BAR Smog Check Glossary
Introduction
Any specialized area of knowledge has its own jargon, words and acronyms that have obscure or
specialized definitions within that knowledge area.
The California Bureau of Automotive Repair's Smog Check Program is no exception. This
glossary is intended to assist you in understanding those specific and technical meanings.
Air Injection System (AIS)
Pumps air into the exhaust manifold to burn unburned fuels (Hydrocarbons and Carbon
Monoxide) and helps to warm up the catalytic converter. There are several types of systems
used: an air pump design which uses an electric pump, a mechanical pump driven by the engine,
or a pulse air design which uses exhaust pulses to draw air into the exhaust.
Also known as the Smog Pump.
ARB / CARB (California Air Resources Board)
A government agency that oversees the air quality and establishes the Rules and Regulations to
maintain healthy air quality. Typically referred to simply as ARB.
ASM (Acceleration Simulation Mode)
The test type for vehicles operated on a dynamometer (treadmill like device) which simulates
actual driving conditions. The vehicle is tested at 15 mph with a 50% load and at 25 mph with a
15% load on the engine.
AVE (Average Emissions)
The average passing emissions for vehicles in the same Emissions Standards Category (ESC).
ESCs are based on model year and whether the vehicle is a passenger car or a light-, medium-,
or heavy-duty truck. The average passing emissions reading is meant as a guidepost for
inspectors when repairing vehicles that fail a Smog Check; it has no effect on the pass/fail result
of the emissions test.
Basic Area
An area less polluted than an enhanced area requiring only Two Speed Idle Smog testing for
Biennial, Change of Ownership, and Initial Registration in California.
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Blow-by
The gases that go around or "blow-by" the piston rings that form the seal between pistons and the
cylinder walls as an engine operates. Even in engines kept operating perfectly, some volume of
gas always leaks past the piston rings into the crankcase. As engines wear due to age or poor
maintenance the amount of "blow-by" increases.
BTDC (Before Top Dead Center)
The measurement, in degrees of rotation, before a piston reaches the top of its compression
stroke.
See Ignition Timing
Bureau of Automotive Repair (BAR)
Part of the California Department of Consumer Affairs. The Bureau of Automotive Repair (BAR) is
a consumer protection agency focused exclusively on automotive repair issues.
BAR licenses
• auto repair dealers,
• Smog Check stations, and
• Smog Check inspectors.
BAR administers the Smog Check program, as required by law. BAR investigates complaints
from consumers about auto repair establishments, and recovers millions of dollars for consumers
each year. BAR is completely separate from the Department of Motor Vehicles and the Air
Resources Board.
CAP (Consumer Assistance Program)
The Consumer Assistance Program (CAP) is available at participating Gold Shield stations for
motorists whose vehicles have failed their biennial Smog Check. CAP currently will provide up to
$500 toward the cost of repairs that allow a vehicle to pass the Smog Check. At this time owners
who choose to retire their vehicle rather than repair it may receive $1,000 or $1500 under the
CAP program.
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Carbon Dioxide (CO2)
A colorless, odorless gas which is a byproduct of most combustion processes and also of human
respiration. It is the same gas found in soda pop. High levels of CO2 in exhaust typically indicate
greater engine efficiency; however, CO2 is considered a greenhouse gas that may cause global
warming. High or low levels of carbon dioxide emissions are not grounds for a vehicle failing the
Smog Check; the measurement is meant as a diagnostic tool for inspectors. CO2 is measured in
percent.
Carbon Monoxide (CO)
Carbon Monoxide is a colorless, odorless gas that is fatal to many life forms in moderate
concentrations. CO emissions are often the byproduct of an overly rich fuel mixture. Unhealthy
levels of CO emissions result in a vehicle failing its Smog Check. CO is measured in percent.
CAT (Catalytic Converter)
Located between the exhaust manifold and the muffler, this device uses precious metals as a
catalyst to turn hydrocarbons, carbon monoxide, oxygen, and oxides of nitrogen into carbon
dioxide and water vapor.
