What does it mean if a check engine light turns off on its own? (2024)

What does it mean if a check engine light turns off on its own?

If your check engine light comes on but turns off randomly, it's a sign you have a minor issue that comes and goes and is tripping the system. A check engine light that's flashing can be a sign of a serious issue with your vehicle's engine and usually requires immediate attention.

Why would a check engine light go off by itself?

In most cases, successfully repairing the issue that caused your light to come on will cause the check engine light to turn off automatically—but only after 10 to 20 “cycles”. A cycle, in this instance, refers to the process of turning the vehicle on, running it for some time, and turning it off again.

Why does my check engine light appear and disappear?

The computer is looking for problems all the while the engine is running, and will turn the CEL on when it detects a problem, and off when it doesn't. At what point in the driving cycle those occur vary from code to code.

Why is my check engine light blinking then disappears?

Intermittent: The check engine light blinks for a while and then turns off by itself. This indicates a possible soft failure. It can be an issue with the car's wiring being cut or constantly being disconnected. Continuous Flashing: If the check engine light is constantly flashing, this indicates an emergency.

Can a check engine light burn out?

If the check engine light does not illuminate during the bulb check, a burned out check engine light bulb or system tampering is indicated.

Can a check engine light mean oil change?

An illuminated check engine light is the first warning sign that your vehicle needs an oil change. It can activate because the oil is too dirty or when there's not enough flowing throughout the engine.

Will disconnecting battery make check engine light go off?

3) Disconnect the Battery then Reconnect

Ideally, this will clear the data, turning off the light.

Do pending codes clear themselves?

These codes are referred to as pending or maturing codes. Pending codes are caused by intermittent faults or faults that the PCM needs to see happen in two consecutive warm-up cycles to set the code. If the fault does not reappear within 40 warm-up cycles, the code will be cleared from memory.

How many miles can you drive with a blinking check engine light?

There is no set time limit, as the severity of the problem can vary. However, it is generally not advisable to drive for more than a few miles with a flashing check engine light. If possible, have the vehicle towed to a repair facility rather than driving it so that you do not put yourself or others at risk.

What is the most common cause of a flashing check engine light?

A failed O2 sensor is the most common cause of a flashing check engine light. The O2 sensor is a critical part of the exhaust system, monitoring how much unburned oxygen is exiting the engine in the exhaust. The sensor sends messages back to the engine to adjust the mix of oxygen and fuel being used.

Will bad spark plugs cause check engine light to flash?

Worn/failed spark plugs, coil packs, or spark plug wires can trigger your check engine light to come on. In today's cars, if a spark plug fails and can no longer ignite the air-fuel mixture, then the most obvious event should be the check engine light coming on or even flashing.

Should I freak out if my check engine light is on?

The best course of action is to not panic, but not to ignore the light, either. Head to your repair shop or call and make an appointment. One exception? If the light flashes on and off, this could be a sign something is seriously wrong.

How do I know if my check engine light is working properly?

To determine if the check engine light is working, you can turn the key onto the run position, there is no need to start the vehicle and this will illuminate the whole gauge cluster showing the functioning lights. If your light does not illuminate, it is either burnt out or someone has removed it.

Can AutoZone check check engine light?

Free Fix Finder Service from AutoZone

Fix Finder reads Check Engine, ABS, and maintenance lights. The free test takes less than a minute and you'll get an easy to understand report printed and emailed. If you need help with the fix, Fix Finder will even recommend a trusted local shop.

Can too much oil cause the check engine light to come on?

If the engine is running rough or your check engine light illuminates, the cause may be excess oil contacting the spark plugs and causing a misfire.

Will check engine light come on for low tire pressure?

Another common cause for a check engine light to come on is low tire pressure. Not all vehicle's are designed with a malfunctioning indicator lamp that will detect this issue, but most newer models do. Simply tend to your tire as needed, and the check engine light will turn off.

Can AutoZone reset check engine light?

AutoZone can help you diagnose the cause of the light and help you correct it. In most cases disconnecting the battery for a few minutes then reconnecting will clear the fault codes and turn off the light. But if the issue has not been resolved it will come back on, in some cases almost immediately.

How do I clear my engine code?

Plug an OBD-II scanner into your vehicle's OBD port and reset it to clear the check engine light. Disconnecting and reconnecting your battery will restart your vehicle's computer and clear the light. Drive an older vehicle around for a few days after repairs. The light will go off on its own once the computer resets.

How do you check engine light codes without a scanner?

What is a stored check engine light?

If a test initially fails during a current drive cycle, a pending DTC associated with the test is set. If the same test fails during the next subsequent drive cycle when the test is run, the Malfunction Indicator Lamp (MIL) is commanded on and a confirmed (stored) DTC is set indicating the faulty component or system.

How long is a drive cycle?

15 minutes of steady driving on an expressway/highway followed by 20 minutes of stop-and-go driving with at least four 30-second idle periods. Allow the vehicle to sit for at least eight hours without starting the engine. Then, start the engine and complete the above driving cycle.

How long do you have to drive after clearing codes?

On clearing the codes with the “Erase Codes” function, the system status changes to “Not Ready”. Drive for 50 to 100 miles (80 to 160 km). Take several individual trips until the system reads the status of all the components once more. “Several trips” means you shut off the engine and start another trip each time.

Can bad gas cause a flashing check engine light?

If you have a tank of bad gas in the car, your check engine light may come on. For example, if your vehicle is designed to run on premium gas (octane grade 91 to 94), the engine may struggle to run on regular gas (octane level 87). You can safely solve this problem by having a professional drain your gas tank.

What does an orange check engine light mean?

A flashing orange light means that there is a problem that could affect how the car drives or handles, such as an engine misfire. You might be able to feel your car shake, or the engine could suddenly sound different. If this light comes on, you should take your car to be inspected immediately.

Why is my check engine light flashing and my car shaking?

A blinking Check Engine light means there's something seriously wrong with the emissions system. The shaking suggests you're having a misfire, which is dumping unburnt fuel into the exhaust, while making the engine shake. This is usually caused by a bad spark plug, ignition coil, or wiring.