Check Engine Light

Your vehicle is equipped with a sophisticated On-Board Diagnostic (OBD) system. This is what has turned on your Check engine light, or MIL (Malfunction Indicator Lamp).

Our technicians at Mike’s Auto Service are well equipped and trained, so that in most cases, they will be able to diagnose and repair problems, quickly and accurately. However, there may be more than one problem “code” appears in your computer.

The OBD system performs a series of ongoing “self-tests” to determine whether all systems are working as designed. Once a failure occurs, subsequent tests are temporarily turned off. This means that once we fix the problem, that caused the original code to set, we may discover other problems that could not be detected until the first problem was solved. This is especially likely if you have been driving with the check engine light (MIL) on for more than a few days.

Some of the OBD self-tests require certain specific conditions to occur before they can be run. Some, for example, may require that the engine not be started for at least eight hours since the last trip, and that when it is started, the outside temperature must be warmer than 15° F. Others require that the fuel tank be between one-half and three-quarters full. Most require that the vehicle be driven for several minutes at a steady speed of more that 50MPH. There are many other requirements for each self-test, and all must be met before those tests will be run. Additionally, some tests must be run more that once before they will register a failure. When it’s not practical for us to keep your car and drive it so extensively we must rely on you to do your normal driving and if the MIL illuminates, to brig=ng the vehicle back for further diagnostics. (Each of the OBD self-tests will run eventually during normal driving.)

When you pick your car up after it has been repaired, your receipt will include the specific codes present in your computer at this time. That way, you can have confidence that any future problems are not related to the same cause.

Frequently asked questions

What is the check engine light?

The technical name is the “malfunction indicator lamp” (MIL). The MIL indicates when the vehicle’s On-Board Diagnostic System (OBD) Computer has a problem.

What does the OBD system computer do?

The OBD system computer performs a series of ongoing “self-test” to determine whether all systems are working as designed in your vehicle.

Can’t you just turn the check engine light off?

The check engine light cannot be turned off. With more than hundreds of potential codes with numerous combinations of failures, it is necessary to connect a computer scanner to the vehicle in order for the technician to read the codes to make the diagnosis and recommend repair.

Why does it take so long to find out what is wrong?

Specific conditions in the vehicle need to occur while the computer scanner performs its diagnostics.  There are many other requirements for each self-test and in some cases some tests must be run more than once before they will register a failure. In other words the technician needs time to correctly diagnose the vehicle accurately.

If you have questions regarding your check engine light please call Mike’s Auto Repair Service at 714-375-3145 today and we’ll set up an appointment.