Disconnecting check engine lights

Unfortunately disconnecting check engine lights is against the law. The federal government in compliance with the clean air act has integrated this check engine light into the vehicle's computer system via hardwired components and communication modules.

When disconnecting check engine lights, you also are disabling the bulb check function. The bulb check function is when the bulb is illuminated, behind the check engine light symbol when the key is turned on and the engine is not running.

Most areas have state inspections or smog check points that verify the proper operation of this check engine light bulb check. If you have disconnected the check engine light, you will be in violation of the clean air act and will fail your state inspection.

The first step in the diagnostic procedure in most cases is clearing the code and see if it returns. Often an intermittent problem will trigger the light and it will stay on until you clear it.

This Autel Maxi scan I have on the left is the cheapest way of clearing codes that I have seen. I do not own this device but the reviews state it works as advertised. I recommend before you clear the codes that you write the 5 digit numbers down. This way if the check engine light comes back on you can see if it is the same code.

Disabling the check engine light would require you to disassemble the dash and remove the bulb. On most late model vehicles, this is a difficult task to complete.

Also on some models when you remove the check engine light bulb, your computer that handles the air fuel mixture will go into a backup mode.

This will cause poor gas mileage and poor drive ability. In essence your computer is monitoring the proper operation of the check engine light and its bulb. The technical term used to describe the check engine light bulb is the MIL or malfunction indicator lamp.

Do not disconnect the check engine light

Over-riding this indicator light is not only against the law, it is counter productive to your vehicle's long-term health. Learning to fix your own check engine light malfunction can be a very rewarding experience.

On this website I supply lots of good information on how to accomplish this repair. Please visit my reset check engine light information page for valuable inside tips on how to retrieve the failure code and repair the problem quickly and easily.

Also visit my DIY auto repair page for online auto repair tips for bringing professional results home to your driveway.

I have learned over the years that when you try to cheat the system, You wind up putting in more time and effort then if you properly fix the auto repair problem in the first place.

Disconnecting check engine lights

It is against the law too not only disconnect your check engine light but to modify any part of its computerized emission system. Help improve the quality of our air and keep your vehicle running as per its design intent.

If you can afford a little more then the $40 it takes to buy the Autel Maxiscan mentioned above I would recommend taking a look at the Equus 3130 scan tool. This scanner will give you room to grow and has many advanced features.

You can read the Data stream and monitor conditions at the time of the fault with a built in snap shot mode. The only feature this auto scan tool is missing is a back lit screen. But the price is unbeatable for the features and diagnostic capabilities included.


Give this disconnecting check engine lights resource page a


This next link takes you to one of the most popular pages on this site. Learn about the best way to turn off check engine lights and the most common cause for the light to come on. Go from Disconnecting check engine lights to Diy auto scan tool page


Use the same tool I do for diagnosis and repair of check engine lights.

More information about the All-data service manuals including a video of how to fix cars with it is available from this next link. See why this thing is the leading online auto repair manuals program.


Need fast answers to your engine light questions?

Ask Your Car Questions

Type your car question here.

 letters left

Custom Search