Automotive Terminology, Codes, Abbreviations and Other Words That Can Be Just Plain Confusing

Most auto technicians and car parts people have a separate language which may not make any sense to the average person trying to work on their car. I am going to try to create a list of the most common terms and abbreviations to help you navigate through this world of car-speak. Some of these may seem self-explanatory but I don’t want to leave anything out that may be easily mistaken for something else.

So, what does ___ mean? :

4×2 = Four by Two, Only two of the drive wheels are powered at any time during driving

4×4 = Four by Four, All four of the drive wheels can be powered, controlled by the driver

ABS = Anti Lock Brakes, Prevents the wheels from locking up in extreme braking conditions

ASSY = Common shorthand for “Assembly”

AWD = All Wheel Drive, All four of the drive wheels are powered at all times

AWS = All Wheel Steering, only a few vehicles have ever been equipped with this option

BANK 1 = The side of the engine which contains Cylinder Number 1

BANK 2 = The side of the engine that does NOT contain cylinder number 1

CALIFORNIA EMISSIONS = A vehicle that has emission control systems that meet California’s strict emission standards.

CKP = Common shorthand for Crankshaft Position Sensor

CMP = Common shorthand for Camshaft Position Sensor

COUPE = A vehicle with two doors and a standard trunk

CYL = Common shorthand for Cylinder

DOHC = Dual Over Head Cam, The cylinder head(s) have two camshafts on top of each head.

DOWNSTREAM = The position of an oxygen sensor AFTER the catalytic converter

DPFE = This one can be tricky, many people disagree on what the “E” stands for. Usually, it is “Differential Pressure Feedback” and then the E is often “Electronic, Emission, Exhaust”. The DPFE measures the flow amount of the EGR valve on Ford vehicles

DRW = Common abbreviation for “Dual Rear Wheels”

ECT = Engine Coolant Temperature, used when referring to the sensor which measures the temperature of the engine

EFI = Electronic Fuel Injection

EGR = Exhaust Gas Recirculation, the EGR system recirculates exhaust fumes into the combustion chamber

EMISSIONS = Emissions on a vehicle are generally referred to as the pollutants which are released from a vehicle while running. Systems on every vehicle produced are specifically designed to reduce vehicle emissions.

ENG = Common Shorthand for Engine

ETC = Electronic Traction Control, System which prevents the front wheels from spinning under hard acceleration

FEDERAL EMISSIONS = The emission control system for all USA vehicles not originally sold in California, the other 49 states have less strict emission standards and therefore may have different components to control the emissions than California Emission vehicles

FGAW = Front Gross Axle Weight, The weight on the front axle of a vehicle when fully loaded

FLEX = Flex Fuel vehicle, the vehicle is designed to run on gasoline OR e85 Ethanol

FRT = Common Shorthand for “Front”

FWD = Front Wheel Drive, The two front wheels receive power from the engine to pull the car forward

GVWR = Gross Vehicle Weight Rating, The total weight of a vehicle when fully loaded (Maximum Weight)

HDW = Common shorthand for “Hardware”

IMRC = Intake Manifold Runner Control, A System which can open additional passages inside of the intake manifold to allow for more airflow when an engine reaches a certain RPM

LF = Left Front

LIMITED SLIP = A type of differential which causes both drive wheels to have power in low-traction situations, rather than allowing one to spin freely

LR = Left Rear

MAF = Mass Air Flow, a sensor which measures the amount of air entering the engine, the computer uses this information to help calculate how much fuel is needed

MPI = Multi-Port Injection, A type of fuel injection which has a separate injector for each of the cylinders

OE = Original Equipment

OEM = Original Equipment Manufacturer

OHC = Over Head Cam, The Camshaft is on top of the cylinder head instead of in the engine block

OHV = Overhead Valve (The Camshaft is in the engine block instead of the cylinder head)

RGAW = Rear Gross Axle Weight, the total weight on the rear axle of a fully-loaded vehicle

RF = Right Front

RPM =  Revolutions per minute, A way to keep track of how fast the engine’s crankshaft is rotating

RPO = Regular Production Option, A system of codes that General Motors vehicles use to track the options that a vehicle came with, an example is NP5 = Leather Wrapped Steering Wheel

RR = Right Rear

RWAL = Rear Wheel Anti Lock, Many Trucks are equipped with only rear ABS, this system prevents the rear wheels from locking under heavy braking

RWD = Rear Wheel Drive, The two rear tires receive the power from the engine to push the car forward

SEDAN = A four-door car with a trunk

SEFI = Sequential Electronic Fuel Injection

SRS = Safety Restraint System, which often refers to the airbag system of a vehicle

SRW = Single Rear Wheel (Used to identify the difference on heavy-duty trucks)

STD = Common Shorthand for “Standard”

TCS = Traction Control System

TPI = Tuned Port Injection

TPS = Throttle Position Sensor

UPSTREAM = The Position in the exhaust for an oxygen sensor, located BEFORE the catalytic converter

VTEC = A system used on Hondas, it means Variable Timing Electronic Control, it allows for two different camshaft profiles which  are controlled by the computer allowing the engine to run more efficiently

Disclaimer: We have attempted to make all information above as accurate as possible. We take no responsibility for any typos or incorrect information.

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