Resetting the check engine light on your Infiniti FX35 doesn’t have to be complicated. This guide walks you through simple methods—from using an OBD2 scanner to driving cycles—so you can clear the warning and confirm repairs. Always diagnose the root cause first to avoid recurring issues.
Key Takeaways
- Diagnose the problem first: Never reset the check engine light without identifying and fixing the underlying issue. Use an OBD2 scanner to read trouble codes.
- Use an OBD2 scanner for the safest reset: This is the most reliable and recommended method. It allows you to read codes, clear them, and verify the fix.
- Battery disconnection is a temporary fix: Disconnecting the battery can reset the light, but it may also erase important vehicle settings and won’t work if the issue persists.
- Drive cycles may clear the light automatically: After repairs, driving your FX35 under normal conditions can allow the onboard computer to pass emissions tests and turn off the light.
- Check gas cap first: A loose or faulty gas cap is a common cause of the check engine light. Tighten or replace it before trying other fixes.
- Use genuine parts when replacing components: Aftermarket parts may not meet Infiniti’s specifications and could trigger the light again.
- Monitor the light after reset: If the light returns, the problem wasn’t fully resolved. Recheck codes and consult a mechanic if needed.
How to Reset Check Engine Light on Infiniti FX35
If you’ve noticed the dreaded check engine light glowing on your Infiniti FX35’s dashboard, don’t panic—it happens to the best of us. Whether you’ve just fixed a minor issue like a loose gas cap or completed a more complex repair, you’re probably wondering how to reset that persistent warning light. The good news? Resetting the check engine light on your Infiniti FX35 is simpler than you might think, especially with the right tools and knowledge.
In this comprehensive guide, you’ll learn multiple proven methods to reset the check engine light on your Infiniti FX35. We’ll cover everything from using an OBD2 scanner—the most reliable and recommended approach—to alternative techniques like disconnecting the battery or relying on drive cycles. You’ll also discover essential troubleshooting tips, common causes of the check engine light, and how to avoid recurring problems. By the end of this guide, you’ll have the confidence and know-how to handle this common automotive issue like a pro.
Understanding the Check Engine Light
Before jumping into reset methods, it’s important to understand what the check engine light actually means. Unlike a low fuel warning or door ajar alert, the check engine light—also known as the Malfunction Indicator Lamp (MIL)—is tied directly to your vehicle’s onboard diagnostics system (OBD2). This system constantly monitors engine performance, emissions, and other critical systems.
Visual guide about How to Reset Check Engine Light on Infiniti Fx35
Image source: dealerinspire-image-library-prod.s3.us-east-1.amazonaws.com
When the OBD2 system detects a problem—such as a misfire, faulty oxygen sensor, or emissions leak—it triggers the check engine light and stores a diagnostic trouble code (DTC). These codes are standardized across all vehicles, making it easier for mechanics and DIYers to pinpoint issues.
On the Infiniti FX35, which was produced from 2003 to 2013, the OBD2 system is fully integrated and highly sensitive. That means even minor issues can trigger the light. While some problems are harmless (like a loose gas cap), others can affect performance, fuel economy, or emissions. That’s why it’s crucial to diagnose the root cause before resetting the light.
Common Causes of the Check Engine Light on Infiniti FX35
Here are some of the most frequent reasons the check engine light comes on in the Infiniti FX35:
- Loose or faulty gas cap: This is the number one cause. A loose cap allows fuel vapors to escape, triggering an evaporative emissions code (P0455 or P0457).
- Oxygen (O2) sensor failure: The FX35 has multiple O2 sensors that monitor exhaust gases. A faulty sensor can reduce fuel efficiency and increase emissions.
- Mass Airflow (MAF) sensor issues: This sensor measures incoming air for the engine. Dirt or damage can cause poor performance and trigger codes like P0101 or P0102.
- Catalytic converter problems: Over time, the catalytic converter can become clogged or fail, leading to reduced performance and emissions codes (P0420).
- Spark plug or ignition coil failure: Misfires (codes P0300–P0306) are common in high-mileage FX35s and can damage the catalytic converter if ignored.
- Evaporative emissions system leaks: Small leaks in the EVAP system can trigger codes like P0442 or P0456.
