Dictionary of Automotive Terms Abbreviations

DICTIONARY OF AUTOMOTIVE TERMS - "Ac"

A/C

Across Corners

An abbreviation for across corners which indicates the distance on a nut or bolt head from one corner to the opposite corner rather than the distance from one flat surface (A/F) to the opposite (which would be the size of wrench needed to install or remove the nut or bolt). The purpose of the (A/C) dimension is to know how large a hole might be needed to insert a recessed nut or bolt head.
Acronym for Alternating current.
Acronym for air conditioning or Air conditioner.
Symbol for actinium
The transformation temperature on heating of the phase changes of iron or steel, subscripts indicating the designated change, e.g., Ac₁ is the eutectoid (723°C) and Ac₃ the ferrite/austenite phase boundary.
Acronym for Asphaltic concrete. A mixture of asphalt cement, graded aggregate, mineral filler, and additives.

AC: A vehicle brand of which the 1925-48 models are Classic cars.

AC Ace: 1956 AC Ace

A vehicle brand of which the 1954-61 Ace models are Milestone cars.

AC Aceca: AC Aceca

(pronounced ah-SEEK-uh) A vehicle brand of which the 1955-61 Aceca models are Milestone cars.

ACAP: Acronym for Associação do comércio automovóvel de Portugal

AC balancer: An arrangement of transformers used to equalize the voltages between the wires of a multiple-wire system.

AC Buckland: AC Buckland

A vehicle brand of which the 1949 Buckland Open Tourer is a Milestone car.

Acc: Abbreviation for Accessories.

ACC

Acronym for Automatic Cruise Control.
A term found on a Cruise control switch which indicates the direction the switch needs to be moved to increase the speed (accelerate) of the vehicle.
Acronym for Air Conditioning Clutch
Acronym for Automatic Climate Control

ACCC: Acronym for Air conditioner clutch compressor signal

Accelerate

To increase the speed of a vehicle. Opposite of Decelerate.
To speed up the chemical reaction or curing process of an Adhesive. For example, you can speed up the drying time of an adhesive or sealer by increasing the temperature or by adding a chemical curing agent, or accelerator, to a base compound.

Accelerating machine: See
Accelerator

Accelerating-well ports: These ports or passageways in the Carburetor prevent momentary leanness during the period that occurs between the opening of the air valve and the actual discharge of fuel from the secondary nozzles.

Acceleration: The rate of change of velocity or Speed. Velocity is steady and is measured in distance per time (e.g., feet per second, miles per hour, kilometers per hour). Acceleration keeps increasing and is measured in velocity per time (e.g., feet (or meters) per second per second or feet (or meters) per second squared). It is a vector quantity and has both magnitude and direction. It may be positive or negative depending upon whether the object is speeding up or slowing down. The latter is often called Deceleration.
Also See
Lateral acceleration
Sluggish acceleration
Yaw acceleration

Acceleration enrichment: The action of increasing the fuel/air mixture during acceleration in order to improve the vehicle's speed and its smooth response.

Acceleration pump: See
Auxiliary acceleration pump

Acceleration Sensor: See
Lateral Acceleration Sensor

Acceleration slip regulation: (ASR) The Bosch term for traction control.

Acceleration stress: The influence of acceleration (or deceleration) on certain physiological parameters of the human body. The degree of tolerance depends on the magnitude and duration of the acceleration as well as the direction of the force against his body.

Acceleration Switch: See
Lateral Acceleration Switch

Acceleration tolerance: The maximum acceleration force that a person can withstand before blacking out or otherwise losing control.

Accelerator

Click to supersize image

In automobiles, this is the gas pedal which is attached by Linkage to the Throttle in the Carburetor or to the Fuel injection system. It regulates the amount of fuel which is sent to the engine. In Motorcycles, the accelerator is located on the right-hand twist grip or an actuating lever. Also called throttle linkage.

Also See
Depress the accelerator
Ease up on the accelerator
Step on the accelerator
Take foot off the accelerator
A chemical which is added to something to make a process happen more quickly. For example, a chemical may be added to paint to cause it to dry faster. The opposite is retarder. A material added to an adhesive to speed up its cure or to chemically convert the whole mass to a solid. Accelerators differ from Catalysts in that they are a part of the chemical reaction and lose their chemical identity as a result.
Any substance increasing the speed of the vulcanization process of rubber.

Accelerator interlock: A connection between the gas pedal and the automatic transmission.

