Antitheft and Alarm Systems: Description and Operation

Anti-Theft

NOTE: The Passive Anti-Theft System (PATS) is available on this vehicle as an option. The vehicle must be ordered with or without PATS per the customer. It is not a dealer-installed option.

NOTE: If a new Instrument Cluster (IC) or the PCM (or both) is installed, the parameters MUST be reset in both modules or the vehicle experiences a PATS no-start. This occurs even if the vehicle is not equipped with PATS. Refer to Passive Anti-Theft System (PATS) Parameter Reset Passive Anti-Theft System (PATS).

The PATS consists of the following components:

- Anti-theft indicator (located in the IC)
- Encoded ignition Integrated Keyhead Transmitter (IKT) PATS key(s) (the key contains a removable transponder and a Remote Keyless Entry (RKE) transmitter)
- Encoded (the key contains a transponder) ignition PATS keys (when not equipped with RKE)
- PATS transceiver
- IC
- PCM

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

The vehicle is equipped with 2 IKT PATS keys (vehicles equipped with RKE). The IKTs operate as a standard PATS key with an RKE transmitter incorporated into the keyhead. The IKTs require batteries for the RKE transmitter to operate. A maximum of 4 IKT keys can be programmed to operate the vehicle. If more than 4 IKT keys are programmed (up to 8 keys in total), the RKE portion of the additional keys do not operate. These additional keys start the vehicle, but cannot operate the RKE system. If additional PATS keys are desired, a standard PATS key (a non-IKT key) can be used.

For vehicles not equipped with RKE, the vehicle is equipped with 2 non-IKT keys. Only 8 keys can be programmed into the PATS. For the purposes, the PATS portion of the IKT key is referred to as a PATS key.

Passive Anti-Theft System (PATS) Function

The PATS function is controlled by the IC. The PATS uses the IC to carry out all of the PATS functions such as receiving the identification code from the PATS key, issuing a signal to the PCM to control the starter and fuel injectors enable, and initiating the key interrogation sequence when the ignition key is turned to the ON or START position. Because of the interaction between the IC and the PCM, there are parameters that must be set if the IC or the PCM (or both) are replaced. Refer to Passive Anti-Theft System (PATS) Parameter Reset Passive Anti-Theft System (PATS). If the IC must be replaced for any reason (PATS concerns or an IC concern), the PATS keys must also be programmed into the new IC. Refer to Key Programming Using Diagnostic Equipment Using Diagnostic Equipment. All elements of PATS must be functional before the vehicle starts. If any of the components are not working correctly, the vehicle cannot start. After the PATS keys are programmed into the new IC, the RKE transmitter needs to be programmed into the GEM. If programming an IKT key, the PATS key and the RKE transmitter are programmed to the vehicle in 2 distinctly different procedures on this vehicle.

PATS is not compatible with aftermarket remote start systems, which allow the vehicle to be started from the exterior of the vehicle. These systems can reduce the security of the vehicle, and also may be the cause of no-start concerns. Remote start systems must be removed from the vehicle before any PATS-related no-start concerns are investigated.