Resetting the check engine light on your Infiniti Q50 can be done manually or with an OBD2 scanner—but only after fixing the underlying issue. This guide walks you through safe, proven methods to clear the light and keep your luxury sedan running smoothly.
Key Takeaways
- Never reset the light without diagnosing the problem first: The check engine light indicates a real issue that needs attention. Ignoring it can lead to costly repairs.
- Use an OBD2 scanner for the most reliable reset: This tool reads error codes and safely clears the light after repairs are made.
- Manual reset methods may not work on newer Q50 models: Vehicles from 2014 onward often require electronic reset due to advanced onboard systems.
- Disconnecting the battery is a last resort: It can reset the light but may also erase radio settings, navigation data, and adaptive transmission learning.
- Monitor the light after reset: If it returns, the issue persists and requires professional diagnosis.
- Regular maintenance prevents future warnings: Follow your Q50’s service schedule to avoid common triggers like loose gas caps or faulty oxygen sensors.
- Use genuine Infiniti parts when replacing components: Aftermarket parts may not meet OEM standards and could trigger the light again.
How to Reset Check Engine Light on Infiniti Q50
If you’ve recently fixed an issue with your Infiniti Q50—like tightening a loose gas cap or replacing a faulty oxygen sensor—you might be wondering how to reset the check engine light. That persistent amber glow on your dashboard can be annoying, but it’s actually your car’s way of saying, “Hey, something’s not right.” Once the problem is resolved, you’ll want to clear that warning so you can drive with confidence.
In this comprehensive guide, you’ll learn everything you need to know about resetting the check engine light on your Infiniti Q50. We’ll cover why the light comes on, the safest and most effective reset methods, and what to do if the light returns. Whether you’re a DIY enthusiast or just want to understand your car better, this step-by-step tutorial will help you take control of your vehicle’s health.
By the end of this guide, you’ll be able to confidently reset the check engine light—without risking damage to your car’s electronics or voiding your warranty. Let’s get started.
Why Does the Check Engine Light Come On?
Visual guide about How to Reset Check Engine Light on Infiniti Q50
Image source: i.ibb.co
Before we dive into resetting the light, it’s important to understand why it illuminated in the first place. The check engine light—also known as the malfunction indicator lamp (MIL)—is part of your Infiniti Q50’s onboard diagnostics system (OBD2). This system continuously monitors engine performance, emissions, and various sensors.
When a problem is detected, the computer stores a diagnostic trouble code (DTC) and triggers the light. Common causes include:
- A loose or missing gas cap
- A failing oxygen (O2) sensor
- A faulty mass airflow (MAF) sensor
- Catalytic converter issues
- Misfiring spark plugs or ignition coils
- Exhaust gas recirculation (EGR) valve problems
- Evaporative emissions system leaks
Some of these issues are minor and easy to fix—like tightening the gas cap. Others may require professional diagnosis and repair. The key point? You should never reset the check engine light without first identifying and addressing the root cause. Resetting it while a problem persists is like turning off a smoke alarm while your kitchen is on fire—it doesn’t solve the issue; it just hides it.
When Should You Reset the Check Engine Light?
You should only reset the check engine light after you’ve:
- Diagnosed the problem using an OBD2 scanner or professional scan tool
- Completed the necessary repairs or replacements
- Verified that the issue is resolved (e.g., the gas cap is securely tightened)
Resetting the light prematurely can lead to:
- Continued engine damage
- Failed emissions tests
- Reduced fuel efficiency
- Increased risk of breakdowns
Think of the check engine light as your car’s early warning system. Respecting it helps you maintain your Q50’s performance, longevity, and resale value.
Tools You’ll Need
Before attempting any reset method, gather the right tools. Here’s what you’ll need:
- OBD2 scanner: A handheld device that plugs into your car’s diagnostic port. Basic models cost $20–$50 and can read and clear codes. Advanced scanners offer live data and system tests.
