This guide walks you through how to clear the Service Engine Soon light on a G35 using simple tools and proven methods. You’ll learn when it’s safe to reset the light and when professional help is needed.
Key Takeaways
- Understand the cause first: The Service Engine Soon light can indicate anything from a loose gas cap to a serious engine issue. Diagnosing the problem before clearing the light is essential.
- Use an OBD2 scanner for accuracy: A diagnostic tool reads trouble codes and helps identify the root cause. This is the most reliable way to address the issue.
- Manual reset methods exist but aren’t always effective: Some G35 owners try battery disconnection or button combinations, but these may not work on all models or clear all codes.
- Clear the light only after fixing the problem: Resetting the light without repairing the underlying issue will cause it to return—and could lead to bigger problems.
- Prevent future warnings with regular maintenance: Keeping up with oil changes, air filters, and spark plugs reduces the chances of triggering the light.
- Know when to see a mechanic: If the light flashes or returns quickly, it’s a sign of a serious issue that needs professional attention.
- Keep a repair log: Tracking repairs and resets helps you monitor your G35’s health over time.
How to Clear Service Engine Soon Light G35
If you’re driving an Infiniti G35 and the dreaded “Service Engine Soon” light pops up on your dashboard, don’t panic. While it can be alarming, this warning light is your car’s way of saying something needs attention. The good news? In many cases, you can clear the light yourself—especially if the issue is minor. This guide will walk you through everything you need to know about how to clear the Service Engine Soon light on a G35, from diagnosing the problem to safely resetting the system.
Whether you’re a DIY enthusiast or just trying to save a trip to the mechanic, this step-by-step guide will help you understand what’s going on under the hood and how to fix it. We’ll cover the tools you need, common causes of the light, and the best methods to reset it—without causing further damage.
What Does the Service Engine Soon Light Mean?
Visual guide about How to Clear Service Engine Soon Light G35
Image source: trustmymechanic.com
The “Service Engine Soon” light (also known as the Check Engine Light) is part of your G35’s onboard diagnostic system. When it illuminates, it means the car’s computer has detected a problem with the engine, emissions, or related systems.
It’s important to note that this light isn’t just about maintenance—it can signal anything from a loose gas cap to a failing oxygen sensor or catalytic converter. The severity varies, so you should never ignore it.
Common Causes of the Light
- Loose or damaged gas cap
- Faulty oxygen (O2) sensor
- Misfiring engine (bad spark plugs or coils)
- Mass airflow (MAF) sensor issues
- Catalytic converter problems
- Evaporative emissions system leaks
Understanding the cause is the first step. Clearing the light without fixing the issue is like turning off a smoke alarm while your kitchen is on fire—it doesn’t solve the problem.
Tools You’ll Need
Before you start, gather these tools:
- OBD2 scanner (Bluetooth or wired)
- Basic hand tools (screwdriver, wrench)
- Replacement parts (if needed, like a gas cap or sensor)
- Clean cloth and gloves
An OBD2 scanner is the most important tool. It plugs into your G35’s diagnostic port and reads trouble codes that tell you exactly what’s wrong. You can find affordable scanners online or at auto parts stores.
Step 1: Diagnose the Problem
Never clear the light without knowing why it came on. Here’s how to diagnose the issue:
Locate the OBD2 Port
In the G35, the OBD2 port is usually under the dashboard on the driver’s side, near the steering column. It’s a 16-pin connector that looks like a trapezoid.
Plug in the Scanner
Turn the ignition to the “ON” position (but don’t start the engine). Plug the OBD2 scanner into the port. Follow the scanner’s instructions to read the trouble codes.
Interpret the Codes
The scanner will display a code like P0420 or P0171. Write it down and look it up online or in the scanner’s manual. For example:
- P0420: Catalytic converter efficiency below threshold
- P0171: System too lean (not enough fuel)
- P0455: Large evaporative emissions leak (often a gas cap issue)
This step tells you what needs fixing. If you’re unsure, take the code to an auto parts store—many offer free code reading.
Step 2: Fix the Underlying Issue
Once you know the cause, address it before clearing the light.
