How to Reset Check Engine Light on Subaru Brz

This guide explains how to reset the check engine light on a Subaru BRZ using simple methods like driving cycles, OBD2 scanners, and battery disconnection. Always diagnose the root cause first to avoid recurring issues.

Key Takeaways

• Diagnose the problem first: Never reset the light without identifying and fixing the underlying issue, such as a loose gas cap or faulty oxygen sensor.
• Use an OBD2 scanner for best results: This is the most reliable and safest method to clear codes and reset the light on your Subaru BRZ.
• Driving cycles can auto-reset the light: After repairs, completing a specific driving pattern may allow the car’s computer to clear the light naturally.
• Battery disconnection is a last resort: While it can reset the light, it also erases radio settings, clock, and learned driving data.
• Monitor after reset: Always check if the light returns—if it does, the problem may still exist and requires further inspection.
• Use genuine or compatible tools: Cheap or incompatible OBD2 scanners may not work properly with Subaru systems.
• Regular maintenance prevents issues: Keeping up with scheduled service reduces the chances of triggering the check engine light.

How to Reset Check Engine Light on Subaru BRZ

Seeing the check engine light pop up on your Subaru BRZ dashboard can be unsettling. It’s a warning that something in your vehicle’s engine or emissions system needs attention. While it’s not always a sign of a serious problem—sometimes it’s as simple as a loose gas cap—it should never be ignored. The good news? Resetting the check engine light on your Subaru BRZ is straightforward, especially if you’ve already addressed the root cause.

In this comprehensive guide, you’ll learn multiple safe and effective ways to reset the check engine light on your Subaru BRZ. We’ll cover everything from using an OBD2 scanner to performing a driving cycle or even disconnecting the battery. You’ll also get practical tips, troubleshooting advice, and important warnings to ensure you don’t make common mistakes. Whether you’re a DIY enthusiast or just want to save a trip to the mechanic, this guide has you covered.

Understanding the Check Engine Light

Before jumping into reset methods, it’s important to understand what the check engine light actually means. Unlike brake or oil warning lights, the check engine light (also known as the Malfunction Indicator Lamp or MIL) is tied to your car’s onboard diagnostic system (OBD2). This system continuously monitors sensors and components related to engine performance, fuel efficiency, and emissions.

When a problem is detected—such as a misfire, faulty oxygen sensor, or evaporative emissions leak—the car’s computer stores a diagnostic trouble code (DTC) and triggers the check engine light. The light can appear as either a steady glow or a flashing signal. A steady light usually indicates a minor issue, while a flashing light suggests a severe problem that could damage the catalytic converter if not addressed immediately.

On the Subaru BRZ, the check engine light is located on the instrument cluster, typically near the speedometer. It looks like a small engine icon or the words “CHECK ENGINE.” Ignoring it, even if the car seems to run fine, can lead to reduced fuel economy, increased emissions, or more serious mechanical damage over time.

That’s why the first step before resetting the light is always diagnosis. You need to know what caused it to come on in the first place. Resetting it without fixing the problem is like turning off a fire alarm while the fire is still burning—it doesn’t solve anything and could make things worse.

Method 1: Use an OBD2 Scanner (Recommended)

The most reliable and recommended way to reset the check engine light on your Subaru BRZ is by using an OBD2 (On-Board Diagnostics, Generation 2) scanner. This tool plugs into your car’s OBD2 port, reads the stored trouble codes, and allows you to clear them—effectively turning off the light.

Step 1: Locate the OBD2 Port

The OBD2 port on the Subaru BRZ is typically located under the dashboard on the driver’s side, near the steering column. It’s a 16-pin connector, usually black or gray, and may be behind a small cover. You don’t need any tools to access it—just reach under the dash and feel for the port. It’s often positioned within easy reach, sometimes even visible when you open the driver’s door.

Step 2: Plug in the OBD2 Scanner

Turn off the ignition, then plug the OBD2 scanner into the port. Make sure it’s securely connected. Most scanners will power on automatically when you turn the key to the “ON” position (without starting the engine). Wait a few seconds for the scanner to initialize and communicate with the car’s computer.

Step 3: Read the Trouble Codes

Once the scanner is ready, follow the on-screen prompts to read the diagnostic trouble codes (DTCs). These codes—like P0420 (catalyst efficiency below threshold) or P0171 (system too lean)—tell you exactly what system or component is malfunctioning. Write down the codes or take a photo for reference. This information is crucial for diagnosing the issue.

Step 4: Clear the Codes

After noting the codes, use the scanner’s menu to select “Clear Codes” or “Erase DTCs.” Confirm the action when prompted. The scanner will send a command to the car’s computer to delete the stored codes and turn off the check engine light. This usually takes a few seconds.

Step 5: Verify the Reset

Turn the ignition off, then back on. Check the dashboard—the check engine light should no longer be illuminated. If it remains off after starting the car and driving for a few minutes, the reset was successful.

Tips for Using an OBD2 Scanner

• Use a scanner compatible with Subaru vehicles. Generic scanners work, but Subaru-specific or enhanced models (like those from BlueDriver or Autel) offer better functionality.
• Some scanners can also display live data, freeze frame data, and readiness monitors—helpful for diagnosing intermittent issues.
• If the light comes back on after clearing, the problem hasn’t been fixed. Re-scan and address the root cause.

Method 2: Complete a Driving Cycle

If you’ve already repaired the issue that triggered the check engine light, your Subaru BRZ may be able to reset the light automatically by completing a specific driving cycle. This process allows the car’s computer to re-test the systems and confirm that everything is working properly.

A driving cycle is a series of driving conditions—such as cold starts, highway speeds, and deceleration—that trigger the onboard diagnostics to run self-checks. Once all monitored systems pass, the computer clears the codes and turns off the light.