- Owner’s manual: Your Infiniti Q50 manual contains model-specific instructions and safety warnings.
- Basic tools: Screwdrivers, wrenches, or socket sets if you’re performing repairs (e.g., replacing an O2 sensor).
- Safety gear: Gloves and safety glasses, especially if working under the hood.
- Clean cloth: To wipe down components and connections.
If you don’t own an OBD2 scanner, consider borrowing one from an auto parts store (many offer free code reading) or purchasing a budget-friendly model. It’s a worthwhile investment for any car owner.
Method 1: Using an OBD2 Scanner (Recommended)
The safest and most reliable way to reset the check engine light on your Infiniti Q50 is with an OBD2 scanner. This method ensures the system is properly cleared and allows you to verify that no active codes remain.
Step 1: Locate the OBD2 Port
The OBD2 port is a 16-pin connector usually found under the dashboard on the driver’s side. In the Infiniti Q50, it’s typically located:
- Below the steering column
- Behind a small panel or cover
- Within easy reach (no tools needed to access)
If you can’t find it, consult your owner’s manual or look for a label that says “OBD” or “Diagnostics.”
Step 2: Turn Off the Ignition
Before plugging in the scanner, make sure the ignition is off. This prevents electrical surges and ensures a clean connection.
Step 3: Plug in the OBD2 Scanner
Insert the scanner’s connector into the OBD2 port. Push it in firmly until it clicks into place. Most scanners will power on automatically when connected.
Step 4: Turn the Ignition to “On” (Do Not Start the Engine)
Turn the key to the “ON” position (or press the start button without pressing the brake). This powers up the car’s electronics without starting the engine. The scanner should now communicate with the vehicle’s computer.
Step 5: Read the Diagnostic Trouble Codes (DTCs)
Follow the scanner’s on-screen prompts to read the codes. Most devices will display something like “P0420” or “P0171.” Write down the codes—they tell you exactly what’s wrong.
For example:
- P0420: Catalyst system efficiency below threshold
- P0171: System too lean (bank 1)
- P0455: Large evaporative emission leak
Use the scanner’s built-in code library or search online to understand what each code means. This helps you confirm that the issue has been fixed.
Step 6: Clear the Codes
Once you’ve confirmed the repair is complete, select the “Clear Codes” or “Erase DTCs” option on the scanner. The device will send a command to the car’s computer to reset the check engine light.
Step 7: Turn Off the Ignition and Unplug the Scanner
After clearing the codes, turn the ignition off and unplug the scanner. Wait about 30 seconds before restarting the car.
Step 8: Start the Engine and Check the Dashboard
Start your Infiniti Q50. The check engine light should be off. If it remains off after driving for a few minutes, the reset was successful.
Pro Tip: Some scanners allow you to view “pending codes” or monitor live data (like oxygen sensor readings). Use these features to confirm the repair worked before clearing the light.
Method 2: Disconnecting the Battery (Alternative Method)
If you don’t have an OBD2 scanner, you can try resetting the check engine light by disconnecting the battery. This method forces the car’s computer to reset, but it’s not always reliable—especially on newer Q50 models with advanced electronics.
Warning: Disconnecting the battery can erase:
- Radio presets and anti-theft codes
- Navigation system settings
- Adaptive transmission learning (may cause rough shifting temporarily)
- Climate control preferences
Only use this method if other options aren’t available.
Step 1: Turn Off the Engine and Remove the Key
Ensure the car is completely off. Remove the key or press the start button to turn off all systems.
Step 2: Locate the Battery
In the Infiniti Q50, the battery is located in the engine bay on the driver’s side. It’s housed in a black plastic box with a red positive (+) terminal and a black negative (−) terminal.
Step 3: Disconnect the Negative Terminal
Use a wrench or socket to loosen the nut on the negative (black) battery cable. Carefully remove the cable and tuck it away from the battery terminal so it doesn’t accidentally reconnect.
