Passive Anti-Theft System (PATS) - with Intelligent Access (IA)
Passive Anti-Theft System (PATS) - with Intelligent Access (IA)
Component Location
Overview
PATS (Passive Anti-Theft System) protects the vehicle from theft by preventing the ignition from turning on or the engine from starting unless a programmed IA (Intelligent Access) key is detected inside the vehicle. PATS (Passive Anti-Theft System) cannot disable an already running engine.
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.
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.
Component Description
Passive Start Antennas
There are 3 passive start antennas. The passive start antennas are hardwired to the RFA (Remote Function Actuator) module and when activated by the RFA (Remote Function Actuator) module they transmit a low frequency signal that activates an IA (Intelligent Access) key.
Interior Passive Start Antenna Ranges
NOTE: Some brands/types of mobile phone or laptop computer chargers may cause interference that could lead to a PATS (Passive Anti-Theft System) no-start if the IA (Intelligent Access) key is within a few inches of the charger and the NO KEY DETECTED message is displayed in the message center. If a concern is observed, move the IA (Intelligent Access) key away from the charger and attempt to start the vehicle.
There are 3 passive start antennas that are used solely for the purpose of starting the vehicle. When activated, each antenna sends out a low frequency signal with an approximate range of 1 m (3 ft). A programmed IA (Intelligent Access) key must be in range of 1 of the 3 antennas for PATS (Passive Anti-Theft System) to operate.
If an IA (Intelligent Access) key is placed in the far outside edges of the interior, like above a sun visor or in a door map pocket, the vehicle might experience a no-start. If the IA (Intelligent Access) key is located in one of these areas and there is a no-start condition, move the IA (Intelligent Access) key out of the area and attempt to start the vehicle. If the key is outside the range of a passive start antenna, NO KEY DETECTED is displayed in the message center.
Backup Transceiver
The backup transceiver is used as a backup device. If the vehicle fails to start conventionally, an IA (Intelligent Access) key can be placed in the backup slot to allow the vehicle to start. The backup transceiver is located next to the slot and activates any IA (Intelligent Access) key that is placed in the slot. The transceiver is wired to the RFA (Remote Function Actuator) module and when activated it sends out a signal to activate an IA (Intelligent Access) key. Once the key is activated, it sends a signal back to the transceiver which is then sent to the RFA (Remote Function Actuator) module.
Intelligent Access (IA) Key
The IA (Intelligent Access) key incorporates both the PATS (Passive Anti-Theft System) and the RKE (Remote Keyless Entry) RKE (Remote Keyless Entry) transmitter functions in a single device. The IA (Intelligent Access) key must be located inside the vehicle for engine starting and on the outside for IA (Intelligent Access) features. During key programming procedures, the PATS (Passive Anti-Theft System) and RKE (Remote Keyless Entry) transmitter of an IA (Intelligent Access) key are both programmed into the RFA (Remote Function Actuator) module. The RFA (Remote Function Actuator) module accepts programming of up to 4 IA (Intelligent Access) keys. REFER to Key Programming Using Diagnostic Equipment Key Programming Using Diagnostic Equipment or REFER to Key Programming Using Two Programmed Keys Key Programming Using Two Programmed Keys for the key programming procedures.
The IA (Intelligent Access) key receives the low frequency signals from the passive start antennas. When the IA (Intelligent Access) key is activated by one of the low frequency signals, it sends out a high frequency signal that is received by the TPM (Tire Pressure Monitor) module. The IA (Intelligent Access) key also contains a key blade that is used to enter the vehicle as a backup.
Tire Pressure Monitor (TPM) Module
The TPM (Tire Pressure Monitor) module has a dedicated power and ground. It communicates all IA (Intelligent Access) and RKE (Remote Keyless Entry) information to the RFA (Remote Function Actuator) module through a dedicated single circuit network. The TPM (Tire Pressure Monitor) module is a receiving antenna that receives the high frequency signals from an IA (Intelligent Access) key. It also receives the signals from a RKE (Remote Keyless Entry) command.
Start-Stop Switch
The start/stop switch is a momentary contact switch that is hardwired to the RFA (Remote Function Actuator) module, BCM (Body Control Module), and the PCM (Powertrain Control Module). When the switch is pressed, it signals the RFA (Remote Function Actuator) module, BCM (Body Control Module), and the PCM (Powertrain Control Module) that there is a request to either switch the ignition on or start the engine. The start/stop switch is connected to both the RFA (Remote Function Actuator) module and BCM (Body Control Module) as a backup in case of a failure. If there is a circuit failure to either module from the start/stop switch, the modules communicate the start/stop switch request to each other over the MS-CAN (Medium Speed Controller Area Network) .
Remote Function Actuator (RFA)
The RFA (Remote Function Actuator) module is responsible for obtaining the IA (Intelligent Access) key data. It uses the passive start antennas and the TPM (Tire Pressure Monitor) module to receive the IA (Intelligent Access) key data. The RFA (Remote Function Actuator) module receives direct input from the TPM (Tire Pressure Monitor) module over a dedicated single wire network and is hardwired to the passive start antennas. The RFA (Remote Function Actuator) module communicates the IA (Intelligent Access) key data with the BCM (Body Control Module) over the MS-CAN (Medium Speed Controller Area Network).
The IA (Intelligent Access) keys are programmed to the RFA (Remote Function Actuator) module, and the RFA (Remote Function Actuator) module contains a unique ID that is checked by the BCM (Body Control Module).
If the RFA (Remote Function Actuator) module is replaced, at least two keys must be programmed to it and a parameter reset with the BCM (Body Control Module) must be performed to enable PATS (Passive Anti-Theft System).
Body Control Module (BCM)
The BCM (Body Control Module) is responsible for checking the identifications from both the RFA (Remote Function Actuator) module and the PCM (Powertrain Control Module). It also controls the ignition states and determines if the engine should be started or turned off depending upon input from the start/stop and brake switches and if a programmed IA (Intelligent Access) key is inside the vehicle. The RFA (Remote Function Actuator) module sends a MS-CAN (Medium Speed Controller Area Network) message to the BCM (Body Control Module) indicating if a programmed IA (Intelligent Access) key is inside the vehicle.
If the BCM (Body Control Module) is replaced, the two parameter reset procedures must be performed to enable PATS (Passive Anti-Theft System). The two parameter reset procedures are between the BCM (Body Control Module) and RFA (Remote Function Actuator) module, and the BCM (Body Control Module) and PCM (Powertrain Control Module).