Resetting the check engine light on your Infiniti EX35 doesn’t have to be complicated. This guide walks you through safe, effective methods—from using an OBD2 scanner to driving cycles—so you can clear the light and confirm repairs.
Key Takeaways
- Understand why the light came on: The check engine light signals a problem detected by your vehicle’s onboard diagnostics system—don’t ignore it.
- Use an OBD2 scanner for accuracy: A diagnostic tool reads trouble codes and safely resets the light after repairs.
- Never disconnect the battery as a first step: This can cause electrical issues and won’t fix the root problem.
- Complete a drive cycle after resetting: Your EX35 needs to run through specific conditions to verify the issue is resolved.
- Clear codes only after fixing the problem: Resetting without repair may cause the light to return or hide serious issues.
- Keep records of repairs and codes: This helps with future diagnostics and resale value.
- Seek professional help if unsure: Complex issues like catalytic converter or sensor failures require expert diagnosis.
How to Reset Check Engine Light on Infiniti EX35
If you’re driving a Infiniti EX35 and the dreaded check engine light pops up on your dashboard, don’t panic—but don’t ignore it either. This amber warning light is your car’s way of saying, “Hey, something’s not right under the hood.” Whether it’s a loose gas cap or a more serious engine issue, understanding how to properly diagnose and reset the check engine light is essential for maintaining your vehicle’s performance, fuel efficiency, and emissions compliance.
In this comprehensive guide, you’ll learn exactly how to reset the check engine light on your Infiniti EX35—safely and effectively. We’ll walk you through the most reliable methods, including using an OBD2 scanner, performing a drive cycle, and even temporary fixes (with caution). You’ll also discover why simply disconnecting the battery isn’t the best solution and what steps to take before and after resetting the light. By the end, you’ll feel confident handling this common automotive issue like a pro.
Why the Check Engine Light Comes On
Visual guide about How to Reset Check Engine Light on Infiniti Ex35
Image source: pasadenacertified.com
Before you reset the 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 Infiniti EX35’s onboard diagnostics system (OBD2). This system constantly monitors engine performance, emissions, fuel system efficiency, and various sensors.
When a problem is detected, the system stores a diagnostic trouble code (DTC) and illuminates the check engine light. Common triggers include:
- A loose or faulty gas cap
- Oxygen (O2) sensor failure
- Mass airflow (MAF) sensor issues
- Catalytic converter problems
- Spark plug or ignition coil malfunctions
- Evaporative emissions system leaks
Ignoring the light can lead to reduced fuel economy, increased emissions, and even engine damage over time. That’s why diagnosing the root cause is the first—and most important—step.
Method 1: Using an OBD2 Scanner (Recommended)
The most accurate and safest way to reset the check engine light on your Infiniti EX35 is by using an OBD2 scanner. This handheld device plugs into your car’s diagnostic port and communicates directly with the engine control unit (ECU).
Step 1: Locate the OBD2 Port
In the Infiniti EX35 (2008–2013 models), the OBD2 port is typically located under the dashboard on the driver’s side. You’ll find it near the steering column, often behind a small plastic panel. It’s a 16-pin connector that looks like a trapezoid.
To access it:
- Sit in the driver’s seat and look down near your knees.
- Gently pull off the plastic cover if present.
- The port should be clearly visible and easy to reach.
Step 2: Plug in the OBD2 Scanner
Turn off the ignition before connecting the scanner. Then:
- Insert the scanner’s plug firmly into the OBD2 port.
- Turn the ignition to the “ON” position (but don’t start the engine).
- Wait for the scanner to power up and establish a connection.
Most modern scanners will display “Connected” or “Ready” once linked to the vehicle.
Step 3: Read the Trouble Codes
Once connected, use the scanner to read the stored trouble codes. These codes (like P0420 or P0171) tell you exactly what system or component is malfunctioning.
For example:
- P0420: Catalyst system efficiency below threshold
- P0171: System too lean (Bank 1)
- P0455: Large evaporative emission leak
Write down the codes or take a photo for reference. This information is vital for diagnosing the issue.
Step 4: Fix the Underlying Problem
Before resetting the light, you must address the root cause. For instance:
- If the code indicates a loose gas cap, tighten it or replace it.
- If it’s an O2 sensor, you may need to replace the faulty unit.
- For a MAF sensor issue, clean it with MAF cleaner or replace it.
Skipping this step means the light will likely come back on after resetting.
Step 5: Clear the Codes and Reset the Light
Once the repair is complete:
- On your scanner, select “Clear Codes” or “Erase DTCs.”
- Confirm the action when prompted.
- The scanner will send a command to the ECU to turn off the check engine light.
The light should go off immediately. If it doesn’t, double-check the connection or try restarting the ignition.
Step 6: Verify the Reset
Turn the ignition off, wait 10 seconds, then turn it back on. The check engine light should remain off. If it reappears, the problem may not be fully resolved, or a new issue has developed.
Method 2: Drive Cycle Reset (No Scanner Needed)
If you don’t have an OBD2 scanner, your Infiniti EX35 may reset the check engine light automatically after completing a “drive cycle.” This is a series of driving conditions that allow the vehicle’s computer to retest systems and confirm repairs.
What Is a Drive Cycle?
A drive cycle is a specific sequence of driving maneuvers designed to trigger all monitored systems. Once completed successfully, the ECU may clear stored trouble codes and turn off the check engine light—if the underlying issue is fixed.
Infiniti EX35 Drive Cycle Steps
Follow this general drive cycle for the EX35:
- Start with a cold engine: Let the car sit overnight so the engine is below 120°F.
- Drive at 50–60 mph for 3–5 minutes: This warms up the engine and oxygen sensors.
