Resetting the engine light on your Infiniti Q50 doesn’t have to be complicated. This guide walks you through safe, effective methods—from using an OBD2 scanner to manual resets—so you can clear the warning and keep your car running smoothly.
Key Takeaways
- Understand the cause first: Never reset the engine light without diagnosing the underlying issue—ignoring it could lead to serious engine damage.
- Use an OBD2 scanner for accuracy: This tool reads error codes and safely clears the light after repairs are made.
- Battery disconnect is a last resort: While it may reset the light temporarily, it also erases important vehicle data and may not fix the root problem.
- Drive cycle matters: After resetting, complete a proper drive cycle to ensure the vehicle’s computer relearns and confirms no active faults.
- Regular maintenance prevents warnings: Stay on top of oil changes, air filters, and spark plugs to reduce the chance of future engine lights.
- Seek professional help when needed: Complex issues like transmission or catalytic converter problems require expert diagnosis.
- Keep records: Document every reset and repair for future reference and resale value.
How to Reset Engine Light Q50: A Complete Step-by-Step Guide
If you’ve noticed the dreaded “Check Engine” light glowing on your Infiniti Q50’s dashboard, you’re not alone. This warning can pop up for dozens of reasons—some minor, like a loose gas cap, and others more serious, like a failing oxygen sensor or catalytic converter issue. While it’s natural to want to turn that light off as quickly as possible, it’s important to remember that the engine light is your car’s way of saying, “Hey, something needs attention.”
In this comprehensive guide, you’ll learn exactly how to reset the engine light on your Q50—safely, effectively, and without causing further problems. We’ll cover everything from understanding what the light means, diagnosing the issue, choosing the right reset method, and ensuring your car runs smoothly afterward. Whether you’re a DIY enthusiast or just want to be informed before visiting a mechanic, this guide has you covered.
By the end, you’ll know how to use an OBD2 scanner, when to disconnect the battery, and why simply clearing the light without fixing the problem is a bad idea. Let’s get started.
Why Does the Engine Light Come On?
Visual guide about How to Reset Engine Light Q50
Image source: i.ytimg.com
Before you even think about resetting the engine light, it’s crucial to understand why it turned on in the first place. The “Check Engine” light—also known as the Malfunction Indicator Lamp (MIL)—is part of your Q50’s onboard diagnostics system (OBD2). This system constantly monitors engine performance, emissions, and various sensors.
When something goes outside normal operating parameters, the computer stores a diagnostic trouble code (DTC) and illuminates the light. Common causes include:
- A loose or faulty gas cap
- Failing oxygen (O2) sensor
- Mass airflow (MAF) sensor issues
- Spark plug or ignition coil problems
- Catalytic converter inefficiency
- Evaporative emissions system leaks
- Engine misfires
Ignoring the light can lead to reduced fuel efficiency, increased emissions, and even engine damage over time. So, while resetting the light might make your dashboard look cleaner, it won’t fix the problem—unless you address the root cause first.
Tools You’ll Need to Reset the Engine Light
To reset the engine light on your Infiniti Q50, you’ll need a few basic tools. The good news? Most are affordable and easy to use.
OBD2 Scanner (Recommended)
This is the most reliable and professional way to reset the engine light. An OBD2 scanner plugs into your car’s diagnostic port (usually under the dashboard near the steering wheel) and communicates with the vehicle’s computer. It can read trouble codes, explain what they mean, and clear the light once the issue is fixed.
Look for a scanner that supports Infiniti vehicles and offers code definitions—not just generic numbers. Budget models start around $20, while advanced Bluetooth scanners that connect to your smartphone can cost $50–$150.
Basic Hand Tools
If you’re planning to fix the issue yourself—like replacing a gas cap or air filter—you may need a screwdriver, socket wrench, or pliers. Always consult your owner’s manual for specific torque specs and procedures.
Replacement Parts (If Needed)
Depending on the diagnosis, you might need a new gas cap, oxygen sensor, or spark plugs. Buy OEM (Original Equipment Manufacturer) or high-quality aftermarket parts to ensure compatibility and longevity.
Owner’s Manual
Your Q50’s manual contains valuable information about the OBD2 port location, fuse box, and reset procedures. Keep it handy.
Step-by-Step: How to Reset Engine Light Q50 Using an OBD2 Scanner
This is the safest and most accurate method. Follow these steps carefully.
Step 1: Locate the OBD2 Port
The OBD2 port in your Infiniti Q50 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. If you can’t find it, check behind the fuse panel or consult your owner’s manual.
Step 2: Turn Off the Engine
Make sure the engine is completely off before plugging in the scanner. This prevents electrical surges and ensures a clean connection.
Step 3: Plug in the OBD2 Scanner
Insert the scanner’s plug firmly into the OBD2 port. 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—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 Trouble Codes
Follow the scanner’s instructions to retrieve the stored trouble codes. These will appear as alphanumeric codes like P0420 (catalytic converter efficiency) or P0171 (system too lean). Write them down or take a photo for reference.
