Subaru Outback Check Engine Light Flashing Cruise Control Traction Control

When you are driving a Subaru Outback and the check engine light, cruise control light, and traction control light are all illuminated, it typically means that there is something wrong with your vehicle that needs your attention.

The combination of all three of these lights is often referred to as the “Subaru triangle of death” by some owners due to the seriousness of the potential issues.

In this article, we will provide a detailed explanation of each of these three warning lights, the common causes behind this issue, practical solutions to resolve it, and guidance on how to handle the situation.

By the end of this article, you will have a better understanding of what these warning lights mean and what steps to take when you encounter the ‘Subaru Triangle of Death’.

1: Check Engine Light (CEL):

• The check engine light is a general warning that there is a problem with the engine or the vehicle’s emissions system. It can be triggered by a wide range of issues, from minor to more severe.
• The check engine light monitors various sensors and systems within the engine, including the exhaust, fuel, and ignition systems.

2: Cruise Control Light:

• The flashing cruise control light, in conjunction with the check engine light, is a Subaru-specific feature designed to let you know that the cruise control system is temporarily disabled.
• This is often done to prevent potential engine or safety issues when the check engine light is on.

3: Traction Control Light:

• The traction control system is responsible for helping the vehicle maintain grip and stability while driving, especially in adverse road conditions or during abrupt maneuvers.
• If the traction control light is on, it suggests that there may be an issue with the system’s sensors or components, which could affect the car’s handling and safety.

When all three of these lights are illuminated, it’s essential to understand that the check engine light is likely the root cause of the issue. 

1: Common causes for the check engine light, cruise control light, and traction control light 

Here are some common reasons why these lights might all come on together:

1: Loose or Missing Gas Cap:

• A loose or missing gas cap is a common cause of the check engine light coming on. It can lead to an evaporative emissions system leak.
• The gas cap’s primary function is to seal the fuel system to prevent gasoline vapors from escaping into the atmosphere.
• When the cap is loose or missing, the system detects a leak, triggering the check engine light.
• The flashing cruise control and traction control lights are often a safety measure to prevent using cruise control when there may be fuel system issues, which could be exacerbated by cruise control.

2: Faulty Mass Airflow Sensor (MAF):

• The mass airflow sensor measures the amount of air entering the engine. This data is crucial for the engine control unit (ECU) to adjust the air-fuel mixture.
• A malfunctioning MAF sensor can cause incorrect air-fuel ratios, leading to reduced engine performance and increased emissions.
• The check engine light may illuminate due to this issue. The cruise control and traction control systems may also be disabled to prevent potential issues during reduced engine performance.

3: Faulty Oxygen Sensor:

• Oxygen sensors (O2 sensors) monitor the amount of oxygen in the exhaust gases. This information helps the ECU fine-tune the fuel mixture for optimal combustion and emissions control.
• A failing O2 sensor can result in an incorrect fuel mixture, affecting engine efficiency and emissions.
• The check engine light often activates when an O2 sensor fails. The cruise control and traction control systems may be disabled as a safety precaution.

4: Ignition Problems:

• Ignition problems encompass a range of issues related to the engine’s spark plug and ignition coil system.
• Ignition issues, such as worn-out spark plugs or failing ignition coils, can cause engine misfires and poor combustion, leading to reduced performance and increased emissions.
• The check engine light may come on due to these problems, and the cruise control and traction control systems may be disabled to prevent potentially hazardous situations during poor engine performance.

5: Engine Misfire:

• An engine misfire occurs when one or more cylinders fail to ignite correctly.
• Misfires can result from various issues, including ignition problems, fuel delivery issues, or vacuum leaks.
• The check engine light will illuminate when the ECU detects a misfire because it can lead to increased emissions.
• The cruise control and traction control systems are often disabled when the check engine light is on to prevent dangerous driving conditions due to the potential lack of engine power or stability.

6: Transmission Problems:

• Transmission issues can encompass sensor failures, gear-shifting problems, or fluid-related concerns.
• Malfunctions in the transmission can result in improper power delivery, affecting the overall vehicle performance.
• When the check engine light is triggered by transmission problems, the cruise control and traction control systems may be disabled to prevent unpredictable acceleration or loss of traction, which could lead to safety hazards.

