Resetting the check engine light on a 1996 Infiniti G20 can be done manually or with an OBD-I scanner. This guide walks you through both methods, ensuring you address the root cause first to avoid recurring issues.
Key Takeaways
- Diagnose the issue first: Never reset the light without fixing the underlying problem—otherwise, it will return.
- Use an OBD-I scanner: The 1996 Infiniti G20 uses OBD-I, so ensure your scanner is compatible.
- Manual reset method works: Disconnecting the battery for 10–15 minutes can clear codes, but may reset radio and clock settings.
- Check the ECM fuse: Removing the ECM fuse for a few minutes is another safe reset option that preserves some vehicle settings.
- Verify repair success: After resetting, drive the car for a few days to confirm the light stays off.
- Avoid cheap code readers: Many modern OBD-II scanners won’t work—invest in an OBD-I compatible tool or visit a mechanic.
- Document error codes: Write down any trouble codes before clearing them for future reference.
How to Reset Check Engine Light on 1996 Infiniti G20
If you’ve been driving a 1996 Infiniti G20 and that pesky check engine light suddenly popped up, you’re not alone. This classic sedan is reliable, but like any older vehicle, it can develop issues that trigger the onboard diagnostics system. The good news? Resetting the check engine light on your 1996 Infiniti G20 is totally doable—whether you’re a DIY enthusiast or just want to save a trip to the mechanic.
But before you rush to turn off that warning light, it’s important to understand what it’s trying to tell you. The check engine light isn’t just a random annoyance—it’s your car’s way of saying, “Hey, something’s not right under the hood.” Ignoring it could lead to bigger, costlier problems down the road. So, the first step isn’t to reset the light—it’s to figure out why it came on in the first place.
In this comprehensive guide, you’ll learn everything you need to know about resetting the check engine light on your 1996 Infiniti G20. We’ll cover how to diagnose the issue, use an OBD-I scanner, perform a manual reset, and verify that the problem is truly fixed. Whether you’re dealing with a loose gas cap or a more serious engine misfire, this guide will walk you through the process step by step—no mechanic required.
By the end, you’ll not only know how to reset the light, but also how to prevent it from coming back. Let’s get started!
Understanding the 1996 Infiniti G20’s Check Engine Light
Before jumping into the reset process, it’s essential to understand how the check engine light works on your 1996 Infiniti G20. This model uses an On-Board Diagnostics I (OBD-I) system, which is different from the more modern OBD-II systems found in cars made after 1996. OBD-I is simpler, less standardized, and requires specific tools or methods to read and clear trouble codes.
When the check engine light illuminates, it means the vehicle’s Engine Control Module (ECM) has detected a problem with the engine, emissions system, or related components. Common triggers include:
– A faulty oxygen (O2) sensor
– Loose or damaged gas cap
– Misfiring spark plugs or ignition coils
– Dirty mass airflow (MAF) sensor
– Exhaust gas recirculation (EGR) valve issues
– Catalytic converter problems
The ECM stores a diagnostic trouble code (DTC) corresponding to the issue. These codes help pinpoint the exact problem, so clearing the light without addressing the root cause is like putting a bandage on a broken bone—it might look fixed, but the issue remains.
That’s why the first step in resetting the check engine light should always be diagnosis. You need to know what’s causing the light to come on before you can safely reset it. Otherwise, you risk damaging your engine or failing an emissions test.
Step 1: Diagnose the Problem Before Resetting
You wouldn’t treat a fever without checking for infection, right? The same logic applies to your car. Resetting the check engine light without diagnosing the issue is risky and often ineffective. The light will likely return within a few miles of driving if the underlying problem isn’t fixed.
So, how do you diagnose the issue on a 1996 Infiniti G20?
Use an OBD-I Scanner
The most accurate way to read trouble codes is with an OBD-I compatible scanner. Unlike OBD-II scanners (which work on most cars from 1996 onward), OBD-I systems like the one in your G20 require specialized tools. Many modern code readers won’t work, so make sure you’re using a scanner designed for pre-1996 vehicles or Japanese imports.
Popular OBD-I scanners for the 1996 Infiniti G20 include:
– Actron CP9575 (with OBD-I adapter)
– Innova 3120 (supports OBD-I)
– Snap-on MODIS or Verus (professional-grade)
Once you have the right scanner, follow these steps:
1. Turn off the engine and locate the diagnostic connector. On the 1996 G20, it’s usually under the dashboard on the driver’s side, near the fuse box. It’s a 14-pin connector, often labeled “CONSULT” or “DIAG.”
2. Plug in your OBD-I scanner.
3. Turn the ignition to the “ON” position (but don’t start the engine).
4. Follow the scanner’s instructions to retrieve trouble codes.
5. Write down the codes—these will help you identify the problem.
For example, code “P0302” indicates a misfire in cylinder 2, while “P0440” points to an evaporative emissions system leak (often a loose gas cap).
Manual Code Reading (Without a Scanner)
Don’t have a scanner? You can still read codes manually using the car’s built-in diagnostic system. Here’s how:
1. Turn the ignition to “ON” (engine off).
2. Locate the diagnostic connector under the dashboard.
3. Use a paperclip or jumper wire to bridge terminals “TE1” and “E1” (refer to your owner’s manual or a repair guide for exact pin locations).
4. Watch the check engine light—it will flash in a pattern that corresponds to the trouble code.
5. Count the flashes: long flashes = tens digit, short flashes = ones digit. For example, two long flashes and three short flashes = code 23.
6. Refer to a 1996 Infiniti G20 trouble code chart to interpret the number.
This method takes a bit of patience, but it’s free and doesn’t require special tools.
