2024 Subaru Forester Key Fob Programming Guide

Quick reference

Step-by-step on-board programming

The 2024 Subaru Forester does not support DIY on-board key fob programming for new fobs. Programming requires specialized diagnostic equipment connected to the vehicle's onboard computer. This is typically done by a Subaru dealership or an automotive locksmith.

Why is a scan tool needed?

Modern Subaru vehicles, including the 2024 Forester, utilize a sophisticated immobilizer system that links the key fob's remote functions and the vehicle's engine start function. When a new key fob is introduced, the vehicle's onboard computer (ECU) needs to be updated to recognize the new fob's unique encrypted code. This process requires a scan tool to access the vehicle's security protocols and perform the necessary programming procedures.

Battery replacement

1. Locate the small release button or tab on the side of the key fob. Press it to release the emergency key blade, then pull the blade out.
2. With the emergency key removed, you'll see a small slot or indentation on the side of the fob. Use a small flat-head screwdriver or a coin to gently pry apart the two halves of the key fob casing.
3. Carefully separate the halves to expose the internal circuit board and the battery. Note the orientation of the old battery.
4. Remove the old CR2032 battery. You may need to gently pry it out with a small screwdriver.
5. Insert the new CR2032 battery with the positive (+) side facing up (this is usually the side with text on it).
6. Align the two halves of the key fob casing and firmly press them back together until they click securely.
7. Reinsert the emergency key blade.
8. Test the fob's functions (lock, unlock, trunk, panic) to ensure it's working correctly.

Where to buy a replacement fob

• Subaru Dealership:
  • Pros: Guaranteed genuine OEM part, often comes with programming included, knowledgeable staff.
  • Cons: Most expensive option. Expect to pay anywhere from $250 - $400+ for the fob and programming.
• Automotive Locksmith:
  • Pros: Often more affordable than a dealership, many offer mobile services, can cut and program the key on-site. They typically carry high-quality aftermarket fobs that are fully compatible.
  • Cons: Prices can vary, ensure the locksmith specializes in automotive transponder keys.
  • Ballpark Price: $150 - $300, including the fob, cutting, and programming.
• Online Retailers (Amazon, eBay, specialized key sites):
  • Pros: Potentially the cheapest option for the fob itself.
  • Cons: You're only buying the physical fob; you'll still need to pay for cutting and programming separately. Be extremely careful to verify the FCC ID (WAZP129) and part number (88835SJ000) to ensure compatibility. Many cheap fobs online are low quality or incorrect. If you buy a blank key, you're risking incompatibility and potentially wasting money.
  • Ballpark Price: A blank fob might cost $50 - $100, plus additional costs for cutting and programming (which can negate any savings if you need to pay full price for those services elsewhere).

If on-board programming isn't supported

As established, the 2024 Subaru Forester requires specialized equipment for key fob programming due to its advanced immobilizer system. This means you will need to rely on a professional service.

Cost Expectations:

When budgeting for a new key fob, consider two main costs:

1. The Fob Itself: As detailed above, prices vary significantly based on where you purchase it.
2. Programming and Key Cutting: This is the service fee charged by the dealership or locksmith to link the new fob to your vehicle and cut the emergency key blade. Expect to pay an additional $70 - $150 for these services, on top of the fob's cost.

Immobilizer Transponder: The 2024 Subaru Forester uses an integrated immobilizer transponder chip within the key fob. This chip sends a unique code to the vehicle's engine control unit (ECU) when you try to start the car. If the code doesn't match, the vehicle will not start, even if the key blade physically turns in the ignition. This is a critical security feature, and why programming with a scan tool is essential to ensure both the remote functions and the vehicle's start function are operational.

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