Reset your 2026 Chrysler 300 check engine light safely and quickly by using an OBD2 scanner—this is the most reliable method recommended by experts. Simply plug the scanner into the port under the dashboard, clear the error codes, and verify the fix by restarting the engine. Avoid quick “off” tricks—they don’t address the root cause and may lead to recurring warnings.

How to Reset Chrysler 300 Check Engine Light in 2026

Key Takeaways

• Diagnose first: Always scan for trouble codes before resetting the light.
• OBD2 scanner: Use a reliable OBD2 tool for accurate resets.
• Battery disconnect: Try disconnecting the battery for 10+ minutes.
• Drive cycle: Complete a drive cycle to verify the issue is fixed.
• Recheck codes: Confirm the light stays off after resetting.
• Address root cause: Never ignore recurring warning lights.

Why This Matters / Understanding the Problem

That little orange engine light on your dashboard isn’t just annoying—it’s a cry for help from your 2026 Chrysler 300. Whether it’s a loose gas cap or something more serious, ignoring the check engine light can lead to poor fuel economy, reduced performance, or even costly repairs down the road.

But here’s the good news: in many cases, the issue is simple, and knowing how to reset the Chrysler 300 check engine light in 2026 can save you a trip to the mechanic. The key is understanding when to reset it and how to do it safely—without masking a real problem.

Modern Chrysler 300 models use an OBD2 (On-Board Diagnostics II) system that stores trouble codes. Resetting the light without fixing the root cause is like putting duct tape over a smoke alarm. That’s why the best approach combines diagnosis and reset—ensuring your car is truly healthy before turning off the warning.

Whether you’re a DIY enthusiast or just want to avoid unnecessary repair bills, learning how to reset the Chrysler 300 check engine light in 2026 gives you more control over your vehicle’s maintenance. This guide walks you through the process step by step, using tools you might already have at home.

What You Need

You don’t need a mechanic’s degree or a full toolbox to reset the check engine light. Here’s a simple list of what you’ll need—most of which you can grab from your garage or local auto parts store.

• OBD2 scanner (also called a code reader) – This is the most reliable tool. Look for one with a “Clear Codes” or “Reset” function. Budget-friendly options start at $20.
• Smartphone (optional) – Some Bluetooth OBD2 scanners connect to free apps like Torque Pro or OBD Fusion, giving you more detailed diagnostics.
• Flashlight – Helps you locate the OBD2 port, especially in low-light conditions.
• Pen and paper (or phone notes app) – Write down any trouble codes before clearing them. This helps you track recurring issues.
• Your Chrysler 300 owner’s manual – Useful for locating the OBD2 port and understanding warning messages.

You don’t need jumper cables, a multimeter, or any mechanical tools—this process is electronic, not mechanical. But having the right OBD2 scanner is non-negotiable. It’s the only way to safely and correctly reset the Chrysler 300 check engine light in 2026 while also checking for real problems.

Pro Tip: If you plan to do your own car maintenance, investing in a quality OBD2 scanner pays for itself in just one use. Look for models with live data streaming and freeze-frame capabilities—they help diagnose intermittent issues.

Step-by-Step Guide to How to Reset Chrysler 300 Check Engine Light in 2026

Now that you’re prepared, let’s get into the nitty-gritty. This method works for all 2026 Chrysler 300 trims, including the base Touring, Limited, and the high-performance 300C. The process takes about 10–15 minutes and requires zero mechanical skills.

Step 1: Park Safely and Turn Off the Engine

Start by pulling over in a safe, flat area—your driveway, garage, or parking lot. Make sure the car is fully stopped, in park, and the engine is off. Engage the parking brake to prevent rolling.

Why? The OBD2 system only reads codes when the ignition is on but the engine is off. Starting this step ensures you won’t accidentally damage any sensors or electronics.

Also, wait a few minutes after driving. The engine and exhaust system need to cool slightly to avoid false readings from thermal expansion.

Step 2: Locate the OBD2 Port

In all 2026 Chrysler 300 models, the OBD2 port is located under the dashboard on the driver’s side. It’s a 16-pin rectangular plug, usually found:

• Just below the steering column
• Behind a small plastic cover (sometimes labeled “OBD”)
• About 6–8 inches from the floor

Use your flashlight if needed. If you can’t find it, check your owner’s manual—page 120 in the 2026 Chrysler 300 manual shows an exact diagram.

Warning: Don’t confuse the OBD2 port with the 12V power outlet or USB ports nearby. The OBD2 has 16 pins arranged in two rows of eight. Plugging in the wrong device could damage the port.

Step 3: Plug in the OBD2 Scanner

Take your OBD2 scanner and gently plug it into the port. Make sure it’s fully seated—there should be no wiggling or loose connection. The scanner will light up or power on once connected.

If you’re using a Bluetooth model, turn on your phone’s Bluetooth and pair it with the scanner. Open your diagnostic app (like Torque Pro) and wait for the connection.

