How to Start Infiniti G37 with Dead Key Fob

Having trouble starting your Infiniti G37 because the key fob battery is dead? Don’t panic—there are reliable ways to start your car even without a working remote. This guide walks you through practical, easy-to-follow solutions so you can get back on the road in minutes.

Key Takeaways

• Use the physical key blade: The Infiniti G37 key fob has a hidden metal key that can unlock the driver’s door manually.
• Access the key fob slot: Insert the fob into the emergency start slot near the steering column to start the engine.
• Replace the key fob battery: A dead battery is the most common cause—swap it out with a new CR2032 coin cell.
• Keep a spare fob handy: Having a backup key fob prevents future lockouts and starting issues.
• Check for low battery warnings: Modern G37 models may display dashboard alerts when the fob battery is low.
• Avoid forcing the fob: Never pry or damage the fob casing—use proper tools to avoid breaking internal components.
• Contact Infiniti service if needed: If all else fails, a certified technician can reprogram or replace your key fob.

Introduction: Why Your Infiniti G37 Won’t Start with a Dead Key Fob

You’re running late for work, you hop into your Infiniti G37, press the start button… and nothing happens. The dashboard lights up, but the engine won’t turn over. You try again. Still nothing. Then it hits you—your key fob battery might be dead. It’s a frustrating situation, especially when you’re in a hurry. But don’t worry. This is a common issue with keyless entry systems, and the good news is that your Infiniti G37 is designed with backup solutions to help you out.

Modern vehicles like the Infiniti G37 rely heavily on electronic key fobs for both locking/unlocking and starting the engine. These fobs communicate with the car’s immobilizer system using radio frequency signals. When the battery inside the fob dies, that communication breaks down. The car doesn’t recognize the fob, so it won’t allow the engine to start—even if you’re sitting right inside. This security feature prevents theft, but it can be a real headache when you’re the rightful owner.

The good news? Infiniti engineers anticipated this problem. Your G37 comes equipped with several fail-safes to help you start the car even when the fob isn’t working. From hidden physical keys to emergency start slots, there are multiple ways to get your car running again. In this guide, we’ll walk you through each method step by step, so you’re never stranded again.

Understanding How the Infiniti G37 Key Fob Works

Before diving into solutions, it helps to understand how your key fob actually works. The Infiniti G37 uses a smart key system, also known as a keyless ignition or push-button start. Instead of inserting a traditional key into the ignition, you simply carry the fob with you. As long as the fob is inside the vehicle, you can press the start button to fire up the engine.

The fob contains a small battery—typically a CR2032 coin cell—that powers its internal electronics. This battery sends a unique encrypted signal to the car’s computer every time you press a button or approach the vehicle. The car’s immobilizer system reads this signal and verifies that it matches the one programmed for your vehicle. If it does, the car allows the engine to start. If not—like when the battery is dead—the system blocks ignition.

One key feature of the G37’s smart key is proximity detection. When you walk up to the car with the fob in your pocket or bag, the doors automatically unlock. When you sit in the driver’s seat and press the brake while hitting the start button, the engine starts—no physical key needed. This convenience is great, but it also means that a dead fob can leave you stuck.

Common Signs of a Dead Key Fob Battery

How do you know if the fob battery is the culprit? Here are a few telltale signs:

• Doors won’t unlock automatically: The keyless entry feature stops working. You may need to use the key fob buttons manually, and even then, they might not respond.
• Start button doesn’t work: Pressing the start button results in no response—no cranking, no engine turnover.
• Dashboard warning lights: Some G37 models display a “Key Fob Battery Low” message on the instrument cluster.
• Intermittent fob performance: The fob works sometimes but not others, especially in cold weather or after long periods of disuse.

If you notice any of these symptoms, it’s likely time to replace the battery or use one of the backup starting methods.

Why the Car Won’t Start Even with the Fob Inside

You might wonder: “If the fob is right here in the car, why won’t it start?” The answer lies in the strength of the signal. A dead battery can’t transmit the necessary signal to the car’s receiver, even if the fob is physically present. The immobilizer system is designed to be secure—it won’t take chances. Without a valid signal, it assumes the fob is missing or compromised, so it blocks the engine from starting.

This is why simply holding the fob near the start button or placing it on the dashboard often doesn’t work. The car needs a strong, clear signal to authenticate the key. That’s where the emergency start slot comes in—a clever design that lets you manually trigger the system.