Catalytic Converter (CAT)
Located between the exhaust manifold and the muffler, this device uses precious metals as a
catalyst to turn hydrocarbons, carbon monoxide, oxygen, and oxides of nitrogen into carbon
dioxide and water vapor.
Certification
Indicates whether a vehicle was manufactured to meet United States Environmental Protection
Agency or more stringent California emissions standards. Some vehicles were not manufactured
to meet either criteria. These vehicles are considered "Grey Market" and require additional steps
to pass a Smog Check inspection.
Change of Ownership Area
An area which meets the Federal Air Quality Standards.
Smog check inspections are only required on vehicles changing ownership and out of state
vehicles initially being registered in California. These areas require only a TSI test.
CO (Carbon Monoxide)
A colorless, odorless gas that is fatal to many life forms in moderate concentrations. CO
emissions are often the byproduct of an overly rich fuel mixture. Unhealthy levels of CO
emissions result in a vehicle failing its Smog Check. CO is measured in percent.
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CO2 (Carbon Dioxide)
A colorless, odorless gas which is a byproduct of most combustion processes and also of human
respiration. It is the same gas found in soda pop. High levels of CO 2 in exhaust typically indicate
greater engine efficiency; however, CO2 is considered a greenhouse gas that may cause global
warming. High or low levels of carbon dioxide emissions are not grounds for a vehicle failing the
Smog Check; the measurement is meant as a diagnostic tool for inspectors. CO 2 is measured in
percent.
Coolant Temperature Sensor (CTS)
A sensor used to measure the vehicle’s engine coolant temperature that sends the signal to the
on-board computer for processing.
CTS (Coolant Temperature Sensor)
A sensor used to measure the vehicle’s engine coolant temperature that sends the signal to the
on-board computer for processing.
Cylinders
The number of combustion cylinders in the engine (typically 4, 6, or 8).
Dashpot
A mechanical device that slows the closing of the throttle plate.
When upon sudden deceleration high emissions are produced, the dashpot slows the closing of
the throttle plate, effectively reducing emissions.
Defective
Defective is an obvious condition of an emission control system or component noticed during the
visual inspection, due to normal wear, or deterioration, or unintentional disturbance that will affect
the operation of an emission control component or system. It is not a condition that occurs as a
result of tampering. N unintentional disturbance includes, but is not limited to, a hose, wire, cap,
or thermal valve or switch, disturbed and not reconnected or corrected when the vehicle was
serviced.
Diagnostic Trouble Code (DTC)
Computerized engine control systems have a certain amount of built-in self-diagnostic capability
to detect problems that affect engine performance and emissions. When a fault is detected the
computer will store a diagnostic trouble code in its memory and illuminate the “Check Engine”
light also known as the Malfunction Indicator Light.
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Directed Vehicle
In order to comply with state law, the California Department of Consumer Affairs/Bureau of
Automotive Repair (DCA/BAR) directs a portion of the vehicles registered in Enhanced Smog
Check Areas to Test-Only and Gold Shield stations. These vehicles are called Directed Vehicles.
Enhanced Areas are those parts of the state with "serious," "severe," or "extreme" ozone pollution
problems.
DLC - (Diagnostic Link Connector)
A connector to link the on-board computer, with an external diagnostic tool.
DMV (Department of Motor Vehicles)
Commonly used acronym for the California Department of Motor Vehicles.
DMV ID Number
A number used to locate the electronic smog certificate in the event it is electronically misfiled.
DTC (Diagnostic Trouble Code)
Computerized engine control systems have a certain amount of built-in self-diagnostic capability
to detect problems that affect engine performance and emissions. When a fault is detected the
computer will store a diagnostic trouble code in its memory and illuminate the “Check Engine”
light also known as the Malfunction Indicator Light.
Dynamometer
A treadmill-like device that simulates driving conditions.
ECM (Engine Control Module)
Vehicle's onboard computer system.
ECS (Emission Control System)
The Emission Control System (ECS) is made up of a number of separate emission control
components which, together, reduce the level of pollutants emitted from a vehicle.
EGR (Exhaust Gas Recirculation) System
The vehicle's Exhaust Gas Recirculation system reroutes exhaust gases back through the intake
manifold to lower engine temperatures and, in so doing, reduces NOx emissions.
