Unlike long ago where check engine light diagnosis had to be done by a mechanic, now it can be done by anyone and not necessarily a mechanic. All you need is some information to know what to check and the right tools for checking the engine.
On board diagnosis is important and will save you a lot of troubles. For most cars that use fuel, the ignition system, fuel injection and automatic transmission is run by a computer. Data is collected from the engine and other parts of the car and the information and commands is sent to the fuel injectors and ignition coils for the cylinders to be fired. The collected data is used to improve the combustion process while making sure that the right amount of gasoline and ignition timing for provision if clean and efficient power and low pollution.
For check light diagnosis, a scan tool is connected to the obd2 connector under the dash. The key can then be turned on but not the engine. On the screen of the tool you will then see many questions being asked that are supposed to be answered such as the VIN, model of the vehicle and the type of engine used by the car. You will then follow the instructions that you will get.
Trouble codes can then be checked among many other menu choices. Depending on the kind of scan tool used, some tools will even go ahead and give you explanation of the codes. There are some scanners that will give you a CD-ROM giving you what the codes mean or a paper pamphlet. The right and sure approach is to check online on the site of your vehicle manufacturer to get the right details on the codes as you may get additional explanation. You will need to know the codes well for setting the MIL indicator. Among the menu options in most scanners you will find inspection and readiness option (I/M). If the MIL had been turned off, drive the car until the PCM confirms the fault has been corrected. The duration of the I/M readiness tests depends on the make of the car.
Most scanners have a menu option of viewing data and here is where you can pin down the main problem. The PCM reading can help you to check essential things like water and air, oxygen sensor function, temperature and engine load among many others potential trouble areas.
With the advanced technology, there are some interfaces and software that will enable you to make a direct connection of the computer and the obd2 through a USB so that you can view all the data through a computer and even make a print out if necessary.
There are many tools that can be used for check engine light. With many websites that are dedicated in the provision of that, you can get a list of all the obdii tools for check engine light. It is however important to know the functionality of each tool to make sure you get one that best suits your needs.