# How to Replace Key Fob Battery 2017 Ford Fusion

> ClearTheCode — Restore your 2017 Ford Fusion key fob's full functionality with our easy DIY guide. Learn how to quickly replace the battery (CR2450) and get back seamless remote access. Save time and money!

Source: https://clearthecode.com/articles/key-fob-battery-replacement-diy-ford-fusion-2017
Author: ClearTheCode

# How to Replace Key Fob Battery 2017 Ford Fusion

Is your 2017 Ford Fusion key fob acting up? Perhaps it's not locking or unlocking the doors reliably, or maybe the remote start isn't working as it should. Often, the simplest explanation is a dead or dying battery inside the key fob itself. This guide will walk you through the straightforward process of replacing the key fob battery in your 2017 Ford Fusion, getting you back to seamless remote access. This common DIY task can save you a trip to the dealership and restore your convenience in minutes.

## At a glance: difficulty, repair cost, and diagnostic workflow

- **Difficulty Rating:** 6/10 — Easy to moderate
- **Common Symptoms:** Intermittent functionality: The key fob works sometimes, but not always, requiring multiple button presses to lock, unlo; Reduced range: You have to be much closer to the vehicle for the key fob to respond, sometimes even standing right next ; No response at all: The key fob stops working entirely, leaving you to use the physical key hidden inside the fob to unl; Delayed response: There's a noticeable lag between pressing a button and the vehicle responding.
- **Estimated Repair Cost:** $80–$900 (parts + typical shop labor)
- **OEM Tooling Required:** Standard OBD-II scanner and hand tools

**Diagnostic workflow:**
1. Confirm the symptom on your 2017 Ford FUSION.
2. Scan for stored or pending codes with an OBD-II tool.
3. Inspect the most common causes in this guide (visual checks first).
4. Run verification tests before replacing parts.
5. Repair, clear codes, and verify on a test drive.

Browse the [model repair hub](/vehicles/ford/fusion) and [make hub](/vehicles/ford) for related guides.

## Symptoms of a Dying Key Fob Battery

Drivers of the 2017 Ford Fusion typically notice a range of symptoms when their key fob battery starts to fail. These issues often begin subtly and worsen over time:

*   **Intermittent functionality:** The key fob works sometimes, but not always, requiring multiple button presses to lock, unlock, or activate the remote start.
*   **Reduced range:** You have to be much closer to the vehicle for the key fob to respond, sometimes even standing right next to the driver's door.
*   **No response at all:** The key fob stops working entirely, leaving you to use the physical key hidden inside the fob to unlock the doors manually.
*   **Delayed response:** There's a noticeable lag between pressing a button and the vehicle responding.
*   **"Key Fob Battery Low" message:** Your vehicle's instrument cluster may display a warning message indicating that the key fob battery is weak. This is a clear indicator that a replacement is due.
*   **Remote start failure:** The remote start feature, a popular convenience for Fusion owners, may stop working or become unreliable.

If you're experiencing any of these issues, a dead or dying key fob battery is the most probable cause.

## Verifying the Issue

Before you proceed with replacing the battery, it's good practice to verify that the key fob battery is indeed the problem.

1.  **Check for dashboard warnings:** As mentioned, your 2017 Ford Fusion might display a "Key Fob Battery Low" message. This is the most direct confirmation.
2.  **Try a second key fob:** If you have another key fob for your Fusion, try using it. If the second fob works perfectly, it strongly suggests the issue is with the first fob's battery. If both fobs are malfunctioning, it could point to a different issue, though it's still possible both batteries are weak, especially if they were purchased or used around the same time.
3.  **Proximity test:** Stand very close to the driver's door and try the fob. If it works from a very short distance but not from further away, it's a classic sign of a weak battery.
4.  **Physical key access:** Remember that your key fob contains a physical key. If your fob completely dies, you can still access your vehicle by pressing the small release button on the side or back of the fob (depending on the model) to slide out the metal key. Use this key to manually unlock the driver's door. This confirms the vehicle's locking mechanism is functional, just not responding to the remote.

This issue is almost never related to diagnostic trouble codes (DTCs). While you can [browse OBD-II codes](/codes) for other vehicle issues, a key fob battery problem is a purely mechanical/electrical fix within the fob itself.

## What You'll Need

Gathering the right tools beforehand will make the replacement process smooth and quick.

