This guide walks you through how to reset the engine light on an Infiniti Q50 using simple methods, including OBD2 scanners, battery disconnection, and built-in diagnostic tools. You’ll save time and money by troubleshooting and clearing check engine lights at home.
Key Takeaways
- Understand why the engine light comes on: It signals issues ranging from loose gas caps to serious engine problems—don’t ignore it.
- Use an OBD2 scanner for accuracy: This is the most reliable way to read and clear error codes on your Infiniti Q50.
- Try the battery reset method: Disconnecting the battery can reset the ECU and clear the light, but may also reset radio and climate settings.
- Check the gas cap first: A loose or faulty gas cap is a common cause and easy fix—always verify before resetting.
- Reset via the dashboard (if supported): Some Q50 models allow manual reset through the trip computer menu—check your owner’s manual.
- Don’t reset without fixing the issue: Clearing the light won’t solve the underlying problem—diagnose first to avoid recurring issues.
- Monitor after reset: If the light returns, visit a mechanic—persistent codes indicate deeper mechanical problems.
Introduction: Why Your Infiniti Q50’s Engine Light Is On
You’re driving your sleek Infiniti Q50 when suddenly—a yellow or orange light appears on your dashboard. It looks like a cartoon engine with a wrench, and it’s labeled “Check Engine.” Your heart sinks. What does it mean? Is it serious? Can you fix it yourself?
The good news? In many cases, yes—you can reset the engine light on your Infiniti Q50 without visiting a dealership or paying a mechanic. But before you hit that reset button, it’s crucial to understand what triggered the light in the first place.
The “Check Engine” light, also known as the Malfunction Indicator Lamp (MIL), is part of your vehicle’s onboard diagnostic system (OBD2). It monitors everything from emissions to fuel efficiency and engine performance. When something goes out of range—like a misfire, oxygen sensor failure, or even a loose gas cap—the computer logs a trouble code and turns on the light.
This guide will walk you through how to reset the engine light on an Infiniti Q50 safely and effectively. We’ll cover multiple methods, from high-tech OBD2 scanners to simple battery resets, and help you decide which one is right for your situation. You’ll also learn how to diagnose the root cause so the light doesn’t come back.
Whether you’re a DIY enthusiast or just trying to save a few bucks, this step-by-step guide will empower you to take control of your vehicle’s health—right from your driveway.
What Causes the Engine Light to Come On?
Visual guide about How to Reset Engine Light on Infiniti Q50
Image source: i.ytimg.com
Before resetting the light, it’s essential to understand why it turned on in the first place. Ignoring the cause and just clearing the code is like turning off a smoke alarm while your house burns down—it doesn’t solve the problem.
Here are the most common reasons the engine light appears on an Infiniti Q50:
1. Loose or Faulty Gas Cap
This is the #1 culprit. A loose, cracked, or missing gas cap allows fuel vapors to escape, triggering an evaporative emissions system (EVAP) code. It’s easy to fix—just tighten or replace the cap.
2. Oxygen (O2) Sensor Failure
O2 sensors monitor exhaust gases and help the engine adjust the air-fuel mixture. A faulty sensor reduces fuel efficiency and increases emissions. Replacing it usually costs $100–$300.
3. Catalytic Converter Issues
A clogged or failing catalytic converter can cause poor performance and high emissions. This is a serious issue that often follows prolonged driving with other unresolved problems.
4. Mass Airflow (MAF) Sensor Problems
The MAF sensor measures how much air enters the engine. If it’s dirty or malfunctioning, your Q50 may hesitate, stall, or run rough.
5. Spark Plug or Ignition Coil Failure
Worn spark plugs or bad coils cause misfires, which trigger the engine light. This is common in high-mileage vehicles and can lead to engine damage if ignored.
6. Exhaust Gas Recirculation (EGR) Valve Issues
A stuck or clogged EGR valve can cause rough idling and increased emissions. Cleaning or replacing it often resolves the issue.
7. Software Glitches or Temporary Sensor Errors
Sometimes, the light comes on due to a temporary glitch—like extreme weather or a brief sensor dropout. These may resolve on their own.
8. Serious Engine or Transmission Problems
In rare cases, the light indicates a major mechanical failure. If the light is flashing (not just steady), pull over immediately—this signals a severe misfire that can damage the catalytic converter.
Understanding the cause helps you choose the right reset method and avoid recurring issues.
Method 1: Using an OBD2 Scanner (Recommended)
The most accurate and reliable way to reset the engine light on your Infiniti Q50 is with an OBD2 (On-Board Diagnostics) scanner. This tool reads the trouble codes stored in your car’s computer, tells you exactly what’s wrong, and allows you to clear the light—all without guessing.