Common Issues and Fixes
Once you have the code, research the likely cause. Here are a few common problems and quick fixes:
– **Loose gas cap:** Tighten it or replace it if cracked. This is the #1 cause of false check engine lights.
– **Faulty O2 sensor:** Usually requires replacement. Costs $50–$150 for the part.
– **Dirty MAF sensor:** Clean with MAF cleaner spray (don’t touch the wires).
– **Worn spark plugs:** Replace every 30,000–50,000 miles.
– **Clogged EGR valve:** Clean with carburetor cleaner or replace if stuck.
Fix the issue, then move on to resetting the light.
Step 2: Choose Your Reset Method
Now that the problem is fixed, it’s time to reset the check engine light. You have three main options:
1. Use an OBD-I scanner to clear codes
2. Disconnect the battery
3. Remove the ECM fuse
Each method has pros and cons, so choose the one that best fits your situation.
Method 1: Clear Codes with an OBD-I Scanner
If you used a scanner to read the codes, you can usually clear them with the same device. This is the cleanest and most reliable method.
Steps:
1. With the scanner still connected and the ignition on, navigate to the “Clear Codes” or “Erase DTCs” option.
2. Confirm the action.
3. The scanner will send a command to the ECM to delete the stored trouble codes.
4. Turn off the ignition and disconnect the scanner.
5. Start the engine—the check engine light should be off.
Tip: Some scanners require you to drive the car for a short distance (called a “drive cycle”) before the light fully resets. Check your scanner’s manual for details.
Method 2: Disconnect the Battery
This is the most common DIY method. By cutting power to the ECM, you force it to reset and clear stored codes.
Steps:
1. Turn off the engine and remove the key.
2. Open the hood and locate the battery.
3. Use a wrench to loosen the negative (-) terminal clamp.
4. Disconnect the negative cable and tuck it away from the battery terminal.
5. Wait 10–15 minutes. This gives the ECM enough time to fully discharge and reset.
6. Reconnect the negative cable and tighten it securely.
7. Close the hood and start the car.
The check engine light should be off. However, be aware that disconnecting the battery may also reset:
– Radio presets
– Clock time
– Power window settings
– Transmission adaptive learning (may cause rough shifting for a few drives)
To avoid this, you can use a memory saver device (plugs into the cigarette lighter) to maintain power to the electronics while the battery is disconnected.
Method 3: Remove the ECM Fuse
This method is gentler than disconnecting the battery because it only resets the ECM, not the entire electrical system.
Steps:
1. Turn off the engine and open the hood.
2. Locate the fuse box—usually on the driver’s side near the firewall.
3. Find the ECM fuse (often labeled “ECM,” “ECU,” or “ENGINE”). It’s typically a 10A or 15A fuse.
4. Use a fuse puller or needle-nose pliers to carefully remove the fuse.
5. Wait 5–10 minutes.
6. Reinsert the fuse.
7. Start the car.
This method preserves radio and clock settings but may not work on all G20 models. If the light remains on, try the battery method.
Step 3: Verify the Reset Worked
After resetting the light, don’t assume the job is done. You need to confirm that:
1. The light stays off
2. The original problem is truly fixed
Here’s how to verify success:
Drive the Car
Take your G20 for a 10–15 minute drive, including highway speeds if possible. This allows the ECM to complete a drive cycle and recheck all systems. If the light stays off, you’re in the clear.
Monitor for Symptoms
Watch for signs that the problem persists:
– Rough idling
– Poor fuel economy
– Hesitation or stalling
– Reduced power
If any of these occur, the issue may not be fully resolved.
Recheck for Codes
After a few days of driving, use your OBD-I scanner or manual method to check for new trouble codes. If none appear, the reset was successful.
Troubleshooting Common Reset Issues
Sometimes, the check engine light comes back—or won’t turn off at all. Here’s how to troubleshoot:
Light Returns Immediately
If the light comes back within a few minutes of driving, the problem wasn’t fixed. Recheck your diagnosis and repairs. Common oversights include:
– Forgetting to tighten the gas cap
– Installing the wrong spark plug type
– Not clearing codes after repair
Light Won’t Turn Off
If the light stays on after resetting, possible causes include:
– A persistent fault (e.g., failing catalytic converter)
– ECM needs more time to complete self-tests
– Scanner didn’t fully clear codes
Try driving for 3–5 days. If the light remains, consult a mechanic.
Battery Disconnect Didn’t Work
If disconnecting the battery failed, try:
– Leaving it disconnected longer (30 minutes)
– Using the ECM fuse method
– Ensuring all accessories are off during disconnect
Tips for Preventing Future Check Engine Lights
Now that your light is off, keep it that way with these maintenance tips:
– **Check the gas cap monthly:** Make sure it’s tight and the seal isn’t cracked.
– **Use quality fuel:** Avoid cheap gas with high ethanol content.
– **Replace spark plugs on schedule:** Every 30,000–50,000 miles.
– **Clean the MAF sensor annually:** Use MAF-specific cleaner.
– **Inspect vacuum hoses:** Look for cracks or leaks.
– **Get regular tune-ups:** Especially if you drive in stop-and-go traffic.
Conclusion
Resetting the check engine light on your 1996 Infiniti G20 doesn’t have to be intimidating. With the right tools and a bit of patience, you can diagnose the issue, fix it properly, and clear the light—all without visiting a mechanic.
Remember: the key to success is addressing the root cause first. Whether you use an OBD-I scanner, disconnect the battery, or remove the ECM fuse, always verify that the problem is truly resolved. And don’t forget to maintain your G20 regularly to keep that light off for good.
Your 1996 Infiniti G20 has decades of life left in it—treat it well, and it’ll keep running smoothly for years to come.