Encoded Passive Anti-Theft System (PATS) Keys

WARNING: This page is about a different car, the 2011 Mercury Milan, 2011 Lincoln MKZ, and 2011 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

PATS uses a special ignition key, called an IKT key that is larger than a conventional ignition key. It contains a permanently installed electronic device called a transponder and also has the Remote Keyless Entry (RKE) transmitter integrated into the keyhead. Each transponder contains a unique encrypted identification code which is one of a very large number of combinations. The addition of this transponder to the key makes it an "encoded" key. The PATS portion of the IKT key does not require batteries and should last the lifetime of the vehicle. The transmitter portion of the IKT key has a battery. Each PATS key must be programmed into the IPC before it can be used to start the vehicle. A maximum of 4 IKT keys can be programmed to start the vehicle and also operate the RKE functions. If more than 4 IKT keys are programmed, the RKE portion of the additional IKT keys do not operate and the SJB sets DTC B1138, and the IPC sets DTC B109E:42 (both DTCs indicate a memory full condition). These additional keys start the vehicle, but cannot operate the RKE system, as only the first 4 IKT keys programmed have that RKE functionality. If additional PATS keys are desired, a standard PATS key (a non-IKT key) can be used. There are specific general procedures described in this service information that must be carried out if a new PATS key is necessary. Refer to INTEGRATED KEYHEAD TRANSMITTER (IKT) KEY PROGRAMMING USING DIAGNOSTIC EQUIPMENT or KEY PROGRAMMING USING TWO PROGRAMMED KEYS in this service information.