Subaru Key Fob Not Working After Battery Change? Troubleshooting & Solutions

Changing your Subaru key fob battery should be a straightforward task. However, it can be frustrating when your Subaru key fob stops working after a battery replacement. If you’re experiencing this issue, you’re not alone. Many Subaru owners encounter problems with their key fobs after a battery change. This guide from our experts at keyfobx.com will walk you through the common reasons why your Subaru key fob might fail after a battery swap and provide step-by-step solutions to get you back on the road.

Understanding Why Your Subaru Key Fob Might Fail After Battery Replacement

Before assuming the worst, let’s explore the common culprits behind a Subaru key fob malfunction after a battery change. Identifying the cause is the first step towards a solution.

• Incorrect Battery Installation: The most frequent mistake is inserting the battery with the wrong polarity. Key fobs require the battery to be placed in a specific orientation (+ and – sides). A reversed battery will prevent the fob from working.
• Low Quality or Wrong Battery Type: Using a cheap or incorrect battery can also lead to issues. Subaru key fobs typically require a CR2032 battery, especially for newer models. Ensure you are using the correct type and a reputable brand for optimal performance.
• Battery Contact Problems: Sometimes, the metal contacts inside the key fob that connect with the battery can become dirty, bent, or lose their springiness. This can result in poor or no electrical connection even with a new battery.
• Key Fob Programming Loss (Older Models): While less common with modern Subarus, older models might lose their programming when the battery is removed, although this is not typical for a simple battery change.
• Underlying Key Fob Issues: If your key fob was already nearing the end of its lifespan, the battery change might simply highlight an existing problem, such as a failing circuit board or worn-out buttons.

Quick Checks Before Reprogramming or Seeking Help

Before you jump into reprogramming or consider professional help, perform these quick checks to rule out simple fixes:

1. Verify Battery Polarity: Open the key fob and double-check that the battery is installed correctly. Most key fobs have a diagram indicating the correct battery orientation. The positive (+) side usually faces upwards.

2. Check Battery Type and Voltage: Confirm you’ve used the correct battery type (usually CR2032 for newer rectangular fobs). Ensure the new battery is fresh and has sufficient voltage. A battery tester can be helpful, but a new battery from a trusted source should generally be good.

3. Clean Battery Contacts: Examine the metal contacts inside the key fob for dirt or corrosion. Gently clean them with a cotton swab or a soft cloth. If they appear bent, carefully try to adjust them to ensure good contact with the battery.

4. Try a Known Good Battery: If possible, try a different new CR2032 battery from a different pack to rule out a faulty battery.

If these quick checks don’t resolve the issue, and you have an older Subaru (typically with a teardrop-shaped fob), you might need to reprogram your key fob.

How to Reprogram Your Subaru Key Fob (For Older Models)

For older Subaru models with a teardrop-shaped key fob, you might be able to reprogram it yourself. This process involves using an 8-digit code found inside your key fob and a specific sequence of actions in your vehicle.

Important Note: This reprogramming method is generally for older Subaru models. Newer models often require dealership programming. If you are unsure, consult your owner’s manual or contact a Subaru dealership.

Finding Your 8-Digit Subaru Key Fob Programming Code

1. Open the Key Fob: Carefully open the key fob case. You’ll typically find a small notch or area to insert a flathead screwdriver or coin to gently pry it open.

2. Locate the 8-Digit Code: Inside the fob, on the transmitter circuit board, look for one or two series of 8-digit numbers.

3. Record the Code: Write down the first 8-digit number series. This is your programming code.

4. Reassemble the Fob: Carefully put the key fob case back together.

Programming Steps: Entering Your Code

Perform these steps quickly and precisely:

1. Prepare the Vehicle: Sit in the driver’s seat with all doors closed and the vehicle turned off.

2. Unlock Doors and Close Driver’s Door: Open the driver’s side door, unlock all doors using the door button control, and then close the driver’s side door.

3. Ignition Cycle (10 Times): Insert the key into the ignition. Quickly turn the key to the “ON” position (without starting the engine) and then back to “OFF.” Repeat this ten times in rapid succession.

4. Chime and Door Cycle: You should hear a chime from the instrument panel after the tenth cycle. Open and close the driver’s side door again. A second chime should sound, and the dome lights may flash. This indicates programming mode is active (you have approximately 45 seconds).

5. Enter the 8-Digit Code Using Lock/Unlock Buttons:

   • Locate the lock and unlock buttons on the driver’s side door.
   • For each digit in your 8-digit code: Press the “Lock” button the number of times corresponding to the digit, then press the “Unlock” button once.
   • For example, if the first digit is ‘3’, press “Lock” three times, then “Unlock” once. Repeat for all eight digits.

6. Confirmation Chime and Repeat: After entering all eight digits, you should hear an external chime confirming the code entry. Repeat steps 5 to confirm the code was entered correctly. You should hear the vehicle’s locking system engage.

7. Final Steps: Open and close the driver’s door. Press “Lock” or “Unlock” on your key fob. Remove the key from the ignition – you should hear a final chime. Open and close the door one last time. Within about five seconds, test your key fob buttons.

If the programming sequence is successful, your Subaru key fob should now be working.

Battery Replacement for Newer Subaru Key Fobs (Rectangle Shape)

For newer, rectangular Subaru key fobs, the battery replacement process is slightly different but still user-friendly. These fobs typically use a CR2032 battery.

1. Remove the Emergency Key: On the back of the key fob, locate and push the small silver tab or button to release and slide out the mechanical emergency key.

2. Open the Fob Casing: Insert the tip of the emergency key or a small flathead screwdriver into the slot exposed after removing the key. Gently twist to pry open the key fob casing.

3. Access and Replace Battery: Locate the battery (often on the circuit board side). Carefully remove the old battery and insert the new CR2032 battery, ensuring the correct polarity (+ side up).

4. Reassemble the Fob: Snap the key fob casing back together until it clicks securely. Re-insert the emergency key.

When to Seek Professional Help

If you’ve tried the troubleshooting steps and reprogramming (for older models) and your Subaru key fob still isn’t working after a battery change, it might be time to seek professional assistance.

• Dealership Service: Your local Subaru dealership service center is equipped to diagnose and resolve key fob issues, especially for newer models that require specialized programming tools.
• Automotive Locksmith: A qualified automotive locksmith can also often help with key fob programming and repairs, potentially at a lower cost than a dealership.

Key Takeaway: While a non-functioning key fob after a battery change can be inconvenient, it’s often resolvable with simple troubleshooting or reprogramming steps. By following this guide, you can confidently address common issues and get your Subaru key fob working again. If you encounter persistent problems, don’t hesitate to contact a professional for expert assistance.