Why did my check engine light come on out of nowhere?

The light could be a minor issue, such as a faulty gas cap, or it could mean something more serious, such as a misfiring engine. 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.

What are the most common reasons for a check engine light to come on?

Here’s a list of some of the most common check engine warnings:

1. Oxygen sensor (or O2 sensor)
2. Catalytic converter failure.
3. Spark plug or ignition coil failure.
4. Airflow sensor failure.
5. Replace the thermostat.
6. Replace exhaust gas recirculation (EGR) valve and clean all EGR ports.

What causes the Check Engine light to come back on?

A: Disconnecting the battery may reset the Check Engine light in most cars, but the light will come back if the problem is not repaired. Also, the readiness code will be erased, which may prevent your car from completing an OBD-II emissions test.

Is it illegal to reset a check engine light?

Reputable auto shops will not reset a check engine light if the problem is not fixed. To do so would be illegal. This would only be acceptable if it is cleared to complete a diagnostic process to identify a problem. Check engine light being on is a sign that there is a problem with the car.

Where do I find the Check Engine Light code?

Then, press the “read” button on the scanner to access the check engine light code. The code will be a series of letters and numbers. Record all of the codes so you can figure out what they represent and make the necessary repairs to your vehicle.

What does a service engine soon light mean?

It’s what almost every motorist has to go through once in a while: the Check Engine or Service Engine Soon light. If this warning light stays on, it means that your vehicle’s computer has detected a problem that can affect your vehicle’s fuel economy and emissions.

Can a code reader fix a check engine light?

Most code readers will allow you to turn off or reset the check engine light. But this action alone does not actually repair the underlying problem. In many cases, the light will simply come back on later.

What’s the best way to reset a check engine light?

In such a case, it is highly recommended to check the codes with a scanner instead. Switching the ignition on and off is also one method of hard reset without disconnecting batteries. Put the keys in your ignition and turn your ignition on and off consecutively after a second in each step.

Why is my Check Engine light not coming back on?

Then connect the scanner again and read the System Status to see if the “Not Ready” condition is gone for all codes that you had cleared. If the check engine light did not come back on, the system is working properly and your car will pass emissions tests. Your car has not been driven enough after resetting the codes.

What does a malfunction indicator light on a car mean?

In many cases, it means that you’ll be visiting the car dealer to repair the issue and get the light turned off. 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.