Anti-Theft - Passive Anti-Theft System (PATS)

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

The passive anti-theft system (PATS) contains the following components:
- anti-theft indicator
- encoded ignition key
- PATS transceiver
- powertrain control module (PCM)

PATS uses radio frequency identification technology to deter a drive-away theft. Passive means that it does not require any activity from the user.

PATS is not compatible with aftermarket remote start systems, which allow the vehicle to be started from the exterior of 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.

PATS uses a specially encoded ignition key. Each PATS key contains a permanently installed electronic device called a transponder. Each transponder contains a unique encrypted identification code out of over 18 billion combinations.

Each PATS key must be programmed into the PCM before it can be used to start the engine. There are special diagnostic repair procedures described in this manual that must be carried out if a new PATS key is necessary.

This system contains a new feature named unlimited key mode. This feature allows a customer to program more than 8 vehicle keys if requested. Each vehicle in unlimited key mode is set up with a special unlimited transponder security key. This allows all the customer vehicles to share the same mechanically cut keys. For an individual customer, any randomly selected security key is acceptable. Refer to Spare Key Programming.

The PATS transceiver module energizes the transponder in the PATS key. The module is located behind the steering wheel column shroud and contains an antenna connected to a small electronics module.

The control functions are 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 engine enable. The PCM initiates the key interrogation sequence when the vehicle ignition switch is in the RUN or START position.

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 anti-theft indicator located in the instrument cluster. Under normal operation, the indicator proves out for 3 seconds when the ignition switch is in the RUN or START position. If there is a PATS problem, this indicator either flashes rapidly or glows steadily when the ignition switch is in the RUN or START position. The PATS also flashes the indicator every 2 seconds with the ignition switch in the OFF position to act as a visual deterrent.

PATS is activated and disables the vehicle from starting if there is:
- an incorrectly encoded PATS key.
- a damaged PATS key.
- an unprogrammed key.
- a non-encoded key (key has no electronics).
- damaged wiring.
- a damaged transceiver.
- a damaged PCM.