Anti-Theft - Passive

ANTI-THEFT - PASSIVE ANTI-THEFT SYSTEM (PATS)

The passive anti-theft system (PATS) uses radio frequency identification
technology to deter a driveaway theft. Passive means that it does not require any activity from the user.

The PATS uses a specially encoded ignition key. Each PATS key contains a
permanently installed electronic device called a transponder. Each transponder contains a unique electronic identification code, with over 72 million billion combinations.

Each PATS key must be programmed into the vehicle powertrain control module (PCM) before it can be used to start the engine. Refer to general procedures.

The PATS key is larger than a traditional ignition key. The PATS key does not require batteries and should last the life of the vehicle.

The transceiver module communicates with the PATS key. This module is located in the steering column attached to the ignition cylinder housing. During each vehicle start sequence, the transceiver module reads the PATS key identification code and sends the data to the PCM. The PCM validates the code as correct and enables the starter.

The control function is contained in the PCM. This module carries out all of the PATS functions such as receiving the identification code from the PATS key and controlling the starter enable signal. The PCM initiates the key interrogation sequence when the PATS key is inserted in the ignition switch and when the switch is turned to RUN or START.

The PCM enables or disables the engine. All elements of PATS must be functional before the engine is allowed to start. If any of the components are not working correctly, the vehicle will not start.

PATS uses a visual theft indicator. This indicator will prove out for 3 seconds when the ignition switch is turned to RUN or START under normal operation. If there is a PATS problem, this indicator will either flash rapidly or glow steadily (for more than 3 seconds) when the ignition switch is turned to RUN or START.

The PATS is not compatible with non-Ford approved aftermarket remote start systems, which allow the vehicle to be started from outside the vehicle. These systems may reduce the vehicle security level, and also may cause no-start issues. Remote start systems must be removed before investigation of PATS-related no-start issues.

PRINCIPLES OF OPERATION-PATS

The passive anti-theft system (PATS) is initiated by turning the key to the ON or START position. When a valid PATS key is turned to the ON or Run position the PCM querries the PATS transceiver over circuit 1215 (WH/LG). The transceiver then reads the key code and sends the code to the PCM over circuit 1216 (OG/LB). The PCM then validates the read code against stored authorized keys. If the codes match the PCM then enables the starter using circuit 1419 (LG/YE). If the codes do not match the starter will remain disabled and the vehicle will not start. The PCM will then flash or turn on the anti-theft warning indicator light to indicate the fault.