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EGR Functional test
The EGR Functional test is part of the Two Speed Idle test (TSI), but is not necessary for the
ASM test that tests for NOx.
During the Smog Check inspection, the inspector performs a functional test of the EGR system
per the vehicle manufacturer's instructions. This ensures the EGR system is operating as
designed. The vehicle will either pass or fail the EGR Functional test based on observations
made by the inspector during the test.
EGR Visual test
As part of the Smog Check inspection, the inspector performs a visual inspection of all emission
components the vehicle is equipped with, including the EGR system. The inspector visually
inspects the EGR valve and associated plumbing for defects or modifications. The inspector will
either pass or fail the EGR System Visual test based on observations made during the test.
EIS (Emission Inspection System)
The equipment used to analyze tailpipe gases during the Tailpipe Emissions test.
Legally valid analysis may only be done using a BAR approved EIS.
This system allows the Smog Inspector to perform a Smog Check inspection. The EIS consists of
a 5-gas analyzer, additional hardware, software, fuel cap tester, and a dynamometer with safety
restraints. The most distinctive component of the EIS is the dynamometer, a treadmill-like device
that simulates driving conditions. When necessary, the EIS can perform a Two-Speed Idle test on
vehicles that cannot be physically tested on a dynamometer. Pictured is the "BAR 97".
Emission Standards Category (ESC)
ESCs are the pass/ fail emission level cut points for a specific class of vehicles. ASM tested
vehicles from 1976-1995 have unique cutpoints based on their specific model year, make, model,
vehicle type, certification type, test weight, engine size, and transmission type. Vehicles that do
not have vehicle specific ASM cutpoints will use the ESC cutpoint classes.
Emissions Test
The third of the three vital parts of the California Smog Check. This is where the emissions
analyzer tests actual emissions from your vehicle, as measured at the tailpipe. Only the
emissions test can label a car a Gross Polluter. Gases measured include Carbon Monoxide (CO),
Carbon Dioxide (CO2), Hydrocarbons (HC) and Oxygen (O2). In California's most polluted urban
areas (Enhanced Areas), the emissions test also measures levels of Oxides of Nitrogen (NOx).
Engine Control Module (ECM)
An on-board computer processor.
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Engine Size
Measurement of piston displacement made in either, cubic inches, cubic centimeters, or cubic
liters.
Enhanced Area
Urbanized areas of the state which are classified by the Federal Environmental Protection
Agency as serious, severe, or extreme non-attainment areas for ozone or a moderate or serious
non-attainment areas for carbon monoxide with a design value greater than 12.7ppm. In these
areas BAR operates the Enhanced (most stringent) Smog Check Program, requiring an ASM
dynamometer test on vehicles if viable.
ESC (Emission Standards Category)
ESCs are the pass/ fail emission level cut points for a specific class of vehicles. ASM tested
vehicles from 1976-1995 have unique cutpoints based on their specific model year, make, model,
vehicle type, certification type, test weight, engine size, and transmission type. Vehicles that do
not have vehicle specific ASM cutpoints will use the ESC cutpoint classes.
ET System
An electronic link between Bureau of Automotive Repair, Department of Motor Vehicles, and
Smog Check Stations along with inspectors. The link is used to transmit information from one to
another.
EVAP (Evaporative Emission Control System)
The EVAP system prevents raw gasoline from escaping the vehicle and evaporating into the
atmosphere. As part of the inspection, the inspector visually inspects the EVAP system and
associated plumbing for defects or modifications. The inspector will either pass or fail the EVAP
system based on observations made during the test. (See also LPFET.)
Exhaust
1. The exhaust gases produced by fuel combustion in an engine.
2. The system of pipes that conducts exhaust gases safely from the engine to the
atmosphere. Usually either single (one pipe) or dual (two pipes). Includes the tailpipe,
muffler, and catalytic converter.
Exhaust Gas Recirculation System (EGR)
The vehicle's Exhaust Gas Recirculation system reroutes exhaust gases back through the intake
manifold to lower engine temperatures and, in so doing, reduces NOx emissions.
