It could use the same acronym, but is perimeter anti-theft the same as PATS? No, PATS, which stands for passive anti-theft systems, is a system that is designed to identify the key, and was discussed in the July 2007 issue of Underhood Service. Perimeter anti-theft is a system designed to identify unauthorized vehicle entry. There are two main types of these systems from Ford — a dealer-installed version and a factory-installed version. We’ll just discuss the factory-installed version.

The factory perimeter anti-theft is an extension of the remote keyless entry system. Depending on the year and model of the vehicle, the remote keyless entry system may be controlled by a dedicated Remote Anti-theft Personality module (RAP), a Body Security Module (BSM)/Central Security Module (CSM) or a Vehicle Security Module (VSM).

RAP System
The RAP module is the older method of keyless entry and perimeter anti-theft, spanning a time line of the late ’90s to early 2000s. Let’s discuss the RAP module system first to gain a general system understanding to build upon for the others.

On Expeditions and F-Series, the RAP module can be seen under the driver’s side of the dash against the firewall. Usually, the part number tag of the RAP module will also contain the five-digit code for the key pad on the door.

In Photo 1, you can see the factory door pad code is 75335 for this vehicle. T...