Anti-Theft - Passive Anti-Theft System (PATS)

Anti-Theft

Principles of Operation

NOTE: Replacement of the backup transceiver, the Remote Functions Receiver (RFR) module, or any of the Intelligent Access (IA) passive start antennas does not require the IA (Intelligent Access) keys to be programmed into the Remote Function Actuator (RFA) module again. If the RFA (Remote Function Actuator) module or the PCM is being replaced, the parameters must be reset in both modules or the vehicle experiences a PATS (Passive Anti-Theft System) no-start. Refer to Passive Anti-Theft System (PATS) Parameter Reset - Intelligent Access (IA) .

NOTE: A minimum of 2 IA (Intelligent Access) keys must be programmed into the RFA (Remote Function Actuator) module before the vehicle can start.

Passive Anti-Theft System (PATS) Operation

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

When the start/stop button and/or the brake pedal is pressed, the RFA (Remote Function Actuator) module initiates the key interrogation sequence by activating the 3 interior IA (Intelligent Access) passive start antennas. Each passive start antenna sends out 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 allows the ignition to be transitioned out of the OFF mode. If the operator requests the engine to start, a signal is sent to the PCM over the High Speed Controller Area Network (HS-CAN) to allow the fuel injectors and starter to operate.

If the vehicle has a failure of any passive start antenna, the battery in the IA (Intelligent Access) key, or the RFR (Remote Functions Receiver) module, the vehicle can experience a PATS (Passive Anti-Theft System) no-start. However, in the event of one of these failures, the IA (Intelligent Access) key can be placed in the backup slot (located in the center console) to allow the vehicle to start. The backup transceiver is located next to the backup slot and activates an IA (Intelligent Access) key if it is placed in the slot. The backup transceiver is hardwired to the RFA (Remote Function Actuator) module and when it is activated, sends out a low frequency signal that only travels 77 mm (3.031 in). 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 through the backup transceiver.

The RFA (Remote Function Actuator) module activates all passive start antennas to search the inside of the vehicle for an IA (Intelligent Access) key anytime a door or liftgate is opened or closed. This strategy is used to prevent the IA (Intelligent Access) key from being separated from an already running vehicle.

PATS (Passive Anti-Theft System) is active only for a few seconds when the vehicle is starting. It is not a PATS (Passive Anti-Theft System) concern if the vehicle stalls after it has been running for a minimum of 3 seconds. PATS (Passive Anti-Theft System) cannot disable a running vehicle.

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 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 Doors, Hood and Trunk &/or Locks for information on the RKE (Remote Keyless Entry) and IA (Intelligent Access) features.

The RFA (Remote Function Actuator) module also controls the ignition modes and in conjunction with the PCM controls One-Touch Integrated Start (OTIS). If there is a concern with OTIS (One-Touch Integrated Start) or the ignition modes, and PATS (Passive Anti-Theft System) has been eliminated as the cause, refer to Starting System for OTIS (One-Touch Integrated Start) or Steering Column for the ignition modes.

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. 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. They are located in the front of the floor console, in the rear of the floor console, and under the liftgate scuff trim panel below the liftgate striker. 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.

There are a few areas within the vehicle that are out of reach of the passive start antennas and can cause a PATS (Passive Anti-Theft System) no-start if the IA (Intelligent Access) key is located in these areas:

- Far outside edges of the visors (between the visors and the headliner)

- Far outside edges of the bottom of the windshield (interior side of the windshield)

- Far corners of the rear seat

- Inside the overhead console

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.

Passive Anti-Theft System (PATS) PIDs

Monitoring the PATS (Passive Anti-Theft System) PIDs can be very useful in determining which diagnostic steps to follow. Viewing the MASTERKEY PID (Master Key, verifies if the key is programmed) (with both keys) determines if the key is a programmed key and also proves-out the backup transceiver (if used), the passive start antenna that is being used (the one closest to the IA (Intelligent Access) key), the RFR (Remote Functions Receiver) module, the circuitry and the RFA (Remote Function Actuator) module. It is important to note that the MASTERKEY PID can only be read with the ignition in the ON mode. A master key is any key that is programmed into the RFA (Remote Function Actuator) module. Viewing the MIN_KEYS PID (Minimum Keys, minimum number of keys necessary to start) (this PID does not change) indicates the minimum number of keys that must be programmed into the RFA (Remote Function Actuator) module in order for the vehicle to start. There must be at least 2 keys programmed into the RFA (Remote Function Actuator) module in this type of PATS (Passive Anti-Theft System) before the vehicle starts. Viewing the N_KEYCODE PID (Number of Keys Programmed, number of keys that are programmed) determines if the minimum number of keys have been programmed into the RFA (Remote Function Actuator) module. If the N_KEYCODE PID reads 0 or 1, additional key(s) need to be programmed into the RFA (Remote Function Actuator) module in order to meet the minimum of 2 keys. If the N_KEYCODE PID reads 1, and the MASTERKEY PID reads Present (the ignition must be in the ON mode for this PID to read correctly), that particular key is already programmed into the RFA (Remote Function Actuator) module.