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Fail
An unacceptable level on any portion of the test (i.e. Functional, Visual, or Tailpipe).
A failure of the entire Smog Check inspection indicates that the level of harmful emissions from
this vehicle, on one or more portions of the test, exceeds the standard for this model/engine
combination, and is contributing to unhealthy air in California.
Any result of a Visual, Functional, or Tailpipe emission test that is above the standard acceptable
level.
Fillpipe Restrictor
A functional test of the fuel pipe restrictor is no longer performed on vehicles being registered in
California.
The EIS may prompt for the fillpipe restrictor test for vehicles undergoing an initial Smog Check
inspection.
If this happens, enter "N" into the EIS fillpipe test prompt.
Fuel Cap Integrity Test
Tests whether gasoline fumes can leak out from your tank around the cap. Gasoline fumes
contain high levels of harmful pollutants, including benzene, a known carcinogen. Studies by the
United States Environmental Protection Agency show that around 30 percent of all the emissions
from a vehicle are in the form of fuel evaporation, usually from the fuel tank. The EIS will either
pass or fail the fuel cap based on the observation made during the test.
Fuel Cap Visual Test
As part of a Smog Check inspection, the inspector visually inspects the fuel tank cap for defects,
(i.e. cracked or deteriorated rubber seal). The inspector will either pass or fail the fuel cap visual
test based on observations made during the test.
Fuel Evaporative Controls
The EVAP system allows for proper fuel system ventilation while preventing fuel vapors from
reaching the atmosphere. This system catches and stores vapors from the fuel system and fuel
tank while the engine is off, which is when most fuel evaporation occurs. When the engine is
started, these fuel vapors can be removed from storage and burned. In most systems, storage is
provided by an activated charcoal (or carbon) canister.
Fuel Type
The type of fuel the vehicle is operating on when it arrives at a Smog Check station.
G = Gasoline
D = Diesel
P = Propane
N = Liquid or Compressed Natural Gas (LNG/CNG)
M = Methanol >20%
E = Ethanol >20%
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Functional Inspection
The second of the three vital parts of the California Smog Check.
These tests check the mechanical functioning of various systems in the vehicle. The systems are:
EGR, MIL, OBD II, Ignition Timing, Fuel Cap, and Evaporative Emissions via LPFET.
Emissions system defects identified during the functional test inspection are considered
unhealthy for the air and result in an overall Smog Check failure.
GP (Gross Polluter)
The emissions level, or "cut point," at which a vehicle fails as a Gross Polluter. The emissions of
a gross polluter are typically at least twice as high as those of an ordinary failing vehicle. Repairs
on a Gross Polluter must be verified at a Test-Only or Gold Shield station.
Grey Market Vehicle
A vehicle originally manufactured for sale outside the United States and not designed to meet
California or Federal emission standards is a grey market vehicle.
Before most grey market vehicles can be registered in California they must be modified and
tested by an ARB Certified Laboratory to meet California emissions standards.
During this process, a California Certificate of Conformance (CCC) is issued indicating the vehicle
has been successfully modified and tested. The CCC also lists the required emission controls.
GVWR (Gross Vehicle Weight Rating)
Gross Vehicle Weight Rating is the weight of the vehicle plus the maximum load it is designed to
carry (the weight of the vehicle itself plus fuel, passengers, cargo, and trailer tongue weight). This
differs from the vehicle's test weight. GVWR is usually listed on a vehicle's identification label
located on most vehicles' driver's side door.
HC (Hydrocarbons)
Hydrocarbons are the component of fuels that produce energy. HC emissions from a vehicle are
basically unburned fuel. High levels of HC emissions indicate incomplete fuel combustion, either
as the result of a misfire or of low engine compression. Unhealthy levels of HC emissions result in
a vehicle failing its Smog Check. Hydrocarbons are measured in parts per million (PPM).
Ignition Timing (or simply "timing")
The timing of the spark relative to the operation of the valves and the placement of the piston in
the cylinder. BTDC stands for "Before Top Dead Center" often indicated by a mark on the main
pulley on the front of the engine. For most engines, when the timing is set to 0 degrees BTDC the
number one sparkplug will fire at the very top of the number one piston's stroke.