For wired scanners, press the power button if needed. Most will auto-detect the vehicle once plugged in.

This step is critical for how to reset the Chrysler 300 check engine light in 2026—without a solid connection, the scanner can’t communicate with the car’s computer.

Step 4: Turn the Ignition to “On” (But Don’t Start the Engine)

Insert your key or press the start button without pressing the brake pedal. You want the car to be in “Accessory” or “Ignition On” mode. The dashboard lights should turn on, but the engine stays off.

Why not start the engine? The OBD2 system reads stored codes when the engine is off. Starting it could trigger new codes or interfere with the reading.

Wait 10–15 seconds for the scanner to establish communication. You’ll usually see a message like “Connecting…” or “Scanning ECU.”

Step 5: Read the Trouble Codes

Now, select “Read Codes” or “Trouble Codes” on your scanner. The device will retrieve all stored diagnostic trouble codes (DTCs), such as P0457 (evaporative leak) or P0300 (random misfire).

Write down the codes—even if you plan to clear them. This helps you research the issue later or discuss it with a mechanic if needed.

Some scanners show a brief description (e.g., “O2 Sensor Circuit Low”), while others only show the code. Use online resources like OBD-Codes.com or your app’s built-in database to interpret them.

Real-Life Example: A P0457 code often means a loose gas cap. Tighten it, drive for 50 miles, and the light may reset itself. But a P0301 (cylinder 1 misfire) could mean a bad spark plug or coil—needs attention.

Step 6: Diagnose Before You Reset (Critical!)

Never skip this step. Clearing codes without fixing the issue is like silencing a smoke alarm while your kitchen burns.

Ask yourself:

• Did I recently fill up gas? → Check the gas cap.
• Is the light steady or flashing? → Flashing means serious engine misfire. Don’t drive far.
• Are there other symptoms? → Rough idle, loss of power, or strange smells mean don’t reset yet.

If the code is minor (e.g., P0457 from a loose cap), tighten the cap, drive a few days, and see if the light goes off naturally. If it persists, then reset.

For major codes (e.g., P0171 – lean fuel mixture), consult a mechanic or use your scanner to monitor live data before resetting.

This is the most important part of how to reset the Chrysler 300 check engine light in 2026—diagnose first, reset second.

Step 7: Clear the Trouble Codes

Once you’ve addressed the issue (or confirmed it’s minor), go to your scanner’s menu and select “Clear Codes” or “Erase DTCs.”

Confirm the action. The scanner will send a command to the car’s ECU (Engine Control Unit) to delete all stored codes.

You’ll usually see a message like “Codes Cleared” or “Success.” The check engine light may turn off immediately, or it might take a few seconds.

Unplug the scanner. Turn the ignition off, then back on. The light should stay off.

Pro Tip: Some scanners have a “Reset MIL” (Malfunction Indicator Light) option—use that instead of “Clear Codes” if available. It’s the same thing but more precise.

Step 8: Drive and Monitor

Start the engine and drive normally for at least 20–30 minutes. The Chrysler 300’s computer needs a “drive cycle” to run self-checks and confirm everything is working.

During this time, the car will:

• Monitor oxygen sensors
• Test the EVAP system
• Check for misfires

If the issue was truly fixed, the light won’t come back. If it returns within a few days, the problem persists—don’t reset it again. Get it diagnosed properly.

Most emissions-related codes take 3–5 drive cycles to fully clear. So even if the light stays off, keep an eye on it for a week.

Step 9: Verify with the Scanner (Optional but Smart)

After a few days, plug the scanner back in and check for codes again. Even if the light is off, some codes might still be pending.

Look for:

• Stored codes – These are from past issues and can usually be ignored if the light is off.
• Pending codes – These are new problems the car detected but hasn’t confirmed. Monitor them.

This final check ensures the reset was successful and gives you peace of mind.

Pro Tips & Common Mistakes to Avoid

Resetting the check engine light is simple, but small mistakes can lead to big headaches. Here’s what the pros know—and what you should too.

Pro Tip 1: Use the Right Scanner

Not all OBD2 scanners are equal. A $15 basic reader might clear codes, but it won’t show live data or freeze-frame info. For how to reset the Chrysler 300 check engine light in 2026, invest in a mid-range scanner ($40–$80) that offers:

• Live data streaming
• Freeze-frame data (conditions when the code triggered)
• Emissions readiness monitors

Example: The BlueDriver Pro or Autel MaxiCOM MK808 are excellent choices.

Pro Tip 2: Reset After Repairs, Not Before

Many people reset the light before fixing the problem—then wonder why it comes back. Always:

1. Diagnose the issue
2. Fix it (e.g., replace O2 sensor, tighten gas cap)
3. Reset the light

Think of it like treating a fever—resetting the light without treating the cause just hides the symptom.

