With Intelligent Access (IA)

Anti-Theft - With Intelligent Access (IA)

Principles of Operation

Push Button Start Components

Passive Start Antennas

There are three passive start antennas. The passive start antennas are hardwired to the Remote Function Actuator (RFA) module and, when activated by the RFA module, they transmit a low frequency signal that activates an Intelligent Access (IA) key.

Passive Anti-Theft System (PATS)/Backup Transceiver

The PATS/backup transceiver is used as a backup device. If the vehicle fails to start conventionally, an IA key can be held in close proximity to the transceiver to allow the vehicle to start. The transceiver is wired to the RFA module and when activated it sends out a signal to activate an IA key. Once the key is activated, it sends a signal back to the transceiver which is then sent to the RFA module.

Remote Functions Receiver (RFR) Module

The Remote Functions Receiver (RFR) module is hardwired to the RFA module and is a receiving antenna that receives the high frequency signals from an IA key. It also receives the signals from an Remote Keyless Entry (RKE) command.

IA Key

The IA receives the low frequency signals from the passive start antennas. When the IA key is activated by one of the low frequency signals, it sends out a high frequency signal that is received by the RFR module. The IA key also contains a key blade that is used to enter the vehicle as a backup.

Start/Stop Switch

The start/stop switch is a momentary contact switch that is hardwired to the RFA module. When the switch is pressed, it signals the RFA module that there is a request to either switch the ignition on or start the engine.

Push Button Start Operation





The Passive Anti-Theft System (PATS) function is controlled by the RFA module and PCM.

When the start/stop switch is pressed, the RFA module initiates the key initialization sequence by activating the 3 interior IA passive start antennas. Each passive start antenna transmits a low frequency signal approximately 1 m (3 ft) radius of each antenna. If an IA key is within range of 1 of the 3 interior passive start antennas, the IA key is activated. Once the IA key is activated, it sends the PATS identification code to the Remote Functions Receiver (RFR) module via a high frequency signal. The RFR module interprets the high frequency signal from the IA key and sends the information to the RFA module over a dedicated network. If the RFA module determines that a programmed IA key is inside the vehicle, it allows the ignition to be transitioned out of off. When the ignition is turned on and the PCM initializes, the RFA module and the PCM exchange their IDs over the High Speed Controller Area Network (HS-CAN). If the RFA module receives a valid key code and the correct ID from the PCM, PATS is enabled and allows the engine to start. If PATS disables the engine from starting, the anti-theft indicator in the IPC flashes rapidly.

PATS and the RKE system share the operation of several components including the IA key and the RFR module. If there is a concern with either of these components, both PATS and the RKE system are affected. Refer to Handles, Locks, Latches and Entry Systems Testing and Inspection for information on the RKE and IA features.

The RFA module also controls the ignition modes and in conjunction with the PCM controls the starting system. If there is a concern with starting system or the ignition modes, and PATS has been eliminated as the cause, refer to Starting System Testing and Inspection for a starting system concern or Steering Column Switches Testing and Inspection for the ignition modes.

Backup Starting

The vehicle can experience a PATS no start if there is a failure of any passive start antenna, the battery in the IA key, or the RFR module. However, in the event of one of these failures, the IA key can be placed next to the PATS/backup transceiver (located in the steering column) to allow the vehicle to start. If a programmed IA key is near the steering column shroud when the PATS/backup transceiver is activated, it activates the IA key and the identification code is sent back to the RFA module.

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 no-start if the IA key is within a few inches of the charger. If a concern is observed, move the IA 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. They are located in the front of the floor console, in the rear of the floor console, and behind the rear lower seat cushion. When activated, each antenna sends out a low frequency signal with an approximate range of 1 m (3 ft). A programmed IA key must be in range of 1 of the 3 antennas for PATS to operate.

If an IA 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 key is located in one of these areas and there is a no-start condition, move the IA key out of the area and attempt to start the vehicle. If the key is outside the range of a passive start antenna, KEY NOT DETECTED is displayed in the Front Control/Display Interface Module (FCDIM).

Key Outside Vehicle Message

The KEY OUTSIDE VEHICLE message is displayed in the FCDIM when the engine has been started or the ignition is in the RUN mode and an IA key is no longer detected inside the vehicle. The RFA module activates all passive start antennas to search the inside of the vehicle for an IA key anytime a door or luggage compartment lid/liftgate is opened and then closed. This strategy prevents the IA key from being separated from an already running vehicle. If an IA 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 re-started without an IA key present inside the vehicle for approximately 10 seconds. After 10 seconds an IA 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 key is needed to start the engine again.

Passive Anti-Theft System (PATS) PIDs

The Passive Anti-Theft System (PATS) PIDS are a useful tool when diagnosing a PATS concerns.