What is the engine management light? What does it mean?

Depending on your vehicle you will get the message 'engine service soon' or a small clock icon or perhaps a number of green bars.
These are self explanatory and are to let you know that a service is soon due.
This is built into your vehicle to help you maintain it in the best condition. On board diagnostics (OBD ) was introduced in US to help maintain vehicles and keep environmental pollution to a minimum. EOBD simply means European on board diagnostics, the EU equivalent of the American system.

##check engine light = there is a fault in your car's system. details of the fault will be recorder in the ecu. details of the fault can be read from the ecu with a plug in trouble code reader

What is  the 'check engine light'?
How can you solve the problem when the engine light comes on?
The 'check engine light is different to the engine management light. It indicates when something is wrong, a malfunction in one, or more, of the sensors and meters sending information to the car's brain - the ECU.

If the 'check engine' light comes on it sometimes means a fault and your vehicle enters into a "limp mode" .
This means it is running in a 'safe' mode – a program which means more fuel consumption and increased emissions.

To turn off the 'check engine light' you will need first of all to read the fault code to find out what is wrong. When you know the fault,  you can put it right,  reset the codes and have the 'check engine light' switched off.

Let's take an example.
After the check engine light comes on you locate the data link connector (DLC) . It is placed under the dash in the passenger footwell on your particular car and is a 'D' shaped female plug with 16 pin-outs. When you connect a code reader to this data link connector  it automatically turns on and gives you a Diagnostic trouble code (DTC). Let us suppose for the purpose of illustrating the problem that the code is P0100.
We look this code up in a table and find it is a  Mass or Volume Air flow circuit malfunction. On further examination we find that  code P0100 may mean that one or more of the following has happened:
The Mass Air Flow meter (MAF) may be disconnected, or a wiring connection may be bad or the MAF sensor may be faulty. You are now in a position to make checks, put the problem right and reset the code. If everything is OK your car will return to normal running.

Strategy number three
How do you get to read the error code? Reading the error code.

The basic answer to this is you use a code reader. Fortunately all code readers will read Diagnostic trouble codes(DTC).  Code readers can be simple – ones that read Diagnostic trouble codes, - and they can be more complicated (and more expensive). 'only the better ones will read ABS, Transmission codes and reset engine service lights.' If you want a code reader that is multi-purpose and covers every vehicle you will have to pay top dollar.  When you plug in your scanner it will automatically turn on and should give you instructions to show you how to retrieve the trouble code. As soon as you have the code you can interpret it from the chart (supplied with your code reader) or look it up in your Workshop manual or go online and find the code details there. (there are many excellent websites )

Strategy number four

How do you use the code reader? Where do you plug it in?
The scanner plugs into the Data Terminal Connector (DTC) usually located in the driver or passenger foot-well. These data terminal connectors are also called data link connectors. They are located in a variety of different places on different vehicles; have a quick look under the dash, or in the passenger foot-well. It can also be located in the center console, sometimes behind a plastic cover. Your owner's instruction manual should have more information.