Question 1

Can I Rent A Check Engine Light Reader?

Accepted Answer

Yes, AutoZone and other auto parts stores offer OBD2 scanner rental services for advanced devices (less advanced devices are usually lent out for free).

Question 2

Can I Take An Emissions Test With An Illuminated Check Engine Light?

Accepted Answer

It’s a smart idea to fix what’s causing the CEL before having a car’s emissions checked. If the issue involves the pollution control system, then the car would fail the testing.

Because modern vehicles have so many interconnected systems, even something as seemingly minor as a clogged mass airflow (MAF) sensor could impact an emissions test.

The emissions/exhaust system is a frequent cause of check engine lights and can cause a car to fail an emissions test quite easily. Don’t waste your time and money, get it fixed first.

Question 3

What Does The Service Engine Soon Light Mean?

Accepted Answer

I can hear the confusion – Why is my service engine soon light on? Is it the same as a check engine light?

A solid “service engine soon” light does not indicate a problem like a solid check engine light does, it typically indicates scheduled maintenance. It’s a reminder to bring your car in for repairs and/or maintenance in the very near future (days or weeks). The message is usually triggered after you’ve driven a certain number of miles or if a set time period has elapsed.

Ok but, why is my service engine soon light blinking?”

You need to take your car in for service immediately, your car is overdue for maintenance (blinking or flashing means urgency).

Question 4

What Is The Most Common Reason For A Check Engine Light?

Accepted Answer

There can be hundreds (if not thousands) of reasons for a check engine light to come on. However, the reason is usually related to emissions, like an oxygen sensor or MAF sensor. Pollution control systems are highly sensitive, and the slightest variation beyond a normal operating condition can trigger a CEL.

Question 5

Does The Check Engine Light Always Mean That There Are Issues?

Accepted Answer

A check engine light indicates the system has detected a DTC code, signaling there’s some type of issue with your engine. While there could be a problem with the diagnostic system itself and not the engine, that is extremely rare. Remember though, just because your engine has an issue doesn’t mean it’s serious, get it checked out. You may find it was just a loose gas cap.

Question 6

What Does It Mean If My Check Engine Light Turns On And Off?

Accepted Answer

An intermittent CEL shows that the problem comes and goes. It’s not an unusual situation and can happen, for example, with fluctuating voltage or a periodic blockage of a sensor. An intermittent light is different from a flashing CEL. A flashing light signals a significant issue requiring you to stop driving, turn off the car, and call a tow truck. Read our section on the meaning of flashing check engine lights for more information, we break down the differences between a solid check engine light vs flashing vs intermittent.

Question 7

How Often Does A Check Engine Light Indicate Serious Problems?

Accepted Answer

There’s no precise formula that details how serious a CEL is. But, know that a flashing check engine light is a sign of a significant problem (meaning don’t drive any further). However, a CEL doesn’t have to flash to warn of a major issue. For instance, a check engine light accompanied by an unusual sound, smell, or vibration is an excellent indicator that it’s time to pull over and get a tow.

Question 8

If The Check Engine Light Is Off, Does That Mean Your Car Is Fine?

Accepted Answer

A check engine is an indicator of detectable issues among monitored engine systems but, some engine issues aren’t detectable by the OBD2 system. Also, not every component in a car is monitored. For example, problems with the suspension won’t appear as a check engine light.

Question 9

Why Would A Check Engine Light Suddenly Disappear?

Accepted Answer

There can be several reasons why a CEL abruptly turns off. The problem may have permanently or temporarily gone away. Or, the code got cleared after several drive cycles (this also means the problem is no longer detectable).

Question 10

Do Check Engine Light Codes Get Stored In The ECU If The Check Engine Light Turns Off On Its Own?

Accepted Answer

Yes. The once-active DTC codes are stored for a mechanic to reference during the diagnostic test process. Stored codes can be cleared with the FIXD app or an OBD2 reader if the problem has been fixed.

Question 11

Should a check engine light come on when the key is turned?

Accepted Answer

It’s normal to see a check engine light flashing when the key is in the on position or for it to be flashing before starting in general. The light appears solid or blinking, then goes off once the engine is running. A check engine light is only a problem if it’s on when the engine is running.

Question 12

Can the check engine light turn off by itself?

Accepted Answer

Yes, the Check Engine Light can turn off by itself if the problem causing it is resolved. Just note that some issues require manually resetting the CEL with an OBD-II scanner.

The car’s onboard diagnostic system continuously monitors its many systems and components. If it detects that the issue has been taken care of, it will turn the CEL off but it can take days or weeks to reset.

The check engine light should clear by the time you drive 30 miles after fixing the car. However, we only suggest driving to reset the light if you have confirmed your car’s issue is minor (like a loose gas cap) in order to prevent damaging your engine. For more serious issues that require a repair, it is best to reset the light after the car is repaired and before you test drive. If there’s something wrong, the light should come back on during a test drive or some time in the first 20-50 miles.

Question 13

Why does my check engine light turn on and off intermittently?

Accepted Answer

Your Check Engine Light might be turning On and Off or flickering (not flashing) for several reasons. It could be a loose or damaged wire or connection in the onboard diagnostic system. Or, a minor fault that only occurs under certain conditions, like when accelerating. The Check Engine Light could also be going on and off due to a bad sensor, spark plug, or filter.

To be clear, the Check Engine Light turning on and off seemingly at random,only under specific conditions, or flickering is different from a flashing light that goes on and off similar to how a turn signal flashes or blinks.

A constant flashing or blinking light indicates a more serious problem. Check out our article “What Your Check Engine Light Means & 13 Possible Reasons It’s On” for more information on flashing lights, on and off lights, and what your car is trying to tell you.

Question 14

Does the check engine light turn off automatically after repair?

Accepted Answer

In most cases, once the problem causing the Check Engine Light has been repaired, it will turn off on its own.

However, how long it takes varies depending on the vehicle and the specific issue that was fixed. It can take days or weeks to clear but it should clear after driving about 30 miles. If the light doesn’t turn off, an OBD-II scanner can be used to reset it manually.

Question 15

Do I need a special tool to turn off my check engine light?

Accepted Answer

You don’t necessarily need a special tool to reset a Check Engine Light, however, an OBD-II scanner like FIXD is the best option. Other methods like turning your car on and off three times, disconnecting and reconnecting the battery, or driving until it turns off, are less reliable and may risk damaging your engine (like driving to reset the light) or risk damaging your car’s onboard computer (like disconnecting and reconnecting the battery.

If you must reset your Check Engine Light without a scanner, the safest option is to turn the car on and off 3 times.

Question 16

Can I disable my check engine light permanently?

Accepted Answer

You should not disable the Check Engine Light permanently. It is a critical part of your car’s onboard diagnostic system designed to alert you of any engine or emissions control system issues.

Disabling a Check Engine Light permanently, for instance, by removing the bulb, will not solve the root cause of the issue. You’ll just be less aware of the problem.

Search results for: Check Engine

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How to Reset Your Check Engine Light | 4 Ways To Clear It (With or Without a Scanner)

What to Do When Your Check Engine Light Comes on

How to Read a Check Engine Light With or Without a Scanner

Where To Get Your Check Engine Light Codes Checked For Free

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