Do you have a blinking Check Engine light suddenly appearing on your dashboard, and do you want to know why? You’ve come to the right place, for we have researched this question, and we have the answer for you.
A blinking Check Engine light indicates an emergency with the engine. The most common reason is a bad engine misfire. Additionally, a blinking Check Engine light can also mean any of the following:
- PCM malfunction
- Faulty engine sensors
- Faulty EGR valve
- Exhaust emission issues
Let’s talk more about the other reasons why you could get this signal on your vehicle in the succeeding sections. Learn about what you can do about each of these situations in the sections below.
What is OBD II?
The OBD II, or On-Board Diagnostics, is a system present in all modern cars. It is an electronic system that has diagnostic and reporting capabilities that mechanics can use to identify and resolve problems in a car.
The early versions of OBD will activate a MIL or a malfunction indicator light that tells the driver about a malfunction. However, this MIL doesn’t contain any other information about the issue.
Modern versions of OBD include a standard communications port. The port allows a computer or a scanner to connect to the OBD system to get real-time data and any DTCs or diagnostic trouble codes.
DTCs in modern cars provide information for mechanics to easily identify problems in a vehicle. This allows mechanics to come up with solutions to engine problems quickly.
ECU And OBD
The majority of the issues that the ECU (electronic control unit) can identify have a corresponding DTC. When the ECU determines a problem with the vehicle (through data coming from various sensors), it will send the information to the OBD to store the corresponding DTC in its memory. Modern OBD or OBD II will include some information on each DTC to make it easier to locate and diagnose the problem.
Some of the DTCs also have a corresponding warning light on the dashboard. The ECU will trigger the appropriate light on your dashboard at the same time that it sends the information to the OBD II.
These lights are the same MIL from the early versions of OBD. Only this time, you’d be able to get more information from the OBD II when you plug into it.
The Check Engine Light
The Check Engine light is one of the most enigmatic MIL in your vehicle. It could mean something as simple as a loose fuel tank cap, or it could be as severe as a faulty catalytic converter.
Some car models have two Check Engine light colors. One of the two colors (usually amber) will light up to indicate a less severe problem. The second color (orange or red) will light up for critical engine problems.
Most cars have Check Engine lights that have only one color. These systems use a blinking or steady light to indicate the severity of an issue. A single light is simpler and cheaper to install than having two colors of light.
A steady Check Engine light means that your car has a less severe issue. A blinking Check Engine light means that your car has a critical problem that should be fixed right away.
Some vehicle models will experience a Check Engine light that will turn on, flash for some time, then turn itself off. This is a soft failure. This can come from failing wires.
Why Check Engine light flashes 10 times and then stops?
Here are the different reasons why the Check Engine light will blink and what you can do for each.
What is a misfire?
Your engine needs three things to run—fuel, air, and spark. These three must be present inside the combustion chamber at the right time so that your engine will run smoothly.
Timing is important because the valves of a cylinder should open and close at the precise time. The air and fuel mixture must enter the combustion chamber at the right time, just as the exhaust gases must leave when they need to.
If any of these components miss the correct timing, the combustion of the air and fuel mix will fail.
Spark Plug Misfire
Traditionally, a spark plug is a common cause of engine misfires. Old spark plugs only last less than 12,000 miles. Spark plug failures can come from electrodes wearing out, deposits building up on the electrodes, or the ceramic insulators cracking.
When failing spark plugs fail to produce the spark that will initiate combustion, the cylinder will not be able to produce the power that it should generate.
Modern manufacturing techniques and new spark plug components improve the service life of modern spark plugs. Newer spark plugs can now last for 100,000 miles or more.
Replacing spark plugs regularly prevents this type of misfire.
The fuel delivery can also cause a misfire. If there is no fuel going into the combustion chamber, there will be nothing to mix with air and combust.
One cause of fuel misfires is a clogged fuel filter. Like all filters, a fuel filter captures dirt and debris in the fuel to prevent them from getting to the engine. However, the dirt and debris that it captures will become a blockage for fuel flow.
A blockage in the fuel filter limits the amount of fuel that gets to the engine.
Fuel rails and fuel injectors can also get dirty and clogged. This will also limit the amount of fuel that will get to the combustion chamber and lead to a combustion failure.
Bring your car to a mechanic to clear any blockage in the fuel distribution system.
A mechanical misfire is the most dangerous of the three causes of misfires.
This type of misfire usually originates from the slippage of the timing chain or belt. This causes the opening and closing of the valves to go out of sync.
Worn timing chains and belts have a higher likelihood of slipping or breaking.
The timing chain is lubricated by the engine oil. However, contaminated engine oil can lead to debris getting caught between the links of the timing chain, which causes slippage.
Metal bits in the engine oil are also a sign that it is time to check the timing chain.
Bring your car to a mechanic immediately to check the timing chain or timing belt.
The PCM or the Powertrain Control Module is a computer inside your vehicle that controls the ECM (engine control module) and the TCM (transmission control module). It is responsible for monitoring the temperature of the coolant, the throttle position, and the engine speed. It is also responsible for controlling the timing of fuel injectors, the ignition coils, and the shifting of a modern automatic transmission.
If the PCM starts to fail, you can have problems with the timing of the fuel delivery into the combustion chamber. Similarly, since the PCM is also responsible for the timing of the ignition coils, it decides when to fire up the spark plugs during combustion.
Thus, a failing PCM can cause problems in multiple cylinders at the same time instead of just one or two.
A surge in the electrical circuit can damage the PCM. If this is the case, a professional mechanic can diagnose the problem and do a PCM replacement if necessary.
Faulty Engine Sensors
Many of your vehicle’s modules, like the PCM, rely on sensors to function properly. These modules need information from different sensors in the engine to make decisions on the timing of various functions like injecting fuel or activating the spark plug.
Failing sensors can make it seem like you have a malfunctioning PCM. If the information that the PCM is getting from a faulty sensor is wrong, it will not be able to perform its function correctly. Thus, failing sensors can cause engine misfires.
Unfortunately, sensor diagnosis and replacement are best done by a good mechanic.
Faulty EGR Valve
The EGR valve, or the Exhaust Gas Recirculation Valve, is responsible for regulating the amount of exhaust that goes back to the engine. Too much exhaust going back into the engine can cause the engine to run too lean.
Running lean means that there is too much air and too little fuel inside the combustion chamber. The engine will misfire if there is too little fuel in the combustion chamber.
Thus, a faulty EGR valve can cause a misfire by letting too much exhaust gas into the combustion chamber.
Bring your car to a mechanic to check the EGR valve.
Exhaust Emission Issues
Modern vehicles have complex emissions systems that limit the toxic gases that come out of the exhaust. It helps improve fuel economy by running a healthier engine.
A problem with the components of these systems will trigger the Check Engine light because it can affect the performance of the engine and the fuel economy. It will also cause exhaust to get into the cabin and lead to unpleasant smells that can be a threat to the health of the passengers.
Bring your car to a mechanic to check the components of the exhaust system if you suspect that this is the issue.
A blinking Check Engine light is a sign that there is a critical issue with the vehicle. Bring your car to a mechanic right away.
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