Mar 10, · The check engine light is part of your car’s so-called onboard diagnostics system. Since the s, computers increasingly have controlled and . The check engine light — more formally known as the malfunction indicator lamp — is a signal from the car's engine computer that something is wrong.
We respect your privacy. Chdck email chsck you provide will be used just for sending this story. Call it the most misunderstood indicator on your dashboard: The check engine light can mean many different things, from a loose gas cap to a seriously misfiring engine.
Ignore that warning and you could end up damaging expensive components. It can also be a sign that your car is getting poor fuel economy and emitting higher levels of pollutants. Since the s, computers increasingly have controlled and monitored vehicle performance, regulating such variables as engine speed, fuel mixture, and ignition timing.
In modern cars, a computer also tells the automatic transmission when to shift. The code can be read with an electronic scan tool or a diagnostic computer—standard equipment in auto repair shops. There are also a number of relatively inexpensive code readers that are designed for do-it-yourselfers. The code will typically just point lighr in the direction of the problem, and still requires an experienced professional to fully diagnose and repair the issue.
This can work in some instances, but when in doubt, seek professional help. If the check engine light illuminates, it will either blink or remain constantly illuminated, depending wnat the problem. A blinking light, or in some cars a red light instead of a yellow or orange light, indicates a problem that needs immediate attention. Either way, you should have the vehicle checked by a mechanic.
In late-model cars, a blinking fngine usually indicates an engine misfire so severe that unburned fuel is being dumped into the exhaust system, where it can quickly damage the catalytic converter, leading to an expensive repair. If that happens, you should reduce power and have the car or truck looked at as soon as possible. If the light is steady, the problem is not an emergency, but you should schedule an appointment as soon as possible.
You might have noticed the gallery of icons on your dashboard when you start your car. Sign Ejgine. Become a Member.
Remember Ligut. Forgot username or password? Not a member? Need further assistance? Please call Member Services at How to determine whether your car has a loose gas cap—or a serious engine problem. By Consumer Reports. Last updated: March 10, Sharing is Nice Yes, send me a copy of this email. Send We respect your privacy. Oops, we messed up. Try again later. When you shop through retailer links on our site, we may earn affiliate commissions. Learn more. Best Car Tires of Best Car Hhe of More on Car Maintenance.
Make Your Car LastMiles. Tip-Offs to Mechanic Rip-Offs. What to Do About the Check Engine Light If the check engine light illuminates, it will either blink or remain constantly illuminated, depending on the problem. If the check engine light comes on, here are some tips on what you should do: Look for a serious problem that how to say words in spanish with sound immediate attention.
Check your dashboard gauges and lights for indications of low oil pressure or overheating. These conditions mean you th pull over and shut off the engine as soon as you can find a safe place to do so. On some cars, a yellow check engine light means investigate the problem and a red one means stop right now.
Try tightening your gas cap. This can often solve the problem. Keep in mind that it may take several trips before the light resets. Some vehicles have a separate indicator that warns of a loose gas cap. Reduce speed egnine load. If the check engine light is blinking or you notice any whaf performance cueck, such as a loss of power, reduce your speed and try to reduce the demands on the envine. For how to use mouse from keyboard, it would be a good idea to stop towing a trailer.
Have the how to cite a video in chicago style checked as soon as possible to prevent expensive damage.
Use built-in diagnostic services, if available. Many modern cars have integrated remote diagnostic capabilities, with the ability to report on trouble codes and schedule a service appointment.
Decoding Dashboard Warning Lights You might have noticed the gallery of icons on your dashboard when you start your car. More From Consumer Reports. Show comments commenting powered by Facebook. Make a Donation Thee Give a Gift.
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Jan 13, · When it runs into an issue that the ECU cannot correct, the check engine light (CEL) starts glowing. The light is typically yellow or orange, and features an image of engine with text telling the driver to check or service the engine or powertrain. The engine computer stores a diagnostic code when the light begins glowing.
A check engine light or malfunction indicator lamp MIL , is a tell-tale that a computerized engine-management system uses to indicate a malfunction. Found on the instrument panel of most automobiles, it usually bears the legend engine ,  check engine , service engine soon , maintenance required , emmiss maint ,  or a pictogram of an engine—and when illuminated, it is typically an amber or red color.
The light generally  has two stages: steady indicating a minor fault and flashing indicating a severe fault. When the MIL is lit, the engine control unit stores a fault code related to the malfunction, which can be retrieved—although in many models this requires the use of a scan tool.
This warning light can indicate almost anything from a loose gas cap to a serious knock in the engine. Some older vehicles had a single indicator labeled "trouble" or "engine"; this was not an MIL, but an " idiot light " meant to indicate serious trouble with the engine low oil pressure, overheating, or charging system problems and an imminent breakdown.
This usage of the "engine" light was discontinued in the mids, to prevent confusion with the MIL. The MIL appeared in the early 80s along with computerized engine controls. When the computer detected a fault, it illuminated the MIL.
The MIL is commonly referred to today as the "check engine light" or the "service engine soon light". Some vehicles manufactured from the late s to mid s have a MIL that illuminates based on the odometer reading, regardless of engine operation.
For example, in several Mazda models, the light will come on at 80, miles , km and remain lit without generating a computer trouble code. This was done in order to remind the driver to change the oxygen sensor. Some American-built — Chrysler Corporation vehicles had a similar odometer-triggered reminder: "Check EGR", which was reset after service at a Chrysler dealership.
The MIL is also illuminated prior to starting the engine, along with other tell-tales on the dashboard, to demonstrate that the lamp is working and not burned out. The lamp will turn off once the car is started if no monitored faults exist. The MIL will also illuminate if the engine has been cranked but failed to start after returning the ignition to "ON. In pre-fuel injection years many cranking attempts were sometimes required to start the car. If the engine fails to start on the second or third attempt then an actual visual check of the engine could be required.
If the engine suddenly stalls or is triggered by an overload, such as on a manual transmission car, the MIL will also illuminate until the engine is started again.
These burn differently from gasoline, and the EFI system may mistakenly interpret the oxygen sensor's readings as being incorrect. Oxygenated gasoline can cause this false triggering in early EFI systems. From Wikipedia, the free encyclopedia. This article has multiple issues. Please help improve it or discuss these issues on the talk page. Learn how and when to remove these template messages. This article needs additional citations for verification.
Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. The examples and perspective in this article may not represent a worldwide view of the subject.
You may improve this article , discuss the issue on the talk page , or create a new article , as appropriate. October Learn how and when to remove this template message. As the name suggests, its purpose was redundancy in case the primary MIL failed. Key Smiths. April 11, Retrieved April 11, How Stuff Works. Retrieved October 27, Archived from the original on October 27, Desert Oasis Auto Repair.
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