Accelerator pedal: The Accelerator, Gas pedal, or Throttle pedal.

Accelerator pump: A small cylinder and piston usually located inside the Carburetor that sprays an extra amount of fuel into the engine during Acceleration. It improves acceleration by giving more boost and reducing a momentary lag in power. It is actuated by depressing the pedal.

Accelerometer: An instrument which measures the amount of Acceleration in a specific direction.

Acceptable quality level: (AQL) A manufactured good that may not be perfect but does reach a level of shape, size, and performance, etc. that will make it work and last as long as the manufacturer expects.

Acceptance test: An examination of a part or its assembly to determine if it meets a prescribed standard.

Access: A way of reaching something that is usually hidden or covered.
Also See
Access panel

Access Cab: A type of pickup truck (by Toyota) which has a second row of seating; but unlike a Crew cab (which has four full size doors) it has a half-door that can be opened only after the main door is opened. The seating is usually a little more cramped than in a Crew cab. Also called Club Cab, Extended Cab, King Cab, Xtracab, Supercab, or Cab Plus by other manufacturers
Also See
Easy Access Cab

Access hole: An opening through which you can reach something. It is usually covered with a Panel.

Accessible: See
Readily Accessible
Reasonably Accessible

Accessible hermetic: Assembly of motor and compressor inside a single bolted housing unit.

Accessories: Items and packages of equipment which are beyond the standard equipment supplied in a new vehicle.

Accessory: See
Accessories

Accessory gearbox: A transmission, driven remotely from the main engine, to which other items (e.g., generator, pumps) are mounted.

Accessory package: A set of features or appointments which may be ordered at extra cost on a new vehicle.

Access panel: The Cover which conceals the engine on a Mid-engine vehicle. Also called Engine cover.
Also See
Hood

Access road: A temporary or permanent road over which timber is transported from a loading site to a public road. Also called a haul road

Access slots: Openings in the brake backing plates or brake drums that allow you to reach the Star-wheel adjusters

Accident: See
Car accident

Accident damage: The destruction caused to a vehicle's bodywork when it is involved in an accident.

AC circuit: A circuit which passes only alternating current as opposed to direct current, e.g., it may have a capacitor in series, which blocks direct current.

AC commutator motor: An AC motor which has a commutator as an essential part of its construction.

Accord: Click image for books on
Honda Accord

A model of automobile manufactured by Honda.

ACCS: Acronym for A/C Cycling Clutch Switch

Accumulator

A storage battery for an electric car.
A part of a hydraulic system filled with nitrogen gas and used to store high pressure fluid to provide pressure assistance for system operation.
A pressurized container for an automatic leveling suspension system.
A part of the hydraulic system which is charged by the fluid pump, absorbs fluctuating fluid delivery, stores fluid at pressure, and can provide a rapid flow of fluid under pressure.
A device in the fuel line between the pump and filter that keep up the fuel pressure when the fuel pump is off thus preventing vapor lock and excessive fuel pump noise in having to build up pressure when needed
A vessel that stores hydraulic fluid under pressure.
A storage tank which receives liquid refrigerant from the evaporator and prevents it from flowing into the suction line before vaporizing.
A refrigerant storage device used on General Motors and Ford systems that receives vapor and liquid refrigerant from the evaporator. The accumulator, which contains Desiccant, performs a function similar to that of a receiver-drier it separates liquid from the vapor, retains the liquid and releases the vapor to the compressor. Always located on the low side of the system.

Also See
Accumulator piston
Fuel accumulator
Hydraulic accumulator
Pressure accumulator

Accumulator battery: A storage battery (i.e., the main battery in your vehicle).

Accumulator box: A vessel usually made of plastic which contains the plates and electrolyte of an accumulator.

Accumulator drier: A device which is part of the air conditioning system. It is made up of a tank, filter, drying agent, and a vapor return tube. It is usually found on the evaporator outlet. It stores the excess refrigerant and removes the moisture from the refrigerant (thus the name drier).
Also See
Receiver-drier

Accumulator grid: The lead grid which forms one of the plates of a lead-acid accumulator having pasted plates.

Accumulator piston: A unit found in the Automatic transmission to assist the Servo to apply the Brake band quickly and smoothly.

Accumulator system: In an automatic transmission, it includes a hydraulic Accumulator piston which is controlled by a valve.

Accumulator traction: See
Battery traction

Accumulator valve: A device which operates the hydraulic Accumulator piston in an automatic transmission.

