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 - PCM (Powertrain Control Module)





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






Passive Anti-Theft System (PATS)

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 RFR (Remote Functions Receiver) module via a high frequency signal. The RFR (Remote Functions Receiver) 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, a DTC (Diagnostic Trouble Code) is stored in 1 of the 3 modules.

PATS (Passive Anti-Theft System) and the RKE (Remote Keyless Entry) system share operation of several components including the IA (Intelligent Access) key and the RFR (Remote Functions Receiver) 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






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 RFR (Remote Functions Receiver) module and results in the Key not detected message displayed in the message center when the start/stop switch is pressed. However, in the event of 1 of these failures, the IA (Intelligent Access) key can be placed in the backup slot to allow the vehicle to start. If a programmed IA (Intelligent Access) key is in the backup slot when the PATS (Passive Anti-Theft System) transceiver is activated, it activates the IA (Intelligent Access) key and the identification code is sent back to the BCM (Body Control Module). The backup slot is located in the steering column in the same location as a conventional ignition lock cylinder.

No Key Detected Message

The Key not detected message can be displayed in the message center 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.

If a component failure is causing the key not detected message to be displayed, the backup starting method can be used. REFER to Backup Starting.

Key Outside Vehicle Message

The Key outside car message is displayed in the message center when the engine has been started or the ignition is in the ON 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 luggage compartment lid/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 ON 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 10 seconds. After 10 seconds an IA (Intelligent Access) key has to be present to start the engine or transition the ignition out of OFF. If the driver door is opened during the 10-second countdown, the fast restart feature is disabled and an IA (Intelligent Access) key is needed to start the engine again.