What is the most common cause of flashing a check engine light?
The most common cause of a flashing check engine light is a problem with the vehicle's ignition system, specifically the spark plugs or ignition coils. When these components malfunction, it can cause the engine to misfire, leading to the check engine light flashing on the dashboard.
Understanding the Check Engine Light
The check engine light, also known as the malfunction indicator light (MIL), is a warning system in modern vehicles that alerts the driver to potential issues with the engine or other critical components. When the check engine light is illuminated, it indicates that the vehicle's onboard diagnostic system has detected a problem and stored a diagnostic trouble code (DTC).
The check engine light can either be steady or flashing, and the difference between the two is significant. A steady check engine light typically indicates a less severe problem, while a flashing check engine light signifies a more serious issue that requires immediate attention.
Causes of a Flashing Check Engine Light
While a flashing check engine light can have several potential causes, the most common is a problem with the vehicle's ignition system. This includes issues with the spark plugs, ignition coils, or the ignition control module.
Spark Plug Issues
- Worn or damaged spark plugs can cause misfiring, leading to a flashing check engine light.
- Incorrect spark plug gap or type can also contribute to ignition system problems.
When spark plugs are not functioning properly, it can cause the engine to misfire, which in turn can damage the catalytic converter and other components. This is a serious issue that should be addressed promptly.
Ignition Coil Malfunctions
- Faulty ignition coils can also cause engine misfiring, leading to a flashing check engine light.
- Ignition coils are responsible for providing the high-voltage spark to the spark plugs, and if they fail, the engine will not run properly.
Ignition coil issues are another common cause of a flashing check engine light, and they should be diagnosed and repaired as soon as possible to prevent further damage to the engine and other components.
Ignition Control Module Failures
- The ignition control module is responsible for controlling the timing and firing of the spark plugs.
- If the ignition control module malfunctions, it can cause the engine to misfire, leading to a flashing check engine light.
While less common than spark plug or ignition coil issues, a problem with the ignition control module can also trigger a flashing check engine light and should be addressed by a qualified mechanic.
Addressing a Flashing Check Engine Light
If you notice your check engine light is flashing, it's important to have the vehicle diagnosed and repaired as soon as possible. Ignoring a flashing check engine light can lead to further damage to the engine and other components, which can be costly to repair.
The best course of action is to take the vehicle to a qualified mechanic or use a diagnostic tool to read the trouble codes stored in the vehicle's computer. This will help identify the specific issue causing the flashing check engine light, allowing the mechanic to make the necessary repairs.
Can I drive 20 miles with flashing check engine light?
The rule of thumb is that if the check engine light is flashing, you can't keep driving the car. It's an emergency. Often it indicates an engine misfire. If you keep driving, you will likely cause irreversible damage, mostly to the (expensive) catalytic converter.
How much does it cost to fix a flashing check engine light?
Diagnostic fees alone can range from $50 to $200, while repairs can cost anywhere from a few dollars for a loose gas cap to several thousand dollars for more complex problems. If you find yourself facing a check engine light, it's important not to ignore it.
What is the first thing to check when the check engine light comes on?
Check your gas cap first. Many vehicles have a loose gas cap indicator that will be triggered before your check engine light comes on. If your gas cap is loose or the seal is not tight, the vapor leakage can cause your fuel system to trigger the check engine light.
Does AutoZone do free scans?
Visit Your Local AutoZone Store for Free Fix Finder Service
You'll receive both a printed and digital copy of the report for your convenience.
How do you fix a blinking check engine light?
Locate the negative battery cable, which is usually located under the hood of your vehicle. Disconnect the negative battery cable from the battery terminal. Wait for at least 30 seconds before reconnecting the cable. Once you have reconnected the cable, the check engine light should be reset.
What does it mean when your check engine light flashes and then goes off?
A flashing check engine light that periodically disappears indicates a potentially serious problem with your car. It may be something minor, but it's an issue that needs investigation fast. Often, this is a wiring problem, but it can also be triggered by a misfire problem or issues with your vehicle's emissions system.
Will bad spark plugs make the check engine light flash?
Yes, spark plugs can cause a blinking check engine light. A blinking or flashing check engine light typically indicates a severe issue, such as an engine misfire. This can occur when spark plugs are worn out, fouled, or not functioning properly, leading to incomplete combustion in one or more cylinders.
Is it better to have a solid or flashing check engine light?
If your check engine light is flashing, you should not be driving. That means there is imminent catastrophic damage about to occur or already occurring if it's a solid check engine light and it's yellow. It means service engine soon. If it's red, it means have it checked if it's flashing, it means stop and shut off.
Can I drive my car with the check engine light blinking?
If the engine light is flashing, it's best to stop driving as soon as it's safe to do so. Continuing to drive can cause further damage to the engine or other components, leading to more expensive repairs. In general, you should: Pull Over Safely: Find a safe place to stop as soon as possible.
How do you know if you have a bad ignition coil or spark plugs?
When a failing ignition coil prevents a spark plug from sparking, the cylinder begins to misfire. This causes the engine to cough, sputter, and shake as it struggles to keep going. The slower you drive, the worse these symptoms of misfiring are likely to become.
