What does the check engine light mean?

Answer 1

The check engine light means that there is a posssible problem with the engine . There is not one specifc problem that it could be. The dealership can look at the chip and figure out the specific problem and get you going in the right direction. Apparently, if the light comes on intermittendly, immediate check-up is required, when it stays on solid, the diagnosis can be delayed for a little while. Often on 1995 and older models of the Chevy Cavalier, the "Check Engine Light" will be due to a problem with your Emissions. The wisest thing to do is take it to your local chevy dealer and have them service your engine for a small fee. My check engine light has been on for two and a half years and my car shifts hard. I went to a dealer and they told me it was my speed sensor saying there is a slip in the trany that wasnt there so it Was putting to much pressure in my trany lines cause the car to shift hard my ets off light is also on they tried to tell me it was the motor mounts. Danielle-Owner of a 98 chevy cavalier Z24. The " check engine light" is by far one of the most misunderstood technological advances It is a warning light that is illuminated when there is a problem affecting the EMISSIONS of the vehicle.. Don't let it bother you as it is a good thing once you understand it. One point that was brought up a recent meeting of technicians was that the amount of hydrocarbons is greater when the gas cap is left off than when the engine is running. Hydrocarbons are part of pollution emitted as gasoline evaporates. Going a step farther, one facet of the emission system is the "Evaporative" portion. This is when the fumes from the gasoline are leaking from the system into the outside air. This is one part of the emission system that can trigger a check engine light. I would say a small percentage of the vehicles that have a check engine light are the result of a loose or inadequate gas cap. But understand that many scenarios are possible with the "check engine light" The vehicle's powertrain computer (note that some vehicles have multiple computers aside from the powertain computer) will run a series of self-tests. They will only run under certain criteria. And they are different from manufacturer to manufacturer. Some self-tests or

Answer 2

The " check engine light" is by far one of the most misunderstood technological advances by the public. I am sure I will revise this as time goes on as it is an in-depth understanding for the public. It is a warning light that is illuminated when there is a problem with the EMISSION SYSTEM only. Emission system being the pollution control system. Don't get a hard on against it as it is a good thing once you understand it. One point that was brought up a a recent meeting of technicians was that the amount of hydrocarbons is greater when the gas cap is left off than when the engine is running. Hydrocarbons are part of pollution emmitted as gasoline evaporates. Going a step farther, one facet of the emission system is the "Evaporative" portion. This is when the fumes from the gasoline are leaking from the system into the outside air. This is one part of the emmission system that can trigger a check engine light. I would say that about 7% of the vehicles that have a check engine light are the result of a loose or inadequete gas cap. But understand that many scenarios are possible with the "check engine light" The vehicle's powertrain computer (note that some vehicles have 17 different computers) will run a series of self-tests. They will only run under cetain criteria. And they can be vastly different from manufacturer to manufacturer. Some self tests are not run until preceding ones have run successfully. So if there is a problem in one particular area that is preventing another self test from running, you can have a situation where one problem is fixed, but another still exists. If you fix a problem and drive the car through a drive cycle that sets the monitor (or self test) the light will go off as it passes that criteria that triggered it in the first place. After 1996, the auto industry went to a idea called OBD II (on board diagnostics). This was to get all the manufacturers onto a similiar plane for troubleshooting and powertrain control. While they still differ vastly, many corrections and adaptations were made for technicians to better fix the check engine light problems. Prior to this there were so many different and poor troubleshooting data from a check engine light problem that resolving the problem was much more difficult. Many early warning light of this nature were set to illuminate based on miliage. An Oxygen sensor was one of the things that were meant to be replaced when that miliage was hit. This is much like many current "Change oil lights", that are set based on a pre-set miliage. Pukenstein@aol.com
What does the "Check Engine" light mean? When the "Check Engine" light comes on and stays on while the vehicle is running, it means that the on-board computer (known as the Electronic Control Module, or ECM) has detected a problem in one of the many systems it monitors and controls. The problem may be minor but it could be serious. What if the "Check Engine" light comes on but my car is still running okay? The best thing about the 'Check Engine' light is that it lets you fix little problems before they become big, expensive problems. And not every problem gives you obvious indications (hard starting, rough running, stalling, etc.) that something is wrong. That's why you can't ignore this important little light. The 'Check Engine' light also alerts you to problems like poor gas mileage or reduced performance. These can evolve so slowly that you get used to them. But your on-board computer is sensitive enough to detect even gradual changes, then let you know when something is wrong. What will you do when I bring in my vehicle? When you come to us with the "Check Engine" light on, we connect your vehicle's computer to our computer. Your car's computer is able to give our computer a trouble code, indicating why the "Check Engine" light was activated. Once we correct the problem your car's computer makes sure everything is back to normal, then turns off the "Check Engine" light. Today's on-board computer technology allows us to quickly see if all vehicle systems are operating normally. While our computer is connected to your car, we can check idle speed, throttle response, engine temperature, fuel system pressure, manifold vacuum, exhaust emission levels and other key indicators, all through your vehicle's ECM. While computer technology can direct us to potential problems, nothing can replace the skills and knowledge of a trained technician. Working with the computer, our staff can thoroughly diagnose and correct any problems your vehicle may have. What does the on-board computer do? The computer processes information it receives from the sensors, then sends out commands to the systems it controls. This includes your car's fuel delivery, spark timing and emission control systems. Most of the time, your on-board computer is hard at work and you're not even aware of it. But when it needs your help, it turns on the 'Check Engine' light. That's your vehicle's way of saying 'Take me to a qualified service technician right now!' If my vehicle needs new parts, what kind should I get? When replacing parts, always insist on a brand that meets or exceeds the specifications established by your car's manufacturer. Many high-quality replacement parts actually work better than the original part your car was built with, because they include improvements to the original design. The engine management components we sell are manufactured to meet or exceed all original equipment specifications. We also recommend our products because we can get the right parts and make the repair for you more quickly. Want to know more? If this brochure hasn't answered all of your questions about the "Check Engine" light, just We are fully trained and qualified. Remember, whenever you see the light, be sure to see us, too. Bring your car in now and we can perform an 11-point Engine Performance Check 1. Check for any trouble codes in the computer 2. Check engine RPM 3. Check throttle position sensor output 4. Check airflow/density 5. Check fuel correction measurements 6. Check oxygen sensor readings 7. Check air-intake hoses for cracks and leaks 8. Check engine coolant and air temperature 9. Check output signals 10. Check air filter condition 11. Check PCV valve system Remember When the 'Check Engine' light comes on and stays on, you need to see a qualified service technician right away! ALSO: If the Check Engine light comes on following a bang and violent lurch of the car, get your alternator checked. I have lost 2 altenators through that...
The check engine light comes on and stays on when a problem is detected by the self diagnosis system of your vehicle.

Generally, a check engine light is lit when there is a problem in the emissions or somthing that is affecting the effectiveness of the emissions.