Advanced timing is when the spark fires before the piston has reached the top of the stroke.
Retarded timing is when the spark fires after the piston has reached the top and has already
started to descend.
For vehicles where the manufacturer specifies a timing setting, the Smog Check inspection allows
plus or minus three degrees from that setting. For vehicles where the manufacturer specifies a
timing range, the vehicle must be within that timing range.
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Inspection Reason
Either biennial (in conjunction with a DMV registration renewal notice), change of ownership
(selling a car), or initial (first time registered in California).
KOEO (Key On, Engine Off)
Some on board computer testing is done with the key in the on position but with the engine off.
KOER (Key On, Engine Running)
Some on board computer testing is done with the key on and the engine idling.
License
The California license plate number on the vehicle. If there is not plate, "NONE" is entered into
the EIS.
LPFET (Low Pressure Fuel Evaporative Test)
Testing of the vehicle system's ability to contain fuel vapors and prevent them from evaporating
into the atmosphere.
Make
The vehicle manufacturer's brand name.
Manifold Absolute Pressure (MAP)
The amount of pressure in the engine’s intake manifold. Usually used in reference to the MAP
Sensor, which senses vacuum or pressure in the air intake system.
MAX (Maximum Emission)
The maximum allowable emissions for the particular make, model, and year of vehicle. Vehicles
with emissions that exceed this level, or "cut point," fail the emissions portion of the Smog Check.
There are separate cut points for vehicles failing at maximum vs. Gross Polluter levels.
MEAS (Measured Emission)
The amount of each specific pollutant measured during the Emissions test of the vehicle.
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MIL (Malfunction Indicator Light)
Also known as the "Check Engine Light" and as the "Service Engine Soon" light this early
warning signal on the instrument panel indicates engine problems. Such problems could cause
serious performance or engine problems for the vehicle if not checked and repaired, and could
lead to excessive amounts of pollution being emitted during certain driving conditions which may
not be detected during a Smog Check.
Therefore, if the MIL is on or does not work, the vehicle will fail the Smog Check.
Missing
A missing emission control system or component is one which all or part has been removed from
the vehicle or engine.
Model
The vehicle manufacturer's model name.
Model-Year
The vehicle manufacturer's model year for the vehicle. Not necessarily the year the vehicle was
built.
Modified
An emission control system or component has been modified if:
It has been disabled even though it is present and properly connected to the engine
and/or vehicle;
It has been replaced with a component not marketed by its manufacturer for street use on
the vehicle,
An emissions related component of the system has been changed such that there is no
capacity for connection with or operation of other emissions control components or
systems.
NOX (Oxides of Nitrogen)
Oxides of Nitrogen are odorless gases that help form Smog, and give Smog its characteristic
brown color. NOx is produced when temperatures in the combustion chambers exceed 2500
degrees Fahrenheit. Excessive engine combustion chamber temperature could be caused by a
lean fuel mixture, advanced timing, carbon buildup, malfunctioning EGR or a malfunctioning
engine cooling system.
The function of the EGR System is to reduce NOx. Unhealthy levels of NOx emissions result in a
vehicle failing its Smog Check. NOx is measured in parts per million (PPM).
O2
Oxygen is a colorless, odorless gas necessary for life on the planet and also for engine
combustion to occur. The atmosphere is comprised of approximately 21% Oxygen. High levels of
O2 in the exhaust indicate a problem with the catalytic converter. High or low levels of O 2
emissions are not grounds for a vehicle failing the Smog Check; the measurement is meant as a
diagnostic tool for inspectors. O2 is measured in percent.
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OBD II
The acronym for On-Board Diagnostics II, the second generation of on-board self-diagnostic
equipment required in California and Federal vehicles. Diagnostic capabilities are incorporated
into the hardware and software of a vehicle's computer to monitor virtually every component that
can affect emission performance. Each component is checked by a diagnostic routine to verify
that it is functioning properly. If a problem or malfunction is detected, the OBD II system
illuminates a warning light on the vehicle's instrument panel to alert the driver. Typically this
warning light will display the phrase "Check Engine" or "Service Engine Soon." The system will
also store important information about the detected malfunction so that a repair technician can
accurately find and repair the problem.
