicles.

Dual Timing System
A timing system that uses both a CKP and CMP sensors to determine engine speed and rotational position.

DVOM - Digital Volt Ohm Meter
A meter that uses a digital display to indicate a measured value. Preferred for use on microprocessor systems because a DVOM has a very high internal impedance and will not load down the circuit being measured.

ECM - Electronic Control Module
An ECM controls one or more of the electrical subsystems in a vehicle. It receives electronic signals and commands, processes them and controls electrical output devices via a preset program.

ECT - Engine Coolant Temperature Sensor
A thermistor style sensor used to indicate engine coolant temperature.

EGR Cooler
A device used to cool exhaust gases before they are returned to the intake air system.

EGRV - Exhaust Gas Recirculation Valve
A valve used to control the flow of exhaust gases into the intake manifold.

EGRP - Exhaust Gas Recirculation Valve Position Sensor
A potentiometer style sensor that indicates the amount of movement of the EGR valve.

EGRT Outlet
EGR cooler outlet temperature sensor which is used aid in controlling EGR valve position and throttle position. This is a two wire thermistor type sensor - it's internal thermistor forms a voltage divider with a pullup resister inside of the ECM.

EOT - Engine Oil Temperature
A thermistor type sensor that indicates engine temperature.

EP - Exhaust Pressure
The EP measures exhaust back pressure so that the ECM can control the EGR and turbocharger actuators. It is a three wire variable capacitance sensor. The ECM supplies a 5-volt reference signal which the EP sensor uses to produce a linear analog voltage to indicate pressure.

ESP - Extended Service Plan
A Ford Motor Company Extended warranty and service contract. These contracts are sold by Ford, Lincoln and Mercury dealers.

EVRT - Electronic Variable Response Turbocharger
The International Truck and Engine Corporation's trademark for its electronically-controlled turbo charger. Contains actuated vanes in the turbine housing that modify the flow characteristics of exhaust gasses through the turbine housing. The net benefit is the ability to provide the appropriate boost pressure for various engine speeds and load conditions. The EVRT lowers emissions and improves fuel economy. It also functions as a backpressure device which assists the EGR system and reduces engine warm up time.

FEAD (belt)
FEAD or Front End Accessory Drive Belt is the drive belt on the front of an engine that drives the accessory equipment like power steering pumps, alternators and A/C compressors. This is also commonly referred to as the "serpentine" belt.

FICM - Fuel Injection Control Module
An electronic unit which has the primary function of an electronic distributor for the injectors. It also is the power supply for the injectors.

FRP Fuel Rail Pressure
The FRP provides a feedback signal to the ECM indicating the fuel pressure at the fuel rail. It is a three wire variable capacitance sensor. The ECM supplies a 5-volt reference signal which the EP sensor uses to produce a linear analog voltage to indicate pressure.

FTS Fuel Temperature Sensor
The FTS measures fuel temperature at the fuel rail and changes resistance according to changes in temperature. This is a two wire thermistor type sensor - it's internal thermistor forms a voltage divider with a pullup resister inside of the ECM. When the temperature of the fuel decreases, the resistance of the thermistor increases and the signal voltage increases. When the temperature of the fuel increases, the resistance of the thermistor decreases and the signal voltage decreases.

Gage
An instrument or device for measuring, indicating or comparing a physical characteristic.

Glow Plug Sleeves
Stainless steel sleeves used to protect the glow plugs from coolant.

GPCM - Glow Plug Control Module
Module which supplies power to the glow plugs and identifies variation in current flow to the glow plugs.

Hall Effect Sensor
A hall effect sensor generates a digital on/off signal that indicates engine speed and timing. The signal is created by a switching action caused by the passing of a vane though a positive and negative voltage potential. When the vane is between the potential, a signal is created. When the gap in between the potential is open, no signal is generated. The wider the vane the longer the duty cycle and the shorter the vane the shorter the duty cycle. A single shorter or longer vane can be used to identify position.

Heat Exchanger
A device which transfers heat through a conducting wall from one fluid to another or from a fluid to air. Examples include radiators, condenser cores, oil coolers, after coolers.

Heat Rejection
The process of heat transfer to the engine coolant.

HFCM - Horizontal Fuel Conditioning Module
A frame mounted fuel conditioning module that contains an electric fuel pump, primary fuel filter and water separator with a water sensor.

HPFP (High Pressure Fuel Pump)
A fuel pump that creates and maintains a high pressure fuel supply used on a common rail fuel injection system.

Hydrocarbons - Hc
Compounds containing only carbon and hydrogen. Petroleum consists chiefly of hydrocarbons.

Hydraulic/Electronic Unit Injector (HEUI)
A type of unit injector actuated by engine oil pressure rather than the camshaft. A very high oil pressure (up to 3,000 psi) is created by a separate oil pump. This high pressure is routed to every injector through a gallery. The engine’s Electronic Control Module varies the pressure in response to engine speed and other parameters.

