What is OBD2?
OBD2—an advanced "on-board" computer system responsible for monitoring your vehicle's engine, transmission, and emissions control components. If your "Check Engine" light comes on and stays on, your OBD system is telling you that it has detected a problem with your vehicle. In addition to protecting the environment, this light, and the OBD2 system behind it, can save you time and money by identifying minor problems before they become major repair bills.
OBD also plays a key role in nearly 30 state and local vehicle emissions testing programs around the country. In these areas, technicians use OBD2 checks to identify vehicles that are in need of repair and therefore are exceeding emissions standards. As a result, OBD2 serves as an important tool in improving air quality and helping states meet national air quality standards.
How does the system work?
Today’s vehicles are highly sophisticated and efficient. All 1996 and newer cars and trucks have an advanced powertrain control computer that uses second generation on-board diagnostics (OBD-II) technology to manage and monitor the operation of the engine, transmission, and emissions control components. OBD keeps your engine running at peak efficiency and will alert you when repairs are needed.
How do I know the OBD system is working correctly?
When you turn on the ignition, the “Service Engine Soon” or “Check Engine” light should flash briefly, indicating that the OBD system is ready to scan your vehicle for any malfunctions. After this brief flash, the light should stay off while you drive as long as no problems are detected.
What does it mean if the light turns on while I'm driving?
If the light comes on and stays on, the OBD system has detected a problem. Your vehicle might have a condition that wastes fuel, shortens engine life, or causes excessive air pollution. If left unaddressed, these conditions could also damage your vehicle and lead to increasingly expensive repairs. For example, OBD can identify a loose or missing gas cap (which wastes fuel and contributes to smog) or engine misfire (which can lead to severe or permanent engine damage).
What should I do if the light stays on?
• There is no cause for panic. The vehicle is just telling you to seek attention soon.
• When you reach your destination, make sure the gas cap is not loose or missing. Always turn off your engine when refueling.
• If the light does not go out after a few short trips following gas cap replacement or tightening, have your vehicle serviced by a qualified repair technician soon! Delaying assistance could lead to more expensive damage.
What does it mean if the light is blinking?
If the light is blinking, a severe engine problem such as a catalyst-damaging misfire is occurring and should be addressed as soon as possible. You can still drive safely, but should minimize your time on the road. Try not to drive the vehicle at high speed or with excess weight (such as towing or carrying heavy equipment).
What will my technician do when I take my vehicle into the shop?
Ask your repair shop if they employ trained OBD technicians. A modern repair shop or dealership should have an OBD scan tool to diagnose the cause of your vehicle's problem. These technicians will have the proper tools and will know best how to diagnose your vehicle.
The technician will connect a small, hand-held scanning device to your vehicle's computer (usually through a connector under the dashboard) and download information that can pinpoint the problem. The technician can then repair the vehicle based on manufacturer recommendations. OBD actually helps repair technicians do their job more quickly and reliably, helping you avoid unnecessary repairs and trips back to the shop.
What should I do if the light goes out before I take the vehicle to the shop?
Usually, nothing. If the problem that caused the light to come on is addressed, the OBD computer will turn the light off. indication of a faulty OBD system. In fact, the system is doing its job by verifying that a problem temporarily existed but has since been corrected; perhaps a loose gas cap was tightened or fouled spark plug was cleared. Your vehicle needs no special attention unless the light comes on again.
What else can I do to make sure my vehicle is running well and to minimize its environmental impact?
Today's vehicles are highly sophisticated and efficient. OBD helps to ensure these vehicles are running in top shape, but you still need to maintain your vehicle according to the manufacturer's recommended schedule. Keep up with routine maintenance and keep an eye out for your Check Engine light. Always turn off the engine before refueling and always make sure the gas cap is securely tightened. You'll save money on fuel and repairs while helping to do your part to protect the air you breathe. In addition, driving as little as possible by combining trips, carpooling, walking, biking, or using public transit are all things you can do to help minimize vehicle pollution.
Check Engine Light
The "check engine light" or "malfunction indicator lamp" (MIL) is a red light or an icon of an engine that will light up on your dash board. Although it may only indicate a minor problem, it could also be a warning of something more serious such as: problems with the fuel system, engine emission system, engine or engine performance, drive train, or electrical problems. Depending on the make and model of the vehicle you drive, the engine light may light steady or blink indicating to get the problem checked immediately. On some vehicles the icon will light only when the problem occurs while on some it will remain lit until a technician can reset it. Although the light can sometimes be reset by disconnecting the battery, this is not recommended as you will likely lose the diagnostic trouble codes logged in the vehicles computer, which will assist you in determining the cause and seriousness of the problem. These diagnostic trouble codes can be read using a CODE READER or SCANNER.