Odometer
The number of miles on a vehicle as reported by the inspector based on their reading of the
vehicle's odometer.
OEM (Original Equipment Manufacturer)
Parts obtained from the manufacturer of the vehicle.
Oxides of Nitrogen (NOx)
Oxides of Nitrogen are odorless gases that help form Smog, and give Smog its characteristic
brown color. NOx is produced when temperatures in the combustion chambers exceed 2500
degrees Fahrenheit. Excessive engine combustion chamber temperature could be caused by a
lean fuel mixture, advanced timing, carbon buildup, malfunctioning EGR or a malfunctioning
engine cooling system.
The function of the EGR System is to reduce NOx. Unhealthy levels of NOx emissions result in a
vehicle failing its Smog Check. NOx is measured in parts per million (PPM).
Oxygen Sensor (O2)
A device located in the exhaust manifold or exhaust pipe which compares the level of Oxygen in
the ambient air to the level of Oxygen in the exhaust stream and sends a signal to the vehicle's
onboard computer, which adjusts the air/fuel mix accordingly. Also called "the O 2 Sensor".
Ozone (O3)
A chemical formed by the interaction of Hydrocarbons and Nitrogen Oxides when struck by
sunlight.
Ozone is a respiratory irritant that can reduce lung function, aggravate asthma, emphysema,
bronchitis, and other chronic lung diseases, as well as inflame and damage the lining of the
lungs.
Animal studies indicate that Ozone may also lower the body's resistance to respiratory infection.
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Partially Enhanced Area
Areas with higher pollution levels requiring an ASM Smog test on all vehicles if viable, with no
vehicles mandated to be tested at a Test Only center.
Pass
A positive result in any one of the Visual, Functional, or Tailpipe inspections. Also, a Pass for the
entire Smog Check inspection would indicate that the level of harmful emissions from this vehicle,
on all portions of the test, is within the range of what is reasonable for this model/engine
combination.
PCV (Positive Crankcase Ventilation)
Positive Crankcase Ventilation removes unburned gases blown around the pistons and rings from
the engine crankcase, and reroutes them through the intake manifold to be burned.
Percent
The unit used to measure CO, CO2, and O2. 1% equals 10,000 ppm.
Pollutant
Waste material that pollutes the air.
PPM (Parts per Million)
This is a unit of measurement for both Oxides of Nitrogen and Hydrocarbons which are measured
by the emission analyzer.
Regular Test and Repair Station
Regular Test and Repair stations perform inspections and repairs on all types of vehicles. This
station type is not allowed to certify Directed (Test Only) vehicles or Gross Polluter vehicles.
Repair Tech Name / Number
The name and license number of the licensed Smog Check technician who repaired the vehicle, if
applicable or known.
RPM (Revolutions Per Minute)
A measurement of engine speed. Engine turning speed typically does not correspond to the
speed of the vehicle.
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Smog
The word Smog is a combination of the words "smoke" and "fog".
Classic Smog results from the combination of smoke and Sulfur Dioxide.
Modern or photochemical Smog results when Nitrogen Oxides (NOx) and Volatile Organic
Compounds (VOCs), also known as Hydrocarbons (HC), are struck by sunlight and form
particulates and ground-level Ozone.
Smog Check Certificate Number
This is the number of the electronic certificate sent to the Department of Motor Vehicles (DMV)
which allows the owner to complete their registration. The Vehicle Inspection Report is proof of
the vehicle passing a Smog Check.
Software Version / EIS Number
The BAR-certified version of the software that the emissions inspection system used during the
test and the unique identification number for that specific EIS.
SPK (Spark Control)
Mechanical or electronic devices and systems that control ignition timing.
State
The issuing State of the license plate on the vehicle.
Station Number
The license number of the Smog Check station where the test was performed.