Common Mistake: Using the “Battery Disconnect” Trick

Some online guides suggest disconnecting the car battery to reset the check engine light. While it can work, it’s outdated and risky.

• Why it’s bad: It erases all ECU memory, including radio presets, seat memory, and learned driving patterns.
• Worse: It can trigger a “check battery” or “check charging system” warning, creating a new problem.

Plus, modern Chrysler 300 models have backup capacitors that prevent a full reset from a battery disconnect. So it often doesn’t work anyway.

Warning: Avoid this method. It’s unreliable, can damage electronics, and doesn’t help diagnose the real issue. Stick with the OBD2 scanner.

Common Mistake: Ignoring a Flashing Light

A steady check engine light means “investigate soon.” A flashing light means “stop driving now.” It indicates a severe misfire that can damage the catalytic converter.

If the light is flashing, don’t reset it. Get the car towed to a mechanic. Resetting it could cost you hundreds in catalytic converter repairs.

Pro Tip 3: Keep a Maintenance Log

Every time you reset the light, record:

• Date
• Code(s) found
• Action taken (e.g., “tightened gas cap”)
• Light status after reset

This log helps spot patterns. For example, if P0457 keeps coming back, your EVAP system might have a small leak—not just a loose cap.

Pro Tip 4: Use Freeze-Frame Data

When you read the code, your scanner can show freeze-frame data: speed, RPM, engine temp, and fuel trim when the code triggered. This helps you reproduce the issue.

Example: A P0171 code (lean condition) that only appears at highway speeds might be a clogged fuel filter. One that appears at idle could be a vacuum leak.

FAQs About How to Reset Chrysler 300 Check Engine Light in 2026

Q1: Can I reset the check engine light without a scanner?

Technically, yes—but it’s not recommended. You can try the “ignition cycle” method: turn the key to “On” for 10 seconds, off for 10 seconds, repeat 3 times. But it rarely works on modern cars like the 2026 Chrysler 300.

For a reliable, safe reset, an OBD2 scanner is the only way. It ensures you don’t mask a real problem. Plus, it costs less than a single mechanic visit.

Q2: Will resetting the light pass emissions testing?

Only if all emissions monitors are “ready.” After resetting, your car needs to complete a full drive cycle (usually 100–200 miles) for the ECU to recheck systems.

If you reset the light the day before an emissions test, the monitors may still show “not ready,” and you’ll fail. Always drive for a week after resetting before testing.

Q3: Why does the light come back after resetting?

Because the root problem wasn’t fixed. For example:

• Loose gas cap → tighten it
• Bad O2 sensor → replace it
• Vacuum leak → find and seal it

Resetting the light doesn’t fix anything—it only clears the code. If the issue persists, the light will return.

Q4: Is it illegal to reset the check engine light?

No. It’s not illegal to reset the light yourself. But if you do it to pass an emissions test without fixing the problem, that could be considered tampering in some states.

Always fix the issue first. Resetting is a tool, not a cover-up.

Q5: Can a bad battery cause the check engine light to come on?

Yes. A weak or failing battery can cause voltage fluctuations, triggering false codes like P0562 (low system voltage) or P0335 (crankshaft sensor).

Before resetting, check your battery voltage with a multimeter. It should read 12.6V when off and 13.8–14.4V when running. If not, charge or replace the battery first.

Q6: How much does it cost to reset the check engine light at a mechanic?

Most shops charge $80–$120 for a diagnostic and reset. But if you do it yourself with a $25 OBD2 scanner, you save money and learn about your car.

Plus, you can reset it anytime—no appointment needed.

Q7: Can I use my phone to reset the light?

Yes—if you have a Bluetooth OBD2 scanner and a compatible app (like Torque Pro, Car Scanner, or OBD Fusion).

Pair the scanner, open the app, read codes, and tap “Clear Codes.” It’s just as effective as a handheld scanner, and many apps show live data in real time.

Final Thoughts

Knowing how to reset the Chrysler 300 check engine light in 2026 isn’t just about silencing a warning—it’s about taking control of your car’s health. With the right tools and a smart approach, you can diagnose minor issues, avoid unnecessary repairs, and keep your 300 running smoothly.

Remember: reset the light only after you’ve addressed the cause. Use an OBD2 scanner, not gimmicks. And keep a log of codes and fixes—it’s your car’s medical history.

Whether it’s a loose gas cap or a faulty sensor, you now have the knowledge to act fast. And if the problem is beyond your skill level? That’s okay. The scanner gives you the info you need to talk confidently with a mechanic.

So next time that engine light pops on, don’t panic. Grab your scanner, follow these steps, and reset the Chrysler 300 check engine light in 2026 with confidence. Your car—and your wallet—will thank you.

Actionable Advice: Buy an OBD2 scanner today. Keep it in your glovebox. Use it every time the light comes on. It’s the smartest $25–$80 you’ll spend on car maintenance.