Step 1: Ensure Repairs Are Complete

Before starting a driving cycle, make sure the underlying problem has been fixed. For example, if the light came on due to a loose gas cap, tighten it securely. If it was a faulty oxygen sensor, replace it. The driving cycle won’t work if the issue still exists.

Step 2: Follow the Subaru BRZ Driving Cycle

While exact cycles can vary slightly, a typical driving cycle for the Subaru BRZ includes the following steps:

• Cold Start: Start the engine when it’s completely cold (hasn’t been run for at least 8 hours).
• Idle for 2 Minutes: Let the engine idle for about 2 minutes to allow the oxygen sensors to warm up.
• Drive at 30–40 mph: Drive steadily for 3–5 minutes to reach normal operating temperature.
• Accelerate to 55–60 mph: Merge onto a highway or open road and maintain speed for 5–10 minutes.
• Decelerate and Coast: Let off the gas and coast in gear for 2–3 minutes to simulate deceleration monitoring.
• Stop and Idle: Come to a complete stop and idle for 1–2 minutes.
• Repeat if Necessary: Some systems may require multiple cycles. Drive for at least 30–60 minutes total.

Step 3: Check the Light

After completing the driving cycle, park the car and turn off the engine. Wait a few minutes, then restart it. If the check engine light remains off, the reset was successful. If it returns, the issue may still be present, or the cycle wasn’t completed correctly.

Tips for Driving Cycle Success

• Avoid short trips—these don’t allow the computer to complete all tests.
• Use a scan tool to check “readiness monitors” before and after the cycle. All monitors should show “Ready” or “Complete.”
• Weather and traffic can affect the cycle. Choose a safe, open route with minimal stops.

Method 3: Disconnect the Battery (Last Resort)

Disconnecting the car battery is a traditional method to reset the check engine light, but it should only be used as a last resort. While it can clear the codes and turn off the light, it also resets other systems in the car, including the radio presets, clock, seat memory, and adaptive transmission learning.

Step 1: Turn Off the Ignition

Make sure the car is completely off. Remove the key or press the start button to ensure no power is flowing.

Step 2: Locate the Battery

The battery in the Subaru BRZ is located in the trunk, on the right side behind a plastic cover. Open the trunk, remove the cover, and you’ll see the battery terminals.

Step 3: Disconnect the Negative Terminal

Use a wrench (usually 10mm) to loosen the nut on the negative (black) battery terminal. Carefully remove the cable and tuck it away from the battery to prevent accidental contact. Wait at least 15 minutes—this allows the car’s computer to fully discharge and reset.

Step 4: Reconnect the Battery

After waiting, reattach the negative cable and tighten the nut securely. Replace the battery cover and close the trunk.

Step 5: Restart the Car

Turn the ignition on and check the dashboard. The check engine light should be off. Start the engine and let it idle for a few minutes. Note that you may need to reset the radio, clock, and other settings.

Important Warnings

• This method does not fix the underlying problem. If the issue persists, the light will return.
• Some modern Subarus may require a relearn procedure for the transmission or throttle body after battery disconnection.
• Avoid disconnecting the positive terminal unless absolutely necessary—it increases the risk of short circuits.

Troubleshooting Common Issues

Even after following the steps above, you might encounter problems. Here are some common issues and how to resolve them.

Check Engine Light Comes Back On

If the light returns shortly after resetting, the original problem hasn’t been fixed. Use an OBD2 scanner to read the new or recurring codes. Common causes include faulty oxygen sensors, catalytic converter issues, or vacuum leaks. Take the car to a trusted mechanic if you’re unable to diagnose it yourself.

Scanner Won’t Connect

If your OBD2 scanner fails to communicate with the car, check the following:

• Ensure the ignition is in the “ON” position.
• Verify the OBD2 port is clean and undamaged.
• Try a different scanner or update the firmware.
• Check for blown fuses related to the OBD system (usually in the interior fuse box).

Light Flashes After Reset

A flashing check engine light indicates a severe misfire that can damage the catalytic converter. Stop driving immediately and have the car towed to a repair shop. Continuing to drive can cause expensive damage.

Radio or Clock Reset After Battery Disconnect

This is normal. Use your owner’s manual to reset the radio presets and clock. Some BRZ models may require a security code to unlock the radio—check your glove box for a card with the code.

Preventing Future Check Engine Light Issues

The best way to avoid dealing with the check engine light is to prevent it from coming on in the first place. Regular maintenance and good driving habits go a long way.

• Replace the air filter regularly: A clogged air filter can cause lean fuel mixtures and trigger codes.
• Use quality fuel: Low-octane or contaminated fuel can cause knocking and sensor errors.
• Tighten the gas cap after refueling: A loose or damaged cap is one of the most common causes of the light.
• Get scheduled maintenance: Follow the Subaru BRZ maintenance schedule for oil changes, spark plug replacements, and emissions checks.
• Listen for unusual sounds: Knocking, pinging, or rough idling can be early signs of engine problems.

Conclusion

Resetting the check engine light on your Subaru BRZ doesn’t have to be complicated. Whether you use an OBD2 scanner, complete a driving cycle, or disconnect the battery, the key is to always address the root cause first. Ignoring the problem won’t make it go away—it could lead to bigger, more expensive repairs down the road.

The OBD2 scanner method is the most effective and recommended approach, giving you precise diagnostic information and a clean reset. Driving cycles are a great free option if you’ve already fixed the issue, while battery disconnection should only be used when other methods aren’t available.

Remember, the check engine light is your car’s way of saying, “Hey, something’s not right.” Treat it with respect, and your Subaru BRZ will continue to deliver the thrilling, reliable performance you love. With the knowledge from this guide, you’re now equipped to handle the light confidently and keep your BRZ running smoothly for years to come.