Example: Loose Gas Cap
If the code points to an emissions leak (like P0455), check the gas cap. Make sure it’s tight and the seal isn’t cracked. Replace it if necessary—gas caps are cheap and often the culprit.
Example: Faulty O2 Sensor
If the code is P0135 or P0141, you may have a bad oxygen sensor. These sensors monitor exhaust gases and help the engine run efficiently. Replacing one takes about 30 minutes with basic tools.
Example: Misfire (P0300-P0306)
A misfire code means one or more cylinders aren’t firing properly. This is often due to worn spark plugs or ignition coils. Replace the affected parts and clear the code.
Step 3: Clear the Service Engine Soon Light
After fixing the problem, it’s time to reset the light. Here are the most effective methods:
Method 1: Use an OBD2 Scanner (Recommended)
This is the safest and most reliable way to clear the light.
- Plug the scanner into the OBD2 port.
- Turn the ignition to “ON.”
- Navigate to the “Clear Codes” or “Erase DTCs” option on the scanner.
- Confirm the reset.
- Turn off the ignition and unplug the scanner.
The light should go off. Start the engine to confirm it stays off.
Method 2: Disconnect the Battery (Not Always Effective)
Some people try disconnecting the battery to reset the computer. Here’s how:
- Turn off the engine and remove the key.
- Disconnect the negative battery terminal using a wrench.
- Wait 15–30 minutes (this drains residual power from the ECU).
- Reconnect the terminal and tighten it securely.
- Start the engine.
Note: This method doesn’t always work on modern G35 models. It may also reset radio presets, clock, and other settings.
Method 3: Drive Cycle Reset (Natural Clear)
If you’ve fixed the issue, the light may turn off on its own after a few drive cycles. A drive cycle is a series of driving conditions (cold start, highway driving, stops, etc.) that allow the car’s computer to retest systems.
This can take 3–7 days of normal driving. However, if the light stays on, use a scanner to clear it manually.
Troubleshooting Tips
Sometimes, the light won’t clear—or it comes back. Here’s what to do:
Light Won’t Turn Off
- Double-check that the problem is fixed. A loose gas cap or unplugged sensor can prevent the light from clearing.
- Make sure the scanner is compatible with your G35’s year and model.
- Try a different scanner or visit an auto parts store for a free reset.
Light Comes Back On
If the light returns within a few days, the issue wasn’t fully resolved. Re-scan for codes and inspect related components. For example, a P0420 code might return if the catalytic converter is failing, even after cleaning.
Flashing Light
A flashing Service Engine Soon light indicates a severe misfire that can damage the catalytic converter. Pull over safely, turn off the engine, and call a tow truck. Driving with a flashing light can cause expensive damage.
Preventing Future Warnings
The best way to avoid the Service Engine Soon light is through regular maintenance:
- Replace spark plugs every 60,000–100,000 miles.
- Change the air filter every 15,000–30,000 miles.
- Use high-quality fuel and oil.
- Inspect the gas cap during oil changes.
- Keep the engine bay clean to prevent sensor contamination.
A well-maintained G35 is less likely to trigger warning lights.
When to See a Mechanic
While many issues can be fixed at home, some require professional help:
- The light is flashing.
- Multiple codes appear at once.
- The car runs rough, stalls, or loses power.
- You’re unsure how to interpret or fix the code.
A certified mechanic has advanced tools and experience to diagnose complex issues like transmission problems or internal engine faults.
Final Thoughts
Clearing the Service Engine Soon light on your G35 doesn’t have to be stressful. With the right tools and knowledge, you can diagnose the problem, fix it, and reset the light safely. Remember: the light is there to protect your car. Ignoring it can lead to costly repairs down the road.
Always start with a proper diagnosis using an OBD2 scanner. Fix the root cause, then clear the code. And don’t forget routine maintenance—it’s the best way to keep your G35 running smoothly for years to come.
By following this guide, you’ll not only clear the light but also gain confidence in maintaining your vehicle. Stay proactive, stay informed, and enjoy the drive.