Accumulator vehicle: See
Battery traction

AC Current: See
Sine Wave AC Current

AC current sine wave: Wave form of single frequency alternating current; wave whose displacement is sine of angle proportional to time or distance.

ACD: Acronym for Air Conditioning Demand Switch

Ace: An American trucker's colloquial term for someone with a class A license.
Also see
AC Ace

ACEA: Acronym for Association des Constructeurs européens d'Automobiles (i.e., European Automobile Manufacturers' Association).

Aceca: See
AC Aceca

Acetate: Also see
Calcium magnesium acetate Magnesium acetate

Acetone: A fast drying solvent used in some rapid drying adhesives, such as nitrile rubber, or vinyl resin-based types

Acetylene: A gas composed of two parts of carbon and two parts of hydrogen. When burned in an atmosphere of oxygen, it produces one of the highest flame temperatures obtainable for welding.
Also See
Oxygen acetylene cutting

Acetylene bottle: See
Acetylene cylinder

Acetylene cutting: See
Oxygen acetylene cutting

Acetylene cylinder: Acetylene Cylinder

A specially built container manufactured according to I.C.C. Standards. Used to store and ship acetylene. Also called acetylene tank or acetylene bottle

Acetylene hose: A flexible medium used to carry gases from regulators to the torch. It is made of fabric and rubber.

Acetylene regulator: An automatic valve used to reduce acetylene cylinder pressures to torch pressures and to keep the pressures constant.

Acetylene tank: See
Acetylene cylinder.

AC generator

AC Generator

An electromagnetic generator for producing alternating EMF and delivering AC to an outside circuit.
A generator produces direct current (DC) while an alternator produces alternating current (AC). Because alternators were introduced to automobile electrical systems after generators had been in use for some time, some people referred to the new alternator as AC generator.

Ache: See
Headache rack

Ache rack: See
Headache rack

Acid: See
Battery acid
Chromic acid
Oxalic acid

Acid deposition: After acid compounds are sent into the atmosphere (e.g., through a smokestack), it returns to the surface mixed with the rain.
Also see
Acid rain.

Acid Fuel Cell: See
Phosphoric Acid Fuel Cell

Acidity: The presence of acid-type constituents whose concentration is usually defined in terms of Neutralization number. The constituents vary in nature and may or may not markedly influence the behavior of the oil.

Acid mine drainage: Water pollution that results when sulfur-bearing minerals associated with coal are exposed to air and water and form sulfuric acid and ferrous sulfate. The ferrous sulfate can further react to form ferric hydroxide, or yellowboy, a yellow-orange iron precipitate found in streams and rivers polluted by acid mine drainage.

Acid precipitation: See
Acid rain

Acid process: A way of making steel where the iron has a low level of phosphorous and the furnace is lined with silicon.
Also See
Basic process

Acid rain

When the smoke created by factories and vehicle exhausts is taken by the wind and joined with rain clouds, the mixture is often acidic. As a result the rain that falls to the ground (and even on your car) may damage whatever it strikes.
A form of wet deposition in which acid molecules or particles in the atmosphere are returned to the surface having been washed out by rain or snow as it falls. The unnatural acidity (pH 3-5.5) is caused mainly by the oxides of sulfur and nitrogen from the burning of coal and oil.
Precipitation containing harmful amounts of nitric and sulfuric acids formed primarily by sulfur dioxide and nitrogen oxides released into the atmosphere when fossil fuels are burned. It can be wet precipitation (rain, snow, or fog) or dry precipitation (absorbed gaseous and particulate matter, aerosol particles or dust). Acid rain has a pH below 5.6. Normal rain has a pH of about 5.6, which is slightly acidic. The term pH is a measure of acidity or alkalinity and ranges from 0 to 14. A pH measurement of 7 is regarded as neutral. Measurements below 7 indicate increased acidity, while those above indicate increased alkalinity. Also called acid precipitation or acid deposition

Acid Rechargable Battery: See
Lead Acid Rechargeable Battery

Acid Tester: See
Battery Acid Tester

AC Ignition System: See
Continuous AC Ignition System

Ackermann: See
Ackermann steering

Ackermann steering

Ackermann Steering

A double-pivoting steering system where the outer ends of the Steering arms are bent slightly inward so that when the vehicle is making a turn, the inside wheel will turn more sharply than the outer wheel. This is done to compensate for the greater distance the outside wheel must travel. Notice 20 degrees on left wheel and 30 degrees on right wheel
Arrangement whereby a line extended from the track-arms, when the wheels are set straight ahead, should meet on the chassis centerline at 2/3 of the wheelbase from the front, allowing the inner stub-axle to move through a greater angle than the outer.

