System Operation

Passive Anti-Theft System (PATS) - with Intelligent Access (IA)

System Operation

System Diagram





Network Message Chart

Module Network Input Messages - BCM (Body Control Module)





Module Network Input Messages - RFA (Remote Function Actuator) Module





Module Network Input Messages - PCM (Powertrain Control Module)






Passive Anti-Theft System (PATS)

NOTE: The IA (Intelligent Access) feature is a programmable parameter and can be enabled/disabled with a scan tool. If the feature is disabled, the IA (Intelligent Access) feature to enter the vehicle and passive starting will be inoperative. To start the vehicle, the IA (Intelligent Access) key has to be placed in the backup slot.

The PATS (Passive Anti-Theft System) function is controlled by the RFA (Remote Function Actuator) module, BCM (Body Control Module), and PCM (Powertrain Control Module).

When the start/stop switch is pressed, the RFA (Remote Function Actuator) module initiates the key initialization sequence by activating the 3 interior passive start antennas. Each passive start antenna transmits a low frequency signal approximately 1 m (3 ft) radius of each antenna. If an IA (Intelligent Access) key is within range of 1 of the 3 interior passive start antennas, the IA (Intelligent Access) key is activated. Once the IA (Intelligent Access) key is activated, it sends the PATS (Passive Anti-Theft System) identification code to the TPM (Tire Pressure Monitor) module via a high frequency signal. The TPM (Tire Pressure Monitor) module interprets the high frequency signal from the IA (Intelligent Access) key and sends the information to the RFA (Remote Function Actuator) module over a dedicated network. If the RFA (Remote Function Actuator) module determines that a programmed IA (Intelligent Access) key is inside the vehicle, it communicates with the BCM (Body Control Module) over the MS-CAN (Medium Speed Controller Area Network) and allows the ignition to be transitioned out of off. When the ignition is turned on and the modules initialize, the RFA (Remote Function Actuator) module, BCM (Body Control Module), and the PCM (Powertrain Control Module) exchange their identifications over the MS-CAN (Medium Speed Controller Area Network) and HS-CAN (High Speed Controller Area Network). If each of the modules receive the correct identification from each other, PATS (Passive Anti-Theft System) is enabled and allows the engine to start. If PATS (Passive Anti-Theft System) disables the engine from starting, STARTING SYSTEM FAULT is displayed in the message center and a DTC is stored in one of the 3 modules.

PATS (Passive Anti-Theft System) and the RKE (Remote Keyless Entry) system share the operation of several components including the IA (Intelligent Access) key and the TPM (Tire Pressure Monitor) module. If there is a concern with either of these components, both PATS (Passive Anti-Theft System) and the RKE (Remote Keyless Entry) system are affected. REFER to Handles, Locks, Latches and Entry Systems - with Intelligent Access (IA) for information on the RKE (Remote Keyless Entry) and IA (Intelligent Access) features.

The RFA (Remote Function Actuator) module in conjunction with the BCM (Body Control Module) controls the ignition modes and in conjunction with the PCM (Powertrain Control Module) controls the starting system.

PATS (Passive Anti-Theft System) PIDs (Parameter Identifications)

In conjunction with DTCs (Diagnostic Trouble Codes), the PATS (Passive Anti-Theft System) PIDs (Parameter Identifications) are a useful tool when diagnosing PATS (Passive Anti-Theft System) concerns.

Module PID Chart - BCM (Body Control Module)





Module PID Chart - RFA (Remote Function Actuator) Module

NOTE: The RFA (Remote Function Actuator) module PATS (Passive Anti-Theft System) PIDs (Parameter Identifications) do not actively display their current state. They only display the correct state when the ignition is turned to the ON mode after the ignition has been OFF for several minutes. The correct PID (Parameter Identification) value is only available for a brief window of time before the PID (Parameter Identification) becomes inactive.





Backup Starting

The vehicle can experience a PATS (Passive Anti-Theft System) no start if there is a failure of any passive start antenna, the battery in the IA (Intelligent Access) key, or the TPM (Tire Pressure Monitor) module and results in the NO KEY DETECTED message displayed in the message center when the start/stop switch is pressed. However, in the event of one of these failures, the IA (Intelligent Access) key can be placed in the backup slot to allow the vehicle to start. The IA (Intelligent Access) key should be placed in the backup slot with the buttons facing outwards and the key ring up. If a programmed IA (Intelligent Access) key is in the backup slot when the backup transceiver is activated, it activates the IA (Intelligent Access) key and the identification code is sent back to the RFA (Remote Function Actuator) module. The backup slot is located in the front center of the floor console.

No Key Detected Message

The NO KEY DETECTED message can be displayed in the message center in either of the following scenarios.

When the ignition is off and the start/stop switch is pressed and a programmed IA (Intelligent Access) key is not detected inside the vehicle.

When the engine has been started or the ignition is in the RUN mode and an IA (Intelligent Access) key is no longer detected inside the vehicle. The RFA (Remote Function Actuator) module activates all passive start antennas to search the inside of the vehicle for an IA (Intelligent Access) key any time a door or liftgate is opened and then closed or the vehicle is in motion. This strategy prevents the IA (Intelligent Access) key from being separated from an already running vehicle. If an IA (Intelligent Access) key is no longer in the vehicle, the ignition remains in RUN and the engine continues to run. If the start/stop switch is pressed to turn the ignition off, the engine can be restarted without an IA (Intelligent Access) key present inside the vehicle for approximately 20 seconds, during that time RESTART NOW OR KEY IS NEEDED is displayed in the message center. After 20 seconds an IA (Intelligent Access) key has to be present to start the engine or transition the ignition out of off.