Subaru Outback Check Engine Light Flashing - Common Reasons and Solutions

The Subaru Outback is a versatile vehicle that is popular for its rugged design and all-terrain capabilities. However, like many vehicles, it is prone to developing certain issues that can result in a check engine light. Every driver is familiar with the check engine light, but what does it mean if your Outback's check engine light is flashing?

Flashing check engine light highlights

• Common reasons:error code stored in the ECU
• How to fix:scan for codes
• Possible consequences:engine may fail or stall
• Priority level:High
• Can you drive?Carefully
• DIY repair:Impossible
• Repair price range:$200-$800

What does a flashing check engine light mean?

The check engine light is a crucial part of your vehicle's warning system. Normally the check engine light comes on to inform you of an issue with the engine. However, when the check engine light is flashing, it is an indication that the computer has detected a serious issue with the engine that needs to be attended to as soon as possible.

A flashing check engine light is very serious and requires immediate attention. If the check engine light is flashing, you should stop driving the vehicle as soon as it is safe to do so. Driving with a malfunctioning engine or transmission is unsafe and can cause further damage, or even destruction of parts of the engine.

Common Reasons for Flashing Check Engine Light in Subaru Outback

A blinking check engine light only indicates that the engine is misfiring, but it doesn't indicate the cause of the misfiring. This could be the result of several problems from one of the car's many systems. Knowing the potential causes of a flashing check engine light is the first step to finding a solution.

Some of the common causes of a flashing check engine light are:

• Clogged fuel injectors
• Mass airflow sensor failure
• Faulty fuel pump
• Bad engine valves or damaged pistons
• Faulty ignition coils

The Subaru Outback commonly suffers from some issues that predispose it to engine troubles. These issues can cause a flashing check engine light to come up. Here are some of the common causes of a flashing check engine light in the Subaru Outback.

• Misfiring Engine

A misfiring engine is the most common cause behind most flashing check engine lights. Engine misfiring occurs when the fuel in one of the cylinders undergoes incomplete combustion. This results in unburned fuel escaping the vehicle through the exhaust system.

It is a critical situation for the engine to be in and needs to be resolved quickly to prevent serious damage to the car. It can result in serious damage to the engine and the car. Unburned fuel in the exhaust will quickly raise the temperature of the catalytic converter, which can cause it to suffer severe damage that will require expensive repairs. The catalytic converter could even become hot enough to start a fire.

• Faulty oxygen sensor

Many versions of the Subaru Outback are prone to an issue where the front oxygen sensor cracks. The oxygen sensor measures the level of unburned oxygen in the exhaust and sends that data to the ECU. This allows the car to adjust the fuel mixture and ensure that the proper amount of fuel is being delivered to the engine.

When the oxygen sensor cracks, the car can no longer measure the amount of oxygen in the exhaust. This can result in the engine receiving a lean or rich fuel mixture that can result in the engine misfiring.

• Head Gasket Leak

The Subaru Outback uses an aluminum head to keep the weight of the engine low. While aluminum is a lightweight solution, aluminum heads do not hold up well to heat. If the engine overheats, this could result in the head warping. This can cause the head gasket to fail and start leaking oil.

A head gasket leak will sometimes trigger a flashing check engine light, especially when it results in misfiring.

This problem is much more common for Subaru Outback owners who live in very hot environments. The issue is also compounded by the fact that the Subaru Outback is prone to developing a water pump problem that causes the engine to overheat easily.

• Faulty Sparkplugs

When sparkplugs start to break down or are too dirty, they can fail to generate a spark and ignite the fuel in the cylinders. This can result in misfiring in the engine that triggers a flashing check engine light.

The sparkplugs in the Subaru Outback are difficult to reach and require the removal of some parts of the engine. For this reason, they are often ignored during maintenance, which can result in sparkplug issues.

How to diagnose the cause of a flashing check engine light

Diagnosing the cause of a flashing check engine light in a Subaru Outback is a difficult task because there are many different possible causes. The dashboard gives you no indication of what the problem might be, apart from simply letting you know that there is a problem with the engine.

A diagnostic tool, also known as an OBD2 scanner, can be used to read codes and diagnose the issue. These tools can be purchased online or at an auto parts store, and they are relatively easy to use. Simply connect the tool to the OBD2 port under the dashboard, and it will display the codes that are causing the check engine light to flash.

Once you have the codes that are causing the issue, you can look up the meaning of the codes for Subaru vehicles. This will give you a more definitive idea of where the problem lies and what to look for.

Solutions for a Flashing Check Engine Light

A flashing check engine light needs to be addressed promptly to prevent the vehicle from suffering further damage. Once you have identified any diagnostic trouble codes, you will have an idea of which parts of the engine could be responsible for the issue.

However, the Subaru Outback has a list of specific issues that can bring about a flashing check engine light. Some of these are minor issues, while others can result in serious damage to the engine if left unchecked. Here are some of the problems the Subaru Outback can face that will result in a flashing check engine light. 

1) Replace the Faulty or Cracked Oxygen Sensor

If the oxygen sensor is cracked, it won't be able to carry out its function. In many cases, your car will still run fine with the failed sensor, but if it is causing a flashing check engine light to show up, then it will need to be replaced promptly. Make sure to replace the cracked or faulty oxygen sensor with a more durable version to prevent the same failure from coming up again.

2) Replace Damaged Sparkplugs

If your vehicle is experiencing misfires, one thing you can check is the sparkplugs. To do this, you'll need to disconnect the plug wire going into the sparkplug of the misfiring cylinder. You can use a sparkplug socket to help you remove the spark plug and get a good look at it.

If the sparkplug is too dirty, the electrical resistance in the electrode might be too high to allow it to generate a spark. You can fix this by cleaning the sparkplug with a wire brush. Damaged or failed sparkplugs will also need to be replaced. Make sure that any new sparkplugs are identical to the sparkplugs that are already in the engine.

3) Replace the Damaged Head Gasket and Head

If the flashing check engine light is caused by a head gasket leak, then you will need to have a mechanic take a look at your head gasket. The issue is most likely caused by a warped head, which can also result in damage to the head gasket. Head gasket replacement is a very difficult procedure that is best left to an automotive repair professional.

If the cylinder head is warped, it will need to be reground. If it is cracked or warped too badly, then it might not be possible for a machinist to resurface it. If this is the case, then the head will need to be replaced.

After having the head repaired or replaced, you should consider having the water pump as well. The Subaru Outback suffers from water pump failure that can result in engine overheating. The cylinder head may have failed due to overheating caused by a failed water pump.

Conclusion

In conclusion, the Subaru Outback is a rugged, versatile vehicle that happens to be plagued by a few engine issues that can result in a flashing check engine light. Apart from the usual causes of a flashing check engine light, Outback owners need to be aware of head gasket leakages, warped cylinder heads, cracked oxygen sensors, and faulty water pumps.

A flashing check engine light is usually the result of a misfiring engine, which can cause serious damage to the engine. You cannot afford to ignore it, otherwise, you run the risk of a cracked cylinder head and faulty head gasket, or even the catalytic converter catching fire or exploding.