Ackermann angle: The toe-out or toe-in of a vehicle with Ackermann steering when the wheels are positioned straight ahead.

Ackermann axle: In a vehicle with Ackermann steering (at the front of the vehicle), it is a non-rotating axle that is steerable and has two pivot points (one on each end of the axle) with vertical Kingpins.

ACL BI-MET: Acronym for Air cleaner bi-metal sensor.

ACL DV: Acronym for Air cleaner duct and valve vacuum motor.

AC motor: An electric motor which operates from a single or polyphase alternating current supply.

Also See
Capacitor motor
Induction motor
Synchronous motor

ACON: Acronym for Air Conditioning On Signal

Acorn Die: A form of threading die for use in screw machines. The cutting portion resembles an acorn.

Acorn Nut: A blind tapped hex nut with an acorn shaped top. Provides sealing for projecting threaded parts.

Acoustic amplifier: A device or system that increases mechanical vibrations

Acoustics

The science of sound waves including production and propagation properties.
The characteristics of the interior of a car which determine the quality of sound transmission inside.

Also see
Architectural acoustics
Atmospheric acoustics

ACP: Acronym for Air Conditioning Pressure Signal

ACPSW: Acronym for Air Conditioning Pressure Switch

Acquisition fee: A charge for processing a vehicle lease and is probably not negotiable. On a shorter term lease, the acquisition fee can have a large impact on the cost of the lease.

ACR: Acronym for Air Conditioning Relay

ACR4: Acronym for Air Conditioning Refrigerant, Recovery, Recycling, Recharging

ACRS: Acronym for Air Cushion Restraint System

Across corners: Across Corners

(A/C) The distance on a nut (for instance) from one corner to the opposite corner rather than the distance from one flat surface (A/F) to the opposite (which would be the size of wrench needed to install or remove the nut). The purpose of the A/C dimension is to know how large a hole might be needed to insert a recessed nut.

Across flats: Across Flats

(A/F) The distance on a nut (for instance) from one flat surface to the opposite flat surface, i.e., this is the size of the wrench needed to install or remove the nut.
Also See
Across corners.

ACR tubing: Tubing used in air conditioners and refrigerators. The ends are sealed to keep tubing clean and dry.

Acrylate: A polymer used to strengthen rubber (e.g., Ethyl acrylate).

Acrylic: A term relating to a type of paint made by polymerizing acrylonitrile.

Acrylic fibers: Continuous long filaments or fibers from linear polymers.

Acrylic finish: A final coating of paint which uses Acrylic paint, often where the pigment and an acrylic paint are mixed together.
Also See
Two-pack paint.

Acrylic paint: A type of paint made by polymerizing acrylonitrile.

Acrylic resin: A thermoplastic synthetic polymer made by polymerizing an acrylic derivative such as acrylonitrile, acrylic acid, ethyl acrylate, and methacrylate. It is used for adhesives, protective coatings, and paint finishes.

ACS

Acronym for Active control system
Acronym for Air conditioning system
Acronym for attitude control system

AC Shelby Cobra: AC Shelby Cobra

A vehicle brand of which the 1962-67 Shelby Cobra models are Milestone cars.

ACT

Acronym for Air charge temperature.
Acronym for active control technology

Acting: See
Double-acting
Dual-acting
Single-acting

Action: See
Capillary Action
Caster action
Galvanic Action
Mist Action
Oscillating action
Parallel action locking pliers
Reciprocating action
Self-energizing Action
Servo Action

Action brakes: See
Servo action brakes

Action locking: See
Parallel action locking pliers

Action locking pliers: See
Parallel action locking pliers

Activate: To change an adhesive film from a dry or inactive state to a useful, sticky state.

Activated: See
Cable activated

Activated alumina: Chemical which is a form of aluminum oxide. It is used as a drier or desiccant

Activated carbon: A very porous carbon that is used to strain liquid leaving behind impurities on the carbon and the pure substance going through it

Activated carbon canister: An automotive filter in which Activated carbon has been placed so that gas tank fuel vapors, which have accumulated when the vehicle is not running, are trapped in the filter. When the engine is running, hot air is forced into the filter and push out the vapors into the engine. In this way, pollution is reduced and conservation of the fuel is maintained. Also called activated charcoal trap or charcoal canister.

