Disabling Unlimited Key Mode

WARNING: This page is about a different car, the 2003 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.

Using a diagnostic tool, select instrument cluster from the menu. Follow SECURITY ACCESS to obtain security access. For additional information, Refer to ANTI-THEFT SECURITY ACCESS .
Select DISABLE UNLIMITED KEY MODE.
Select IGNITION KEY CODE ERASE and RESET SERVICE BIT, if applicable.
Disconnect the diagnostic tool and turn the ignition key to OFF
Program in two keys to enable the vehicle.
Program any additional keys using either Key Programming Using Two Programmed Keys or KEY PROGRAMMING USING DIAGNOSTIC EQUIPMENT .