Hydrometer
An instrument for determining either the specific gravity of a liquid or the API gravity.

IAT - Intake Air Temperature Sensor
A thermistor style sensor used to indicate air temperature before the charge air cooler.

IAT2 - Intake Air Temperature 2 Sensor
A thermistor style sensor used to indicate air temperature - after passing through the charge air cooler.

In-line Filter
A filter assembly in which the inlet, outlet and filter element axes are in a straight line.

ICP- Injection Control Pressure
A variable capacitance style sensor used to indicate high pressure oil system pressure.

IDM - Injector Drive Module
An electric unit which has a primary function of an electronic distributor for the injectors. It also is the power supply for the injectors. It supplies 90 volts at 7 amps to the injectors.

Impedance
A form of opposition to AC current flow measured in Ohms.

Inhibitor
Any substance that slows or prevents such chemical reactions as corrosion or oxidation.

I/0 Injector Test
A test that can be performed using the WDS to disable one injector at a time while watching Mfdes to determine a weak contributing injector.

IPR - Injection Pressure Regulator
Controls injection oil pressure. An electrical signal to a solenoid creates a magnetic field which applies a variable force on a poppet to control pressure. The quantity of fuel delivered to the combustion chamber is proportional to injection control pressure.

IVS - Idle Validation Switch
An on/off switch that indicates when the accelerator pedal is in the idle position.

There are no terms that start with this letter.

Key PWR
Battery voltage that is received indicating that the ignition switch is in the ON position.

KOEO - Key On Engine Off Self Test
A self-test operation that is performed with the ignition switch in the ON position with the engine OFF.

KOER - Key On Engine Running Self Test
A self-test operation that is performed with the ignition switch in the ON position and the engine RUNNING.

Long Life Ethylene Glycol Coolant
A premium coolant, with an Ethylene Glycol base, that can be used in a cooling system for an extended time without needing to be changed. Long life coolants do not require the use of extenders. Long life coolants can be identified by its yellow color.

Lubricant
Any substance interposed between two surfaces in relative motion for the purpose of reducing the friction and/or the wear between them.

Lubricity
The ability of an oil, fluid or grease to lubricate; also called film strength.

Main Power Relays
(Two) Battery power relay switches for the PCM and FICM (modules) that are key power initiated and controlled by the corresponding powered module.

MAP - Manifold Absolute Pressure Sensor
A MAP sensor generates a digital frequency that indicates manifold boost pressure above atmospheric pressure. The signal is created by switching action caused by manifold pressure of a diaphragm connected to a capacitor circuit in the sensor. The digital frequency increases as pressure increases. A MAP sensor has three connection: signal return(gnd), MAP signal, and VREF.

Misfire Detection
Uses engine RPM changes during a firing cycle to determine a low contributing cylinder.

Modular Water Pump
Is a water pump that uses the front cover as a housing and only the hub and impeller are replaceable.

Normally Closed
Refers to a switch or a solenoid that is closed when no control or force is acting on it.

Normally Open
Refers to a switch or a solenoid that is open when no control or force is acting on it.

Nitrogen Oxides (NOx)
Several air-polluting gases composed of nitrogen and oxygen which play an important role in the formation of photochemical smog. Nitrogen oxides are collectively referred to as ”NOx”, where ”x” represents a changing proportion of oxygen to nitrogen. Internal combustion engines are significant contributors to the worldwide nitrogen oxide emissions. For the purpose of emission regulations, NOx is composed of colorless nitric oxide (NO), and the reddish-brown, very toxic and reactive nitrogen dioxide (NO2). Other nitrogen oxides, such as nitrous oxide N2O (the anesthetic ”laughing gas”), are not regulated emissions.

OASIS - Online Automotive Information System.
A computer system that provides vehicle, warranty, recall,and ESP information about specific vehicles. OASIS is accessible by authorized Ford and Ford dealer employees using computer terminals at the dealership and at Ford Motor Company.

On-Board Diagnostics (OBD)
A system on board of the vehicle that monitors emission control components and alerts the driver (e.g., by a dashboard light) if malfunctions or emission deterioration occurs. The OBD system involves a number of sensors and a data processor, which is typically integrated with the vehicle’s electronic management system.

Particulate Matter (PM)
Particles formed by incomplete combustion of fuel. Compression ignition (diesel) engines generate significantly higher PM emissions than spark ignited engines. The particles are composed of elemental carbon, heavy hydrocarbons (SOF), and hydrated sulfuric acid (’sulfate particulates”).

PATS - Passive Anti-Theft System
A vehicle security system that prevents engine operation if a theft attempt is detected. It protects against theft by requiring a specially coded ignition key that transmits a unique code to the vehicles computers. The vehicle starts and operates only with the key that matches the key code programed to the vehicle.