Activated charcoal: Charcoal treated with acid to increase its adsorptive power
Also See
Activated carbon
Charcoal

Activated charcoal trap: See
Activated carbon canister

Activating agent: A substance which is used to speed up the process of curing a tire. Also called an Activator

Activator: A substance which is used to speed up the process of curing a tire. Also called activating agent.

Activation: See
Chemical Activation
Electrical Activation

Activation polarization: Activation polarization is present when the rate of electrochemical reaction at an electrode surface is controlled by sluggish electrode kinetics. This is similar to chemical reactions where the reacting species must overcome an activation barrier. For Fuel cells, this region is characterized by a drop from the theoretical EMF or ideal voltage prior to electron or ion flow.

Activators: See
Vacuum Activators

Active Area cell: The surface area of an individual Fuel cell that is available for chemical reaction. The active area is typically less than the total area of a cell to accommodate cooling, distribution, and sealing mechanisms.

Active braking time: The length of time (excluding the driver's reaction time) a vehicle takes to come to a complete stop after the brakes are applied.

Active control system: (ACS) A flight control system designed to improve the performance and behavior of an airplane.

Active Gases: See
Radiatively Active Gases

Active material: In a storage battery, the brown peroxide of lead of the positive plates and the gray metallic lead of the negative plates upon which the sulfuric acid acts.

Active noise control system: See
Anti-noise system

Active power: The component of electric power that performs work, typically measured in kilowatts (kW) or megawatts (MW). Also known as Real power.
Also see
Apparent Power
Reactive Power

Active safety: The opposite of passive safety. Passive safety involves Seat belts, Airbags, Bumpers, etc. so that in the event of an accident the passengers are protected. Active safety involves factors which will assist the Driver in avoiding an accident. They include brakes, steering, handling response, Acceleration, etc.

Active solar: Energy from the sun collected and stored using mechanical pumps or fans to circulate heat-laden fluids or air between solar collectors and a building or vehicle.

Active suspension: While conventional Suspension uses springs and Shock absorbers to isolate the vehicle from the bouncing movement of the wheels when it contacts rough roads, active suspension uses power actuators which are controlled by a Computer. These actuators place the wheels of the vehicle in the best position to accommodate rough roads as well as compensate for different load Levels.

Activities: See
Kaizen Activities

Activity: See
Catalytic Activity
Low Temperature Activity
Specific Activity
Temperature Activity

Activity factor: See
Blade activity factor

AC transformer: An electromagnetic device which alters the voltage and current of an alternating current supply in inverse ratio to one another. It has no moving parts and is very efficient.

ACTS: Acronym for Air charge temperature sensor.

Actual cash value: (ACV) The amount of money a dealer has invested in the purchase of a used vehicle plus any additional costs to repair the unit in order to get it ready for resale.

Actuate: The action of bringing something into operation.

Actuating lever: A triggering device used to bring something into operation.

Actuating switch: A triggering device used to bring something into operation.

Actuating system: The parts of a brake system that transmit the braking force applied at the brake pedal to the wheel friction assemblies and increase it to a usable level.

Actuation: See
Valve Actuation
Variable valve actuation

Actuation Distance: See
Brake System Actuation Distance

Actuation Time: See
Brake System Actuation Time

Actuator

A device which controls or operates another device.
A regulating valve which converts a form of energy into mechanical motion to open or close the valve seats
A device which responds to an output signal from a computer.
The portion of a regulating valve which converts mechanical fluid, thermal energy, or electrical energy into mechanical motion to open or close the valve seats

Also See
Brake Actuator
Electrohydraulic Actuator
Feedback Carburetor Actuator
Hydraulic Actuator
Idle Speed Actuator
Spring Type Brake Actuator

Actuator arm: A linkage connecting the diaphragm to the contact breaker platform in an advance mechanism of a distributor. Also called diaphragm link.

Acura

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Acura

An upscale series of vehicles from the Honda manufacturers. It includes the following:

CL (1997-2003)
Integra (1988-2001)
Legend (1988-95)
MDX (2001-07)
NSX (1991-2005)
RDX (2007-2009)
RL (1996-2008)
RSX (2002-06)
SLX (1996-99)
TL (1995-2008)
TSX (2004-08)
Vigor (1992-94)

ACV

Acronym for Actual cash value
Acronym for Air control valve
Acronym for air cushion vehicle (i.e., hovercraft).