Method 1: Using the Hidden Physical Key Blade

The first and simplest solution is to use the physical key hidden inside your key fob. Every Infiniti G37 key fob has a small metal key blade that can be manually extended to unlock the driver’s door. This is your first line of defense against a dead fob.

Step-by-Step: Accessing the Physical Key

1. Locate the release button: On the side of the key fob, you’ll find a small button or switch. Press and hold it.
2. Pull out the key blade: While holding the button, gently pull the metal key out from the fob. It should slide out smoothly.
3. Unlock the driver’s door: Insert the key into the keyhole on the driver’s door handle (usually hidden under a small cap). Turn it clockwise to unlock.

Once inside, you can proceed to start the car using one of the other methods. But remember—this only gets you into the car. You’ll still need a way to start the engine.

Where to Find the Keyhole on the G37

The keyhole is discreetly located on the driver’s door handle. Look for a small, rectangular cover on the underside or side of the handle. Use the tip of the key blade or a flathead screwdriver to gently pry it open. Once removed, you’ll see the keyhole. Insert the key and turn it to unlock.

This method works even if the fob is completely dead. It’s a mechanical backup that doesn’t rely on batteries or electronics. However, it’s only the first step—you still need to start the engine.

Method 2: Using the Emergency Start Slot

The most effective way to start your Infiniti G37 with a dead key fob is by using the emergency start slot. This is a special port located near the steering column that allows the car to recognize the fob even when its battery is dead.

Locating the Emergency Start Slot

In the Infiniti G37, the emergency start slot is typically found on the lower left side of the steering column, just below the dashboard. It’s a small, rectangular slot labeled “KEY” or marked with a key symbol. You may need to crouch down or use a flashlight to see it clearly.

Some models have the slot integrated into the center console near the cup holders, but the steering column location is most common. Refer to your owner’s manual if you’re unsure.

How to Use the Slot to Start the Car

Follow these steps:

1. Unlock the car: Use the physical key blade to open the driver’s door.
2. Insert the fob: Take the key fob (even with a dead battery) and insert it into the emergency start slot. Push it in firmly until it clicks or stops.
3. Press the brake and start button: With the fob in the slot, press the brake pedal and then press the start button. The engine should turn over and start.

The car’s system uses inductive coupling to read the fob’s internal chip, even without battery power. This allows it to authenticate the key and enable ignition.

Tips for Success

• Make sure the fob is fully inserted: If it’s not seated properly, the car may not detect it.
• Try different orientations: Some fobs work better when inserted a certain way. If it doesn’t work the first time, try flipping it.
• Keep the fob clean: Dirt or moisture on the fob can interfere with the connection. Wipe it with a dry cloth if needed.

This method works in over 95% of cases. If it doesn’t, move on to the next solution.

Method 3: Replacing the Key Fob Battery

The root cause of most dead fob issues is a depleted battery. Replacing it is quick, easy, and costs less than $5. Doing so restores full functionality to your key fob, including remote locking, unlocking, and keyless start.

What You’ll Need

• A new CR2032 3-volt coin cell battery (available at most drugstores, electronics stores, or online)
• A small flathead screwdriver or a plastic prying tool
• A clean, flat workspace

Step-by-Step Battery Replacement

1. Open the key fob: Locate the seam on the side of the fob. Insert the screwdriver into the seam and gently twist to pop the two halves apart. Be careful not to force it—plastic clips can break.
2. Remove the old battery: Once open, you’ll see the battery seated in a small compartment. Use the screwdriver to gently lift it out.
3. Insert the new battery: Place the new CR2032 battery into the compartment, ensuring the positive (+) side is facing up.
4. Reassemble the fob: Snap the two halves back together. Make sure all clips are secure.
5. Test the fob: Stand near your car and press the lock or unlock button. The doors should respond immediately.

Pro Tips for Battery Replacement

• Use a plastic tool: Metal screwdrivers can scratch or damage the fob. A plastic spudger or guitar pick works best.
• Handle the battery carefully: Avoid touching the battery terminals with your fingers—oils can reduce lifespan.
• Dispose of the old battery safely: CR2032 batteries contain lithium and should be recycled at a designated facility.

After replacing the battery, your fob should work like new. You can now start the car normally by pressing the start button with the fob in your pocket or on the seat.

Method 4: Using a Spare Key Fob

If you have a spare key fob, this is the easiest solution. Simply use the backup fob to start the car as you normally would. Most Infiniti owners keep a spare fob in a drawer at home or with a trusted family member.