Why Use an OBD2 Scanner?
– Reads specific diagnostic trouble codes (DTCs) like P0420 (catalytic converter efficiency)
– Confirms the issue before resetting
– Prevents clearing the light while a serious problem persists
– Works on all Infiniti Q50 models (2014 and newer)
Step-by-Step: Resetting with an OBD2 Scanner
Follow these steps carefully:
Step 1: Locate the OBD2 Port
The OBD2 port is usually under the dashboard, near the driver’s side footwell. In the Infiniti Q50, it’s typically located below the steering column, slightly to the left. It’s a 16-pin connector—look for a black plastic socket.
Step 2: Plug in the Scanner
Turn off the ignition. Plug the OBD2 scanner into the port. Make sure it’s fully seated.
Step 3: Turn on the Ignition
Turn the key to the “ON” position (but don’t start the engine). This powers up the car’s computer and allows the scanner to communicate with it.
Step 4: Power On the Scanner
Press the power button on your scanner. Most models will automatically detect the vehicle and begin scanning.
Step 5: Read the Trouble Codes
Navigate the menu to “Read Codes” or “Scan.” The scanner will display one or more DTCs (e.g., P0171 – System Too Lean). Write these down or take a photo.
Step 6: Research the Code
Use the scanner’s built-in database or search online (e.g., “P0171 Infiniti Q50”) to understand what the code means. This helps you decide if it’s safe to reset or if repairs are needed.
Step 7: Clear the Codes
Once you’ve addressed the issue (or confirmed it’s minor), go to the “Clear Codes” or “Erase DTCs” option. Confirm the action. The scanner will send a signal to reset the ECU.
Step 8: Turn Off the Ignition
Wait 10–15 seconds, then turn the key back to “OFF.” Unplug the scanner.
Step 9: Start the Engine
Start your Q50. The engine light should be off. If it returns within a few minutes, the problem wasn’t fully resolved.
Recommended OBD2 Scanners for Infiniti Q50
– BlueDriver Bluetooth Scanner: Works with iOS and Android, offers detailed reports, and is highly rated.
– Autel MaxiCOM MK808: Professional-grade, supports advanced diagnostics.
– INNOVA 3160g: Affordable, easy to use, and includes code lookup.
Tip: Many auto parts stores (like AutoZone or O’Reilly) offer free code reading. You can use this to diagnose the issue before buying a scanner.
Method 2: Battery Disconnection (Hard Reset)
If you don’t have an OBD2 scanner, disconnecting the battery is a common alternative. This method resets the Engine Control Unit (ECU) by cutting power, which clears stored codes and turns off the engine light.
How It Works
The ECU stores trouble codes and adaptive learning data (like fuel trim and idle speed). When you disconnect the battery, the ECU loses power and resets to factory settings. This clears the codes—but also resets other systems.
Step-by-Step: Battery Reset on Infiniti Q50
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
Open the hood. The battery is on the right side (passenger side) of the engine bay.
Step 3: Disconnect the Negative Terminal
Use a 10mm wrench to loosen the nut on the negative (black) battery cable. Remove the cable and tuck it away from the battery terminal.
Step 4: Wait 15–30 Minutes
This allows the ECU to fully discharge. Some experts recommend waiting up to an hour for a complete reset.
Step 5: Reconnect the Battery
Reattach the negative cable and tighten the nut securely.
Step 6: Start the Engine
Turn the key and start the car. The engine light should be off. Let the car idle for 5–10 minutes to allow the ECU to relearn basic settings.
What to Expect After a Battery Reset
– Radio presets and clock settings may reset
– Climate control settings may revert to default
– The car may run rough for a few minutes as the ECU relearns
– Some systems (like keyless entry) may need re-syncing
Limitations of the Battery Reset Method
– Doesn’t tell you what caused the light
– May not clear all codes (especially persistent ones)
– Can trigger other warning lights temporarily
– Not recommended for hybrid or high-voltage systems
Use this method only if you’re confident the issue is minor (like a loose gas cap) and you don’t have access to a scanner.
Method 3: Dashboard Reset (If Supported)
Some Infiniti Q50 models allow you to reset the engine light through the trip computer menu—without any tools. This feature isn’t available on all trims or model years, so check your owner’s manual first.
How to Check If Your Q50 Supports Dashboard Reset
– Look for a “Settings” or “Vehicle” menu in the instrument cluster
– See if there’s an option for “Reset MIL” or “Clear DTC”
– Consult the Infiniti owner’s manual (usually available online)
Step-by-Step: Dashboard Reset (If Available)
Step 1: Turn the Ignition to “ON”
Don’t start the engine—just turn the key to the second position.
