Replace with Correct 40-bit or 80-bit Transponder Chip

1. Identify the specific transponder requirement for your vehicle by checking the part number on your original key head (e.g., 98AG15K601AC) and cross-referencing it with Ford PATS legacy specifications to determine if the vehicle requires a 40-bit or 80-bit ID63 chip.

2. Procure a replacement transponder chip that explicitly matches the required bit-depth formatting identified in the previous step.

3. Use a professional-grade immobilizer programmer (such as Xhorse VVDI Key Tool, ThinkCar G3, or Autel KM100) or FORScan software with an OBDLink EX cable to clear existing key data and initiate the new programming sequence.

4. Insert the new, correctly formatted chip into the key housing and proceed with the diagnostic tool's 'Program Key' function, ensuring the handshake sequence completes without the previous 'Programming Failed' error.

5. Verify the fix by starting the vehicle and observing the dashboard security light; the light should extinguish, confirming the ECU has accepted the new bit-depth formatting.

Safety Precaution: Ensure no other electronic keys or transponder chips are in the vehicle cabin during the programming process to avoid signal interference that could cause the module to lock.

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