Knowing these common causes can help you narrow down the issue before resetting the light. Always start with a diagnostic scan to confirm what’s wrong.
Method 1: Using an OBD2 Scanner (Recommended)
The safest, most effective way to reset the check engine light on your Infiniti FX35 is by using an OBD2 scanner. This handheld device plugs into your vehicle’s diagnostic port and communicates with the onboard computer. It reads trouble codes, displays real-time data, and allows you to clear the check engine light—all without disconnecting any components.
Step 1: Locate the OBD2 Port
The OBD2 port on the Infiniti FX35 is located under the dashboard on the driver’s side. To find it:
- Sit in the driver’s seat and look down near the steering column.
- The port is usually about 6–8 inches below the wheel, behind a small panel or directly exposed.
- It’s a 16-pin trapezoidal connector—easy to spot once you know where to look.
If you can’t find it, consult your owner’s manual or look for a small cover labeled “OBD” or “DIAG.”
Step 2: Plug in the OBD2 Scanner
Once you’ve located the port:
- Turn the ignition to the “ON” position (but don’t start the engine).
- Plug the OBD2 scanner into the port. Make sure it’s fully seated.
- Wait for the scanner to power on and establish a connection with the vehicle’s computer.
Most modern scanners will display a menu or automatically begin scanning for codes.
Step 3: Read the Trouble Codes
Before clearing the light, always read the trouble codes. This tells you what’s causing the issue and helps you confirm that the problem has been fixed.
- On the scanner, select “Read Codes” or “Scan for DTCs.”
- The device will display one or more codes (e.g., P0420, P0135).
- Write down the codes or take a photo for reference.
Use a free online code lookup tool or the scanner’s built-in database to interpret the codes. For example, P0420 typically means “Catalyst System Efficiency Below Threshold,” which often points to a failing catalytic converter.
Step 4: Fix the Underlying Issue
Now that you know what’s wrong, it’s time to fix it. Depending on the code, this could involve:
- Tightening or replacing the gas cap.
- Cleaning or replacing the MAF sensor.
- Replacing a faulty O2 sensor or spark plug.
- Repairing an EVAP system leak.
Always use high-quality or OEM (Original Equipment Manufacturer) parts when replacing components. Cheap aftermarket parts may not meet Infiniti’s standards and could cause the light to return.
Step 5: Clear the Check Engine Light
After the repair is complete:
- Return to the OBD2 scanner menu.
- Select “Clear Codes” or “Erase DTCs.”
- Confirm the action when prompted.
The scanner will send a command to the vehicle’s computer to reset the check engine light. You should see a confirmation message like “Codes Cleared” or “Reset Successful.”
Step 6: Verify the Reset
Turn the ignition off, wait 10 seconds, then turn it back on. The check engine light should be off. If it remains on, either the issue wasn’t fully resolved, or the vehicle hasn’t completed its self-tests yet.
Some systems require a drive cycle to confirm the repair. We’ll cover that in a later section.
Tips for Using an OBD2 Scanner
- Choose a scanner with live data and code definitions. Basic $20 models work, but advanced scanners offer more features.
- Keep the scanner updated. Some models allow firmware updates via USB or Bluetooth.
- Store the scanner in your glove box for emergencies.
- If you don’t own one, many auto parts stores (like AutoZone or O’Reilly) offer free code reading and clearing services.
Method 2: Disconnecting the Battery
If you don’t have an OBD2 scanner, disconnecting the battery is a common alternative. This method resets the vehicle’s computer by cutting power, which clears stored codes and turns off the check engine light. However, it’s not always reliable and comes with drawbacks.
Step 1: Turn Off the Engine and Accessories
Before touching the battery:
- Turn off the engine and remove the key.
- Turn off all accessories (lights, radio, A/C).
- Ensure the vehicle is in Park (for automatics) or Neutral (for manuals) with the parking brake engaged.
Step 2: Locate the Battery
The Infiniti FX35’s battery is located in the engine bay on the driver’s side. It’s housed in a black plastic case with a red positive (+) terminal and a black negative (−) terminal.
Step 3: Disconnect the Negative Terminal
Always disconnect the negative terminal first to avoid short circuits:
- Use a 10mm wrench or socket to loosen the nut on the negative terminal.
- Carefully lift the cable off the terminal and secure it away from the battery.
