How to Understand the Check Engine Light

The "check engine "light" what it means... Presented by Auto Service Tech.com all rights reserved Ever have this light come on in your car? Want to know what is means? This is the "Check engine" light and it was turned on by this guy... The engine control module a computer in charge of all your engine does the ECM for short; it is responsible for making sure the emissions from your car stay in line. That keeps this guy... the catalytic converter... happy and your tailpipe emissions low... like any computer, it needs information. A provide of sensors provide that information. Sensors like this airflow sensor, or MAF so the ECM knows how much air is getting in. and sensors like the camshaft position sensor... so the ECM knows where the pistons and valves are. Once it has the information, it responds according to its programming. It controls ignition... and fuel delivery.... In the correct amounts and at the correct time. It also keeps an eye on these systems by running tests of its own. It tests the circuits for electrical problems, and the sensors/output devices for function. The check engine light means that a test run has failed, and will affect emissions. Any emissions on today's cars... including fuel vapor escaping from the fuel tank. Some problems are severe enough to require immediate attention. Some will not affect the way the car drives at all. The only way to find out is to ask the computer what test failed. This is done by connecting a special tool, called a scan tool, to the computer. You can then ask the computer what it saw wrong. And get an answer like this one... the computer can't tell you exactly what is wrong... only what system and component that may be affected. Something as simple as a loose wiring connection may be all that caused it. Or a part may have failed from age and wear. A trained tech can use pinpoint tests to isolate the problem. And repair your car. So the next time you see this... trust a pro to help you tell whether it's a big problem, or a minor fix. For more information visit us at: autosetvicetech.com And thanks for watching! We hope it helps... www.AutoserviceTech.com Produced by Peter F, Meier