Step 6: Diagnose the Problem
Use the scanner’s built-in code definitions or search online for what each code means. For example:
- P0455: Large evaporative emissions leak (often a loose gas cap)
- P0300: Random/multiple cylinder misfire
- P0135: O2 sensor heater circuit malfunction
If you’re unsure, consult a repair manual or ask a professional.
Step 7: Fix the Issue
Once you’ve identified the problem, fix it. For example:
- Tighten or replace the gas cap
- Clean or replace the MAF sensor
- Replace faulty spark plugs or ignition coils
- Repair vacuum leaks
Never skip this step. Resetting the light without fixing the issue will only cause it to return—and possibly worsen the problem.
Step 8: Clear the Codes
After the repair, return to the scanner and select the “Clear Codes” or “Erase DTCs” option. Confirm the action when prompted. The scanner will send a signal to the car’s computer to reset the engine light.
Step 9: Verify the Reset
Turn the ignition off, wait 10–15 seconds, then turn it back on. The engine light should be off. If it’s still on, the problem may not be fully resolved, or a new code has been stored.
Step 10: Complete a Drive Cycle
To ensure the vehicle’s computer confirms no active faults, complete a drive cycle. This involves driving under various conditions (city, highway, cold start, etc.) so the OBD2 system can recheck all monitored systems.
A typical Q50 drive cycle includes:
- Cold start (engine off for at least 8 hours)
- Drive at 25–35 mph for 3–5 minutes
- Accelerate to 55–65 mph and cruise for 5–10 minutes
- Decelerate without braking (coast in gear)
- Repeat city and highway driving for 20–30 minutes total
After completing the drive cycle, the engine light should remain off if no issues are detected.
Alternative Method: Disconnecting the Battery
If you don’t have an OBD2 scanner, you can try resetting the engine light by disconnecting the car battery. However, this method is less reliable and comes with risks.
Step 1: Turn Off the Engine and Remove the Key
Ensure the car is off and the key is out of the ignition.
Step 2: Locate the Battery
In the Infiniti Q50, the battery is usually in the engine bay on the driver’s side. Open the hood and identify the positive (+) and negative (−) terminals.
Step 3: Disconnect the Negative Terminal
Use a wrench to loosen the nut on the negative (black) cable. Carefully remove the cable from the terminal and tuck it away so it doesn’t touch metal.
Step 4: Wait 15–30 Minutes
This allows the car’s computer (ECU) to fully discharge and reset. Some recommend pressing the brake pedal a few times to drain residual power.
Step 5: Reconnect the Battery
Reattach the negative cable and tighten the nut securely.
Step 6: Start the Car
Turn the ignition on and start the engine. The engine light may be off temporarily, but if the underlying issue remains, it will likely return.
Important Notes:
- This method may reset other systems, including radio presets, clock, and adaptive transmission settings.
- It does not clear all trouble codes—some are stored in non-volatile memory.
- It’s not a substitute for proper diagnosis and repair.
When to Visit a Mechanic
While many engine light issues can be resolved at home, some problems require professional attention. Visit a certified Infiniti technician if:
- The engine light is flashing (indicates a severe misfire that can damage the catalytic converter)
- You’re unable to diagnose the code
- The problem involves the transmission, fuel system, or internal engine components
- The light returns immediately after reset
- You notice performance issues like rough idle, stalling, or loss of power
A professional mechanic has advanced diagnostic tools and can perform repairs safely and correctly.
Troubleshooting Common Reset Issues
Even after following the steps, you might encounter problems. Here’s how to handle them.
Engine Light Comes Back On
This means the issue wasn’t fully resolved. Recheck the trouble codes and inspect related components. For example, if you replaced the gas cap but the light returns, there may be a deeper evaporative leak.
Scanner Won’t Connect
Ensure the ignition is on, the scanner is compatible, and the OBD2 port is clean and undamaged. Try a different scanner if possible.
Battery Disconnect Didn’t Work
Some modern vehicles require a specific procedure or tool to reset the ECU. Battery disconnect alone may not be sufficient.
Radio or Settings Reset
After a battery disconnect, you may need to reset the radio code (found in your owner’s manual or glove box) and reconfigure settings like seat memory and climate control.
Tips to Prevent Future Engine Light Issues
An ounce of prevention is worth a pound of cure. Keep your Q50 running smoothly with these tips:
- Check the gas cap regularly: Make sure it’s tight after every fill-up.
- Follow the maintenance schedule: Replace spark plugs, air filters, and fluids as recommended.
- Use quality fuel: Avoid cheap or contaminated gasoline.
- Address warning lights promptly: Don’t ignore the engine light—diagnose it early.
- Keep the engine clean: Regularly inspect for leaks, corrosion, or loose connections.
Final Thoughts
Resetting the engine light on your Infiniti Q50 is a straightforward process—but only if you do it the right way. Always start by diagnosing the problem, fix the underlying issue, and then use an OBD2 scanner to clear the codes. Avoid quick fixes like battery disconnection unless absolutely necessary.
Remember, the engine light is there to protect your car. Respecting it means fewer repairs, better performance, and a longer life for your Q50. With the knowledge from this guide, you’re now equipped to handle the warning light confidently and keep your luxury sedan running at its best.