In all cases, when you encounter the check engine light flashing along with disabled cruise control and traction control, it’s essential to address the underlying issue promptly to ensure the safe and efficient operation of your Subaru Outback. If you Ignore these warning lights can potentially lead to more significant and costly problems

1: What are the risks of driving with all three lights illuminated?

Driving with the check engine light, cruise control light, and traction control light on in your Subaru Outback can carry several risks, as these warning lights indicate potential issues that can affect the safety, performance, and emissions of your vehicle. Here are the risks associated with driving when these lights are illuminated:

1.1: Reduced Performance: 

When the check engine light is on, it often indicates an issue with the engine or related systems. This can result in reduced engine performance, including decreased power and acceleration. In some cases, you may experience engine misfires, hesitation, or stalling, which can compromise your ability to control the vehicle safely.

1.2: Decreased Fuel Efficiency: 

Many problems that trigger the check engine light can also lead to decreased fuel efficiency. This means you’ll be using more fuel than usual, increasing your operating costs and environmental impact.

1.3: Emissions Non-Compliance: 

A lit check engine light usually means that your vehicle may not meet emissions standards. Driving in this condition can contribute to higher emissions of pollutants, which can harm the environment and potentially lead to legal issues in areas with strict emissions regulations.

1.4: Safety Risks: 

When the cruise control and traction control lights are on, it’s typically because the vehicle’s control systems have been disabled to prevent potential safety hazards. This can be especially risky in adverse weather conditions, where traction control is vital for maintaining stability, or when using cruise control on highways.

1.5: Unpredictable Handling: 

The traction control system is designed to help you maintain control in slippery or hazardous road conditions. When this system is disabled, your vehicle may not respond as expected when traction is compromised, increasing the risk of skidding, loss of control, or accidents.

1.6: Potentially Costly Repairs: 

Ignoring the warning lights and continuing to drive with unresolved issues can lead to more significant and costly repairs down the road. What might start as a minor problem could escalate into a major engine or transmission issue if left unaddressed?

1.7: Engine Damage:

 Certain issues that trigger the check engine light, like a misfiring engine or overheating, can lead to severe engine damage if not promptly addressed. This could result in a complete engine breakdown, requiring costly repairs or replacement.

1.8: Tow or Stranding Risk:

If the vehicle experiences a severe malfunction while driving, it may leave you stranded on the road, requiring a tow to a repair facility. This can be inconvenient, time-consuming, and costly.

2: What to do if you experience this problem?

• The first thing you should do is check the gas cap to make sure it is tight. If the gas cap is loose or missing, tighten it or replace it and see if the lights go off.
• If the lights are still on, you should take your car to a mechanic to have the trouble codes diagnosed. The mechanic will be able to identify the specific cause of the problem and recommend the necessary repairs.

3: Conclusion

Driving with the check engine light, cruise control light, and traction control light on is not recommended. These lights indicate a problem with the engine or emissions system, which can damage the engine catalytic converter and increase emissions.

If you experience this problem, you should check the gas cap and then take your car to a mechanic to have the trouble codes diagnosed.

If you are unable to get your car to a mechanic right away, you can continue to drive it, but you should be aware of the risks. Avoid driving at high speeds or under heavy loads, and be prepared for the car to stall or have other problems.

4: FAQs

Q: What does it mean when the check engine light and cruise control light are flashing on my Subaru Legacy or Forester?

A: This means that the engine control module (ECM) has detected a serious problem with the engine or emissions system. The cruise control system is disabled when the check engine light is flashing, as it is not safe to use when there is a problem with the engine.

Q: Why is the Subaru Outback brake light flashing along with the check engine light?

A: A flashing brake light in a Subaru Outback, accompanied by the check engine light, often indicates a potential problem with the vehicle’s braking system. This could be related to issues such as low brake fluid, a malfunction in the brake system, or problems with the ABS (Anti-lock Braking System). It’s crucial to have the braking system inspected and repaired promptly for safety reasons.

Q: What should I do if the Subaru brake light is flashing and the check engine light is on?

A: When the brake light is flashing and the check engine light is on in a Subaru, it’s essential to take immediate action. The flashing brake light typically signifies a critical brake system issue. The check engine light may indicate an engine problem. It is very risky to continue driving in this condition. Safely pull over, have the vehicle towed to a repair facility, and avoid further driving until both issues are resolved for your safety.