Step 2: Navigate the Menu
Use the steering wheel controls to access the trip computer. Look for “Settings” > “Vehicle” > “Diagnostics” or similar.
Step 3: Find the Reset Option
If available, select “Clear Codes” or “Reset MIL.” Confirm the action.
Step 4: Turn Off the Ignition
Wait 10 seconds, then turn the key off.
Step 5: Start the Engine
The light should be off. If not, the reset wasn’t successful—try another method.
Note: This method is rare on the Q50. Most models require an OBD2 scanner or battery reset.
Method 4: Drive Cycle Reset (Natural Clearing)
Sometimes, the engine light turns off on its own after the problem is fixed. This is called a “drive cycle reset.” The ECU monitors sensors over time, and if everything checks out, it clears the code automatically.
How a Drive Cycle Works
The ECU runs a series of tests during normal driving. If all systems pass, the light turns off after 3–5 successful drive cycles.
Steps to Complete a Drive Cycle on Infiniti Q50
Step 1: Fix the Underlying Issue
Ensure the problem is resolved (e.g., tighten gas cap, replace sensor).
Step 2: Drive Under Varied Conditions
– Start with a cold engine
– Drive at varying speeds (city and highway)
– Include acceleration, deceleration, and steady cruising
– Let the car idle for a few minutes
Step 3: Repeat for 3–5 Trips
Each trip should last 15–30 minutes. The ECU will retest systems and may clear the code.
When This Method Works Best
– After fixing a minor issue (like a loose gas cap)
– For temporary sensor glitches
– When you don’t have tools or time for a manual reset
Note: This won’t work for serious or persistent problems. If the light stays on, use an OBD2 scanner.
Troubleshooting: What If the Light Comes Back?
You reset the engine light, but it returns within days or weeks. This means the underlying issue wasn’t fixed—or a new one has developed.
Common Reasons the Light Returns
- Unresolved mechanical problem: The code was cleared, but the faulty part wasn’t replaced.
- Intermittent issue: A sensor fails only under certain conditions (e.g., cold weather).
- Multiple problems: One fix revealed another issue the ECU was masking.
- Incorrect reset method: Some methods don’t fully clear persistent codes.
What to Do If the Light Returns
1. Re-scan with an OBD2 scanner: Check for new or recurring codes.
2. Inspect recent repairs: Did you replace a part correctly? Are connections secure?
3. Monitor driving behavior: Note when the light appears (e.g., during acceleration, at idle).
4. Visit a mechanic: If the light persists, professional diagnosis is needed.
When to See a Mechanic
– The light is flashing (indicates severe misfire)
– You hear knocking, stalling, or loss of power
– The light returns immediately after reset
– You’re unsure how to interpret the codes
Don’t ignore a returning engine light—it could signal costly damage.
Prevention Tips: How to Avoid Future Engine Light Issues
An ounce of prevention is worth a pound of cure. Here’s how to keep your Infiniti Q50 running smoothly and avoid unnecessary check engine lights.
1. Regular Maintenance
Follow the scheduled maintenance in your owner’s manual:
– Oil changes every 5,000–7,500 miles
– Replace spark plugs every 60,000–100,000 miles
– Inspect air filters and fuel filters annually
2. Use Quality Fuel
Fill up at reputable stations. Low-quality fuel can cause sensor errors and carbon buildup.
3. Tighten the Gas Cap
After every fill-up, make sure the gas cap clicks 3–5 times. This prevents EVAP leaks.
4. Address Issues Promptly
Don’t delay repairs. A small problem can escalate quickly.
5. Keep the Engine Clean
Regularly clean the MAF sensor and throttle body to prevent contamination.
6. Use a Code Scanner Periodically
Even if the light isn’t on, scanning every 6 months can catch early warnings.
Conclusion: Take Control of Your Infiniti Q50’s Health
Resetting the engine light on your Infiniti Q50 doesn’t have to be intimidating. With the right tools and knowledge, you can diagnose, address, and clear the issue—often without leaving your driveway.
Start by understanding why the light came on. Then choose the best reset method: an OBD2 scanner for accuracy, a battery reset for simplicity, or a drive cycle for minor issues. Always fix the root cause before resetting, and monitor your car afterward.
By following this guide, you’ll save money, reduce stress, and keep your Q50 running at its best. Remember: the engine light is your car’s way of saying, “Hey, check this out.” Listen to it—and take action.
Now go ahead, grab your scanner, and take control of that dashboard light. Your Infiniti Q50 will thank you.