Spare Key Programming

1998 Mercury Mountaineer 5.0 P, AWDSECTION Spare Key Programming
WARNING: This page is about a different car, the 1997 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Replacement PATS modules require only one key to be programmed before allowing vehicle to start. If PATS module is replaced, any additional keys must be programmed. PATS module has capacity to store programming for 16 keys.

Cycle ignition switch from RUN to OFF position with a programmed key. Within 15 seconds after this cycle, insert a new encoded key into ignition switch and turn key to RUN or START position. If programming was successful, THEFT indicator light will be on for 2 seconds and PATS module will enable vehicle to start.

If programming was not successful, THEFT indicator will flash for one minute if no key code is received, key is damaged or a non-encoded key is being used. If this happens, use a new key and repeat programming procedure. THEFT indicator light will flash for 15 minutes if key code is received but vehicle is disabled. If this happens, repeat programming procedure.

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.