Some problems that may trigger the engine warning light include:
*Failed or failing system sensors.
*Poor engine performance which may be caused by faulty spark plugs, wiring, or clogged fuel injectors, among others.
*Emissions problems such as a loose or cracked vacuum hose, loose or missing gas cap, or a failed EGR (exhaust gas recirculation) valve.
*Electrical wiring that has a short or open circuit.
The "check engine light" will not give you any specifics of what the problem is. It is recommended that you use a scanner or code reader to read the diagnostic codes. You can also take your vehicle to your mechanic, who will have a scanner to read the diagnostic codes. Of course they will also charge a fee for this service. Having your own scanner arms you with the codes before going to the mechanic. You may even be able to correct the problem yourself. The codes narrow down the problem to a specific system and even down to the part that is causing the problem.
There are many other warning lights that could be on your dashboard. Newer vehicles give you more information from the "check engine light" to "your tires need air". Below is a list of some of the different warning lights and what they are trying to tell you.
Oil Pressure Warning Light
The "oil pressure warning light" tells you your engine is not getting enough oil pressure. This is important because your engine will not run very long if it is not getting the oil it needs to lubricate and cool it. If this light comes on, you should stop immediately. The problem may simply be that you are short of oil and need a "top up", but it could also be a worn oil pump, a faulty oil pressure sending unit and if you don't look after your vehicle, the oil could be just too thick and dirty to flow properly. If your oil level seems to be going down and you don't see any oil puddles under your vehicle, it usually means the engine is burning excessive amounts of oil. The cause could be a leaking gasket that could be relatively easy to replace, to something more serious leading to an expensive overhaul or even engine replacement.
Temperature Warning Light
The "engine temperature light" is another important warning indicator light where you should stop driving and turn off your engine immediately. Like the "oil pressure warning light" it may only be caused by a loss of radiator fluid which is easy to top up. If there are no visible leaks under the car however, the problem is most likely internal and can only be diagnosed by pressure testing the engine cooling system.
attery System Warning Light
The "generator or alternator warning light" may show an icon of a battery or may light up as a red or orange "GEN" or "ALT". It does not require you to stop immediately, but your time will be limited since you will be running off of battery alone. You can maximize your time by minimizing any accessories that may be on and even turning off your lights if it is safe to do so. The problem could be as simple as a loose or corroded battery cable, a broken or slipping drive belt or it could be a failed part like the alternator or generator.
Brake System Warning Light
If your "brake warning light" is on and your emergency parking brake is not engaged, you should not drive the vehicle. The problem could be a simple switch adjustment on the parking brake or could be a sign of something bigger. Squeaking or unresponsive breaking will most likely mean your the break fluid reservoir is low. If a top up won't get the light to extinguish, there could be a leak in the brake hose, disc brake caliper or drum brake wheel cylinder. The vehicle should not be driven until the problem is inspected and fixed.
ABS
Your vehicle may also have an "anitilock braking system warning light" (ABS) that lets you know there is a problem with the antilock brake system. Typically, you will not notice a difference under normal driving conditions, but in emergency braking the system may not work. You should have your mechanic check it out as soon as possible.
Reminder Lights
Newer vehicles try to make taking care of your car easier by including "service reminder lights". This system will calculate your engine oil life by taking into consideration driving conditions and environmental conditions, it can tell you if your air filter needs to be changed, if your tires need air, and even if your windshield washer fluid is low. These reminder lights are helpful but you should not rely on them and instead have the vehicle serviced at the recommended intervals of miles traveled or time since last service, whichever comes first. A reset tool can be used to reset these, of course you would only reset the indicator once the required maintanence is performed.
Other Warning Lights
There are many more warning lights that have not been discussed here, such as a door or trunk being ajar, fasten seat belts, airbag warning, head lights on, fog lights on . . . and many more. It all depends on the year, make, and model of the vehicle you are driving and what options are available. If you come across a light that you don't recognize, it is always prudent to check your vehicle with a code reader or scanner, it only takes a minute. Better safe than sorry!