- Wait at least 15 minutes. This allows the vehicle’s computer to fully reset.
Some sources recommend waiting up to 30 minutes for a complete reset, especially on older models.
Step 4: Reconnect the Battery
After waiting:
- Reattach the negative cable to the terminal and tighten the nut securely.
- Turn the ignition to “ON” and check if the check engine light is off.
If the light is off, start the engine and let it idle for a few minutes. The vehicle may run roughly at first as it relearns settings.
Drawbacks of Battery Disconnection
While this method works in some cases, it has limitations:
- It doesn’t fix the problem: If the issue persists, the light will return after the computer rechecks the system.
- It resets other systems: Disconnecting the battery can erase radio presets, clock settings, and adaptive transmission learning.
- It may not work on newer models: Some Infiniti FX35s (especially 2009 and later) have more complex systems that require a scanner to fully reset.
Use this method only as a temporary solution or when a scanner isn’t available.
Method 3: Drive Cycle Reset
After fixing the issue and clearing codes (either with a scanner or battery disconnect), your Infiniti FX35 may need to complete a drive cycle. This is a series of driving conditions that allow the onboard computer to test emissions systems and confirm repairs.
If the check engine light turns off after a successful drive cycle, the reset is complete. If it returns, the problem may still exist.
Recommended Drive Cycle for Infiniti FX35
Follow these steps to complete a standard drive cycle:
- Start with a cold engine: Let the vehicle sit overnight or at least 4–6 hours.
- Drive at varying speeds: Accelerate to 55–60 mph, then decelerate without braking. Repeat 3–5 times.
- Include highway driving: Maintain 55–65 mph for 10–15 minutes.
- Stop and idle: Turn off the engine and let it sit for 30 seconds, then restart and idle for 2–3 minutes.
- Drive in city conditions: Stop-and-go driving for 10–15 minutes.
Complete this cycle over 1–2 days. The check engine light should turn off if all systems pass inspection.
What If the Light Comes Back?
If the light returns after a drive cycle, the issue wasn’t fully resolved. Recheck the trouble codes and inspect the repair. Common mistakes include:
- Using a non-OEM gas cap.
- Not tightening the cap properly (turn until it clicks 3 times).
- Ignoring related components (e.g., replacing an O2 sensor but not cleaning the MAF).
Troubleshooting Tips
Resetting the check engine light isn’t always straightforward. Here are some common issues and solutions:
Light Won’t Turn Off After Reset
- Cause: The problem wasn’t fixed.
- Solution: Re-scan for codes and address the root cause.
Light Returns After a Few Days
- Cause: Intermittent issue or incomplete repair.
- Solution: Monitor driving conditions and recheck components.
Battery Disconnection Didn’t Work
- Cause: The computer retained adaptive memory or the issue persists.
- Solution: Use an OBD2 scanner for a proper reset.
Scanner Won’t Connect
- Cause: Faulty scanner, loose connection, or blown fuse.
- Solution: Check the OBD2 fuse (usually in the fuse box under the dash) and try a different scanner.
When to See a Mechanic
While many check engine light issues can be resolved at home, some require professional help. Consult a certified Infiniti technician if:
- The light flashes (indicating a severe misfire that can damage the catalytic converter).
- You’re unsure how to interpret or fix the trouble code.
- The vehicle runs poorly, stalls, or has reduced power.
- You’ve tried multiple fixes and the light keeps returning.
A mechanic has advanced tools and expertise to diagnose complex issues like internal engine problems or transmission faults.
Conclusion
Resetting the check engine light on your Infiniti FX35 is a manageable task when you follow the right steps. Start by diagnosing the issue with an OBD2 scanner—this is the most reliable method and helps ensure the problem is truly fixed. Whether you use a scanner, disconnect the battery, or complete a drive cycle, always confirm that the underlying cause has been addressed.
Remember, the check engine light is your vehicle’s way of saying, “Hey, something’s not right.” Ignoring it can lead to bigger, costlier problems down the road. By staying proactive and using the methods outlined in this guide, you’ll keep your FX35 running smoothly and your dashboard free of warning lights.
Now that you’re equipped with the knowledge and tools to reset the check engine light, you can tackle this common issue with confidence. Safe driving!