TAC (Thermostatic Air Cleaner)
Preheats cold air being drawn into a cold engine to help fuel vaporize before burning. This system
is important before the engine warms up to improve cold driveability and reduce cold-engine
emissions.
Tach (Tachometer)
A gauge used to display the engine’s speed in Revolution Per Minute (RPM).
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TAS (Test Analyzer System)
See EIS
Technician Name / Number
The name of the licensed Smog Check technician who performed the test, and their individual
license number.
Test Only Station
A Test Only station is authorized to test and certify all vehicles, but may not perform any repairs.
Test Weight
The actual weight of the vehicle's drive axle as measured during the Smog Check.
Toxics
Harmful substances.
TPS (Throttle Position Sensor)
A potentiometer used to measure the position of the throttle opening and send the signal to the
on board computer for processing.
Transmission
The mechanism that connects the power created by the engine to the differential and wheels.
May be either manual (3, 4, 5, or 6 speed) or automatic.
TSB (Technical Service Bulletin)
A bulletin issued to auto dealers and repair technicians by the manufacturer detailing a fix for a
known concern. The bulletin is for informational purposes only, it is not a recall. Dealers and
technicians are under no obligation to make the repair or notify customers. TSB's are intended to
assist in ongoing repairs.
TSI (Two-Speed Idle test)
When necessary, the EIS can perform the Two-Speed Idle test on vehicles that cannot be
physically tested on the dynamometer. For example when a vehicle is full-time 4wd or has nondisengaging traction control. The TSI inspection includes two test sequences; a 2500 rpm test
and an idle test. A TSI is also done in a Change of Ownership Area where only TSI tests are
required.
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Type
Vehicles eligible for the Smog Check program include passenger cars, light-duty trucks and
heavy-duty trucks, motor homes, and Government Fleet vehicles.
Vacuum Lines to Sensors/Switches
A visual inspection of the vacuum lines to the sensors and switches in all of the emission control
systems on the vehicle is performed. The inspector will either pass or fail these components
based on observations made during the test.
VECI (Vehicle (Underhood) Emission Control
Information label)
A label attached under the vehicle’s hood with the vehicle’s tune-up and emissions system
information.
VID (Vehicle Information Database)
The VID is maintained by BAR and contains registration data from DMV plus Emission Control
System (ECS) data, Smog Check history, vehicle profiling data, station and inspector data, and
certificate sales data.
VIN (Vehicle Identification Number)
Your vehicle's unique identification number, usually 17 digits but sometimes less. Typically found
on the top of the dash just inside the windshield on the driver's side, or on a plate/sticker in the
driver's side door jamb. The bar code on your DMV registration renewal also contains this
number. Contact the DMV if the VIN on your vehicle does not match the VIN on your registration
form.
VIR (Vehicle Inspection Report)
The vehicle inspection report is the printout given to the consumer after the Smog Check has
been completed. It includes the pass/fail results of the inspection as well as the readings obtained
during the emissions portion of the test. It also includes the station and inspector information.
Visual Inspection
The first of the three vital parts of the California Smog Check. The Visual Inspection checks for
missing, disconnected, or visibly damaged emissions-system components, including the catalytic
converter, thermostatic air cleaner, heat riser and Smog pump. Emissions system defects
identified during the visual inspection result in an overall Smog Check failure and lower air quality.
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VLT / VLT Record #
Vehicle Look-up Table (VLT) is the list of vehicle ESCs maintained by BAR.
A vehicle's ESC (Emission Standards Category) record contains specific information for each
vehicle model and engine combination available. Information from the VLT regarding a vehicle's
weight and aerodynamic resistance allows the Smog Check emissions analyzer to correctly set
the resistance on the dynamometer.
VOCs (Volatile Organic Compounds)
Organic chemical compounds, also known as Hydrocarbons (HC), that significantly vaporize
(evaporate) and enter the earth's atmosphere under normal temperature and pressure conditions.
VOCs react with NOx and sunlight to form Photochemical Smog.
Wiring to Sensors/Switches
A visual inspection of the wiring to the sensors and switches in all of the emission control systems
on the vehicle is done. The inspector will either pass or fail these components based on
observations made during the test.
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