*   **New CR2450 3V Lithium Coin Battery:** This is the specific battery type for most 2017 Ford Fusion key fobs. Double-check your owner's manual or the old battery itself to confirm.
*   **Small Flathead Screwdriver or Prying Tool:** A jeweler's screwdriver or a plastic trim removal tool works best to avoid scratching the fob.
*   **Clean Cloth:** To wipe down the fob if needed.

## Step-by-Step Instructions: How to Replace Key Fob Battery 2017 Ford Fusion

Follow these simple steps to replace your key fob battery:

1.  **Remove the Valet Key:** Locate the small button on the side or back of your key fob. Press this button firmly and pull out the metal emergency (valet) key. This key is crucial for manual entry and also provides access to the battery compartment.
2.  **Locate the Opening Slot:** With the valet key removed, you'll see a small slot or indentation where the key was housed, or along the seam of the key fob casing. This is your entry point.
3.  **Carefully Pry Open the Fob:** Insert your small flathead screwdriver or prying tool into the slot. Gently twist or pry to separate the two halves of the key fob casing. Work slowly and carefully to avoid damaging the plastic clips or the internal electronics. The fob should split into two pieces.
4.  **Identify and Remove the Old Battery:** Once open, you'll see the circuit board and the coin battery. Note the orientation of the battery (which side is facing up – usually the positive (+) side). Use your screwdriver or prying tool to gently lift the old CR2450 battery out of its housing. Be careful not to touch the circuit board with your bare hands, as static electricity can cause damage.
5.  **Insert the New Battery:** Take your new CR2450 battery. Ensure you insert it with the positive (+) side facing the same direction as the old battery (usually upwards). Press it firmly into place until it clicks securely.
6.  **Reassemble the Key Fob:** Align the two halves of the key fob casing. Press them firmly together until you hear them snap back into place. Ensure there are no gaps and the casing is securely closed.
7.  **Reinsert the Valet Key:** Slide the metal emergency key back into its slot until it clicks into place.
8.  **Test Functionality:** Stand near your 2017 Ford Fusion and test all the buttons on your key fob: lock, unlock, trunk release, and remote start (if applicable). It should now respond instantly and reliably.

Congratulations! You've successfully replaced your 2017 Ford Fusion key fob battery. For more detailed repair guides for your vehicle, explore our extensive library.

## What to do if the problem persists

If you've replaced the battery and your key fob is still not working, consider these troubleshooting steps:

*   **Check Battery Orientation:** Double-check that the new battery is inserted correctly with the positive (+) side facing the right direction.
*   **Try Another New Battery:** Rarely, a new battery can be faulty. Try a different brand-new CR2450 battery to rule this out.
*   **Inspect for Damage:** Carefully open the fob again and inspect the internal components for any visible damage, corrosion, or loose connections.
*   **Reprogramming (Unlikely but Possible):** Ford key fobs typically do not require reprogramming after a battery change. However, if all else fails, a dealership or automotive locksmith might be able to diagnose a deeper issue or attempt a reprogramming, though this is rare for just a battery swap.
*   **Consult a Professional:** If the issue continues, it might indicate a problem with the key fob's internal electronics or the vehicle's receiver. In this case, it's best to consult a Ford dealership or a qualified automotive locksmith. Explore guides for other [vehicles](/vehicles) or dive deeper into your [Fusion model hub](/vehicles/ford/fusion) for common issues. You can also visit our dedicated [Ford vehicle hub](/vehicles/ford) for more brand-specific information.

## Frequently Asked Questions (FAQ)

### What type of battery does a 2017 Ford Fusion key fob use?
The 2017 Ford Fusion key fob typically uses a **CR2450 3V lithium coin battery**. It's always a good idea to confirm this by checking your owner's manual or the old battery itself when you open the fob.

### How long does a key fob battery last?
Key fob batteries generally last between **3 to 4 years**, depending on usage frequency and environmental factors. If you use your remote start or lock/unlock buttons very frequently, it might drain faster. Your vehicle's "Key Fob Battery Low" warning is a good indicator it's time for a change.

### Do I need to reprogram my key fob after replacing the battery?
No, in most cases, you **do not need to reprogram** your 2017 Ford Fusion key fob after simply replacing the battery. The key fob retains its programming even when the battery is removed. Just replace the battery, reassemble the fob, and it should work immediately.

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**Disclaimer:** *This guide provides general information for educational purposes only and is not a substitute for professional advice from a qualified technician. Always exercise caution when working on your vehicle and consult your owner's manual for specific instructions and safety precautions.*