- Accelerate to 60 mph, then coast down to 30 mph: Do this 3–5 times to test the catalytic converter.
- Drive in stop-and-go traffic for 10–15 minutes: Include idling, accelerating, and braking.
- End with a steady 55 mph cruise for 5 minutes: This completes the monitoring cycle.
After completing the drive cycle, turn off the car and wait 10 minutes. Then restart it. If the light remains off, the reset was successful.
Note: This method only works if the original problem has been fixed. If the issue persists, the light will return.
Method 3: Disconnecting the Battery (Not Recommended)
Some people try to reset the check engine light by disconnecting the car battery. While this can clear codes temporarily, it’s not the best approach—especially for modern vehicles like the Infiniti EX35.
Why It’s Risky
Disconnecting the battery can:
- Reset the ECU and erase adaptive learning data (fuel trims, idle settings).
- Cause the radio, navigation, or security system to lock.
- Trigger other warning lights or error messages.
- Not fix the underlying issue—leading to the light returning.
If You Must Do It: Step-by-Step
If you choose this method, follow these steps carefully:
Step 1: Turn Off the Ignition
Make sure the car is completely off and the keys are removed.
Step 2: Disconnect the Negative Terminal
Use a wrench to loosen the nut on the negative (black) battery terminal. Remove the cable and tuck it away from the battery.
Step 3: Wait 15–30 Minutes
This allows the ECU to fully discharge and reset. Some recommend pressing the brake pedal a few times to drain residual power.
Step 4: Reconnect the Battery
Reattach the negative cable and tighten the nut securely.
Step 5: Restart the Car
Turn the ignition on and let the car idle for 5–10 minutes. The check engine light may be off—but monitor it closely.
Step 6: Drive and Observe
Take the car for a short drive. If the light returns, the problem wasn’t fixed.
Tip: After reconnecting the battery, you may need to reset the radio presets, clock, and power windows.
What to Do After Resetting the Light
Resetting the check engine light is only half the battle. To ensure long-term reliability, follow these post-reset steps:
Monitor the Light
Keep an eye on the dashboard. If the light comes back on within a few days, the issue likely wasn’t fully resolved.
Complete a Drive Cycle
Even after using a scanner, completing a drive cycle helps the ECU confirm that all systems are functioning properly. This is especially important for emissions testing.
Check for Pending Codes
Some OBD2 scanners can read “pending” codes—issues that haven’t yet triggered the light but are being monitored. Address these early to prevent future problems.
Keep a Repair Log
Record the date, trouble codes, repairs made, and parts replaced. This helps with future diagnostics and increases resale value.
Schedule Regular Maintenance
Prevent future check engine light issues by following your EX35’s maintenance schedule:
- Replace spark plugs every 60,000–100,000 miles
- Inspect and clean the MAF sensor annually
- Check the gas cap for cracks or wear
- Use high-quality fuel and oil
Troubleshooting Common Issues
Even with the right tools, you might run into problems when resetting the check engine light. Here’s how to handle common scenarios:
Light Comes Back On Immediately
If the light returns right after resetting:
- The underlying issue wasn’t fixed.
- A new problem has developed.
- The ECU hasn’t completed its self-tests yet.
Solution: Re-scan for codes and address the root cause.
Scanner Won’t Connect
If your OBD2 scanner won’t link to the car:
- Check that the ignition is on (but engine off).
- Ensure the OBD2 port is clean and undamaged.
- Try a different scanner or update the software.
Radio or Electronics Reset
After disconnecting the battery:
- Enter the radio code (found in the owner’s manual or glove box).
- Reset the clock and power windows.
- Some systems may require a dealership reset.
Check Engine Light Flashes
A flashing light indicates a severe misfire that can damage the catalytic converter. Pull over safely and have the car towed to a repair shop.
When to See a Mechanic
While many check engine light issues can be handled at home, some problems require professional diagnosis and repair. Seek a certified mechanic if:
- The light is flashing (indicating a serious misfire).
- You’re unsure how to interpret trouble codes.
- The repair involves complex components like the catalytic converter or ECU.
- The light keeps returning despite your efforts.
- You notice performance issues like rough idling, stalling, or loss of power.
Infiniti dealerships and specialized import shops have advanced diagnostic tools and experience with EX35-specific issues.
Final Tips for Infiniti EX35 Owners
Owning a Infiniti EX35 is a pleasure, but like any vehicle, it needs attention. Here are a few extra tips to keep your check engine light off for good:
- Use a quality OBD2 scanner: Invest in a reliable scanner like the BlueDriver or Autel MaxiCOM. They offer live data, code definitions, and reset functions.
- Don’t ignore the gas cap: A loose or damaged cap is one of the most common causes of the check engine light. Tighten it or replace it if cracked.
- Use premium fuel occasionally: While the EX35 runs on regular gas, using premium fuel every few tanks can help clean fuel injectors and reduce carbon buildup.
- Check for technical service bulletins (TSBs): Infiniti may have issued updates for common EX35 issues. Search online or ask your dealer.
- Stay proactive: Regular maintenance prevents most check engine light problems before they start.
Conclusion
Resetting the check engine light on your Infiniti EX35 doesn’t have to be intimidating. With the right tools and knowledge, you can diagnose the issue, make the necessary repairs, and clear the light safely. The OBD2 scanner method is the most reliable, while drive cycles offer a no-cost alternative if the problem is fixed. Avoid quick fixes like disconnecting the battery unless absolutely necessary.
Remember: the check engine light is your car’s way of communicating. Listen to it, address the root cause, and keep your EX35 running smoothly for years to come. Whether you’re a DIY enthusiast or prefer professional help, staying informed is the key to confident car ownership.