PCM - Powertrain Control Module
The housing that contains the micro computer, VREF regulator, input conditioners and output drivers.

PCV - Pressure Control Valve
A fuel control valve permanently attached to the high pressure fuel pump in a 6.4L PSD engine. The PCV governs the fuel pressure that is delivered to the fuel injectors and acts as a dampening device for the fluctuations in pressure that occur during fuel delivery through the pump and the injection process.

POT - Potentiometer
Converts a mechanical motion to a voltage value. Most often used to sense the position of a component. This sensor works as a variable voltage divider. The wiper arm is mechanically connected to the component desired to be sensed. Potentiometers have three connections: VREF, signal out, and ground.

Pour Point
A measure of the ability of a diesel fuel to operate under cold weather conditions. Defined as the temperature at which the amount of wax out of solution is sufficient to gel the fuel when tested under standard conditions (ASTM D97).

Pre combustion Chamber
A small, auxiliary combustion chamber connected by a narrow orifice with the main chamber. Fuel is injected into the pre chamber and ignites there, causing hot gases to expand into the main chamber (cylinder).

Pulse Width
The length of time an actuator, such as an injector, remains energized.

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Relative Compression Test
A test that can be run with the WDS to measure compression of a cylinder relative to the other cylinders in the engine. This test is accomplished by comparing the rpm of the engine during each compression stroke.

Regeneration
As related to diesel particulate filters, regeneration is the process of burning off accumulated soot that is trapped and stores. This process restores efficiency of the filter.

Rocker Arm Carrier
A housing that the rocker arms and their fulcrums are mounted to.

Split Shot Injector
Split Shot Injectors provide improved exhaust emissions and quiets engine operation by tailoring the injection of fuel, without a decrease in performance.

Stiction
Stiction is a new term based on the blending of "static friction" perhaps also influenced by the verb "stick." Two solid objects pressing against each other (but not sliding) will require some threshold of force parallel to the surface of contact in order to overcome static cohesion. Stiction is a threshold, not a continuous force. As applied to our profession, the spool valves in certain fuel injectors can stick due to the viscosity of the engine oil coating them. This can cause a spool valve to stick or operate in a delayed or slow motion causing driveability issues.

Thermistor
Sensor used to determine temperature. A thermistor changes it's resistance value in relation to temperature change. Increasing temperature results in decreasing resistance, decreasing temperature results in increasing resistance. The thermistor in conjunction with a current limiting resistor in the PCM forms a voltage divider that provides a voltage signal indicating temperature. Since the top half of the voltage divider is the current limiting resistor and is internal to the PCM, a thermistor sensor only has two connections, signal return and ground.

TPMS (Tire Pressure Monitoring System)
A tire pressure monitoring system (TPMS) is an electronic system to monitor the air pressure inside a pneumatic tire. They are sometimes referred to as remote tire pressure monitoring systems (RTPMS) or simply as run flat indicators. This system is required on all light motor vehicles under 10,000 lbs sold after September 1, 2007. For more information Google "TREAD Act."

Turbo charging
A process of compressing the engine intake air charge in order to allow more air and fuel into the cylinder and, thus, to increase the engine power output. The compressor, called the turbo charger, is driven by an exhaust gas propelled turbine.

Turbo Lag
The time delay between injecting fuel to accelerate and delivering air to the intake manifold by the turbocharger. This phenomenon may cause black smoke emissions in some turbocharged diesel engines during acceleration.

There are no terms that start with this letter.

Variable Capacitance Sensor
A sensor that is used to determine pressure. A variable capacitance sensor changes it capacitance value in relation to pressure change. Increasing pressure results in a lower capacitance, thus increasing return voltage. Decreasing pressure results in a higher capacitance and a lower voltage. Variable capacitance sensors are 3 wire sensors.

VCV - Volume Control Valve
A control valve permanently attached to the high pressure fuel pump in a 6.4L PSD engine. The VCV regulates the delivery of fuel from the internal transfer pump to the high pressure pumping elements and adjusts the low pressure side of the system to match the needs of the engine thus increasing efficiency.

VGT - Variable Geometry Turbocharger
A turbocharger that has a turbine housing that can change sizes through electronically controlled hydraulics.

VGTCV - Variable Geometry Turbocharger Control Valve
Could also be called EVRTCV. Controls oil flow in and out of the VGT actuator in order to change the effective size of its turbine housing.

VPWR
Battery voltage.

VREF
5 volt reference voltage generated by the PCM.

VSS - Vehicle Speed Sensor
Normally a magnetic pickup style sensor that is mounted on the tailshaft of the transmission to indicate ground speed.

Wastegate
A device used on turbochargers to limit boost production by bleeding exhaust gasses and pressure to slow the turbine and compressor wheels. It can allow increased boost pressures in the air charging system at low speeds while not hindering top end performance.

There are no terms that start with this letter.