Step 4: Wait 15–30 Minutes
Leave the battery disconnected for at least 15 minutes. This allows the car’s computer to fully discharge and reset. For a more thorough reset, wait up to 30 minutes.
Step 5: Reconnect the Battery
Reattach the negative cable to the battery terminal and tighten the nut securely. Make sure the connection is tight to avoid electrical issues.
Step 6: Start the Engine
Turn the ignition on and start the car. The check engine light may flash briefly, then turn off. If it stays off, the reset was successful.
Note: If the light returns within a few minutes of driving, the underlying issue hasn’t been fixed—or the reset didn’t take. In that case, use an OBD2 scanner for a more reliable solution.
Method 3: Drive Cycle Reset (For Minor Issues)
In some cases—especially after fixing a loose gas cap—the check engine light may turn off on its own after a few drive cycles. A drive cycle is a series of driving conditions that allow the car’s computer to retest systems and confirm the problem is resolved.
This method works best for:
- Evaporative emissions leaks (e.g., gas cap issues)
- Minor sensor glitches
- Intermittent faults that have cleared
Step 1: Ensure the Repair Is Complete
For example, if the light came on due to a loose gas cap, make sure it’s tightened properly—hand-tight plus a quarter turn.
Step 2: Drive the Car Normally
Drive your Q50 for several days, including:
- City driving (stop-and-go traffic)
- Highway driving (steady speeds above 50 mph)
- Cold starts (letting the engine warm up)
- Deceleration and braking
The computer will run self-tests during these conditions. If no faults are detected, the light may turn off automatically.
Step 3: Monitor the Dashboard
Check the dashboard regularly. If the light remains off after 3–5 days of normal driving, the issue is likely resolved.
Important: This method doesn’t work for serious issues like engine misfires or catalytic converter problems. Always use an OBD2 scanner for those.
Troubleshooting: What If the Light Comes Back On?
Even after a successful reset, the check engine light may return. Here’s what to do:
The Light Returns Immediately
- The problem wasn’t fixed
- A new issue has developed
- The repair was incomplete (e.g., gas cap still loose)
Action: Use an OBD2 scanner to read the new code and diagnose the issue.
The Light Returns After a Few Days
- An intermittent fault is occurring
- A sensor is failing gradually
- The repair didn’t fully resolve the problem
Action: Monitor driving conditions when the light appears. Note any symptoms (rough idle, loss of power, etc.) and consult a mechanic.
The Light Flashes While Driving
- This indicates a severe misfire that can damage the catalytic converter
- Pull over safely and turn off the engine
Action: Do not continue driving. Call a tow truck and have the car inspected immediately.
Preventing Future Check Engine Light Issues
The best way to avoid resetting the check engine light is to prevent it from coming on in the first place. Follow these tips:
- Check the gas cap regularly: Make sure it’s tight after every fill-up. Replace it if it’s cracked or worn.
- Follow the maintenance schedule: Your Q50’s manual outlines when to replace spark plugs, air filters, and other components.
- Use high-quality fuel: Top-tier gasoline with detergent additives helps keep fuel injectors clean.
- Address warning lights promptly: Don’t ignore the check engine light—early diagnosis saves money.
- Use genuine Infiniti parts: OEM parts are designed for your vehicle and reduce the risk of compatibility issues.
Regular maintenance not only prevents check engine light issues but also improves fuel economy, performance, and resale value.
Final Thoughts
Resetting the check engine light on your Infiniti Q50 is a straightforward process—but only after you’ve fixed the underlying problem. The OBD2 scanner method is the most reliable and recommended approach, while battery disconnection should be a last resort. Drive cycle resets work for minor issues but aren’t suitable for serious faults.
Remember: The check engine light is your car’s way of communicating. Respecting it helps you maintain your Q50’s luxury performance and reliability. With the right tools and knowledge, you can keep that dashboard clear and your driving experience smooth.