Why You Should Always Have a Spare

A spare fob acts as a safety net. If your primary fob dies, gets lost, or is damaged, the spare ensures you’re never locked out. It’s especially useful during travel or in emergencies.

How to Get a Spare Fob

If you don’t have a spare, you can obtain one from:

• An Infiniti dealership: They can program a new fob to your vehicle. This is the most reliable method but can cost $200–$400.
• A certified locksmith: Some locksmiths specialize in automotive keys and can program fobs at a lower cost.
• Online retailers: You can buy aftermarket fobs online, but they must be professionally programmed to work with your G37.

Always ensure the fob is properly programmed. An unprogrammed fob won’t start the car, even with a fresh battery.

Method 5: Jump-Starting the Key Fob (Advanced)

In rare cases, you may be able to temporarily revive a dead fob by providing a small external power source. This is not recommended for beginners, but it can work in a pinch.

How It Works

The idea is to use a 3-volt power source (like another CR2032 battery or a coin cell holder with wires) to briefly power the fob’s circuit. This can generate enough signal strength for the car to detect it.

Step-by-Step (Use with Caution)

1. Open the fob: Carefully pry it open as described earlier.
2. Connect a power source: Use alligator clips or tape to connect the positive and negative terminals of a fresh CR2032 to the corresponding contacts in the fob.
3. Insert into emergency slot: While the fob is powered, insert it into the emergency start slot and try to start the car.

Warning: This method can damage the fob if done incorrectly. Only attempt it if you’re comfortable with electronics and have no other options.

Preventing Future Key Fob Issues

Now that you’ve solved the immediate problem, it’s time to prevent it from happening again. A little maintenance goes a long way.

Regular Battery Checks

Check your key fob battery every 6–12 months. Many people only notice it’s dead when they’re stranded. Instead, make it a habit—like checking your smoke detector batteries.

Keep the Fob Clean and Dry

Moisture, dirt, and extreme temperatures can shorten battery life. Store your fob in a dry place, and avoid leaving it in hot cars or near water.

Use a Key Fob Cover

A protective silicone cover can prevent physical damage and reduce wear on the buttons. It also helps keep moisture out.

Monitor Dashboard Warnings

If your G37 displays a “Key Fob Battery Low” message, replace the battery immediately. Don’t wait until it dies completely.

When to Call a Professional

If none of the above methods work, there may be a deeper issue. Possible causes include:

• A damaged key fob (e.g., water damage, cracked circuit board)
• A faulty immobilizer system
• A problem with the car’s antenna or receiver

In these cases, contact an Infiniti dealership or a certified automotive locksmith. They have the tools and expertise to diagnose and fix the problem.

Conclusion: Stay Prepared, Stay Mobile

A dead key fob doesn’t have to leave you stranded. With the right knowledge, you can start your Infiniti G37 quickly and safely—even when the battery is completely drained. Whether you use the hidden key blade, the emergency start slot, or a fresh battery, these solutions are designed to keep you moving.

Remember: prevention is key. Keep a spare fob, replace batteries regularly, and stay aware of warning signs. Your G37 is a reliable machine, and with a little care, it will continue to serve you well for years to come.

Don’t let a dead fob ruin your day. Be prepared, stay calm, and use the methods in this guide to get back on the road in no time.

Frequently Asked Questions

Can I start my Infiniti G37 without a key fob?

Yes, you can start your G37 without a working key fob by using the hidden physical key to unlock the door and inserting the fob into the emergency start slot near the steering column. This allows the car to recognize the key even with a dead battery.

Where is the emergency start slot on an Infiniti G37?

The emergency start slot is usually located on the lower left side of the steering column, just below the dashboard. It’s a small rectangular slot labeled “KEY” or marked with a key symbol.

What type of battery does the Infiniti G37 key fob use?

The Infiniti G37 key fob uses a CR2032 3-volt coin cell battery. It’s widely available at pharmacies, electronics stores, and online retailers.

How long does a key fob battery last?

A typical CR2032 battery in a key fob lasts 3–5 years, depending on usage. Cold weather and frequent use can shorten its lifespan.

Can I drive my G37 with a dead key fob?

Yes, once you start the car using the emergency slot, you can drive normally. However, you won’t be able to lock or unlock the doors remotely until the battery is replaced.

Will a dead key fob drain my car battery?

No, a dead key fob does not drain your car’s battery. The fob only draws power from its own internal battery and does not connect to the vehicle’s electrical system.