Deciphering Vehicle Emissions Control Information

For most makes and models of cars, trucks and SUV’s a vehicle emissions control information sticker can be found somewhere under the hood, usually close to the front and right side of the inside of the hood where it is clearly visible. The purpose of this decal is to provide the mechanic with the specific vehicle emissions control information that will be needed when repairing or working on the engine.

There are several abbreviations used on the vehicle emissions control information sticker and they include:

BPA by pass air
CONV conventional system
EGR exhaust gas recirculation
EGR BPT exhaust gas recirculation back pressure transducer
EVAP evaporative emission
EVAP CSP evaporative emissions canister storage/purging
IAC idle air control
IAC FIC idle air control fast idle control
PCV positive crankcase ventilation
TI transistorized ignition
WU-TWC warm-up three way catalytic converter
UB underbody
TWC three way catalytic converter
VCC vacuum cut control solenoid

As a vehicle owner you won’t need to know or remember these terms, however the vehicle emissions control information sticker and the schematic drawing that shows these different areas of the engine are essential for your repair professional.

The easiest way for a driver to know when the vehicle has noted a problem with in the vehicle emissions control system is that the malfunction light will come on in the dash. Depending on the model and type of vehicle that you drive the light will be different. Typically there is some type of “check engine” message that is associated with the particular in-dash system, but in addition the vehicle will also store a record of what was happening in the engine within the computer memory. When you take your vehicle to the repair shop their diagnostic computer interacts with your vehicle computer chip, allowing the computer to literally help diagnosis the malfunction in your vehicle. In order to properly set and repair the vehicle, the vehicle emissions control information that is specific to your vehicle and engine will be used.

The computer system will also clear itself after so many drive cycles are completed without the same fault or detection occurring. Depending on the make and model of your vehicle the number of drive cycles needed to clear the system will vary, but it is typically around three. This means that if the reading was an abnormality that doesn’t repeat, the car will actually reset it own computer chip and will cease to continue to alert the driver through the indicator light.