When the parameters in the RFA (Remote Function Actuator) module are reset, it clears (erases) the PCM_ID PID from the RFA (Remote Function Actuator) module. A PCM parameter reset causes the PCM to send a PCM identifier to the RFA (Remote Function Actuator) module that is necessary for the system to operate. Make sure to cycle the ignition at least once, then switch the ignition to the ON mode, making an attempt to start the vehicle for 3-5 seconds before attempting more procedures. If only a PCM parameter reset occurs (or only an RFA (Remote Function Actuator) module parameter reset occurs), the ID stored in the RFA (Remote Function Actuator) module does not match the ID being sent by the PCM, and can cause a PATS (Passive Anti-Theft System) -related no-start. Carry out the parameter reset, and do not cycle the key until after the parameter reset selection has been highlighted, and the Integrated Diagnostic System (IDS) on-screen instructions have been followed. The IDS (Integrated Diagnostic System) then resets the parameters in both the RFA (Remote Function Actuator) module and the PCM at the same time.

If the PCM_VFY PID reads No, the PATSENABL PID reads Disabled, the N_KEYCODE PID reads 1 and the MASTERKEY PID reads Present (the ignition must be in the ON mode for this PID to read correctly), or if the N_KEYCODE PID reads 0 and the MASTERKEY PID reads Not Present (the ignition does not transition to ON with no keys programmed), a minimum of 2 keys need to be programmed into the RFA (Remote Function Actuator) module. Refer to Key Programming Using Diagnostic Equipment - Intelligent Access (IA) .

If the PCM_ID PID (PCM ID is stored) reads Stored, the RFA (Remote Function Actuator) module has a PCM ID stored. If it reads Not Stored, a parameter reset of the PCM may resolve this concern. If the PCM_VFY PID (PCM Verify) reads No, the PATSENABL PID (PATS enable status) reads Disabled, the N_KEYCODE PID reads 2 or more and the MASTERKEY PID reads Present (the ignition must be in the ON mode for this PID to read correctly), the RFA (Remote Function Actuator) module, and the PCM need to have their parameters reset. Refer to Passive Anti-Theft System (PATS) Parameter Reset - Intelligent Access (IA) .

Cranking Factor PIDs

The Crk_Fact_B1 PID (Cranking Factor B1, Start/Stop switch circuit 1) or the Crk_Fact_B2 PID (Cranking Factor B2, Start/Stop switch circuit 2) must read YES, but it is only necessary for one of them to read YES as they are redundant circuits. The start/stop switch still operates using the backup circuit, but if the second circuit should also fail, the start/stop switch cannot operate. for diagnosis of the start/stop switch.

The Crk_Fact_Neu PID (Cranking Factor Neutral, vehicle is in neutral) or the Crk_Fact_Pk PID (Cranking Factor Park, vehicle is in park) must read YES in order to start the vehicle. Both of them cannot read YES, only one of them reading YES is necessary for the vehicle to start.

Spare Key Status PID

The SPAREKEY PID (Spare Key Status, spare key programming status) is defaulted to ENABLE. With the SPAREKEY PID displaying ENABLE, the RFA (Remote Function Actuator) module accepts more than 2 keys (up to a maximum of 4) being programmed into the RFA (Remote Function Actuator) module using the Key Programming Using Two Programmed Keys - Intelligent Access (IA) procedure. The SPAREKEY PID can be toggled to DISABLE if the customer wants to disable the customer spare key programming function. To enable or disable the spare key feature, refer to Key Programming Switch State Control - Intelligent Access (IA) . This switch state control does not affect the Key Programming Using Diagnostic Equipment - With Intelligent Access (IA) procedure.

NOTE: The MASTERKEY PID cannot read accurately until the ignition is on. With the ignition in the off state, it always reads Not Present.

In summary, the PATS (Passive Anti-Theft System) PIDs and their correct state in order for the vehicle to start are:

- Crk_Fact_B1 or Crk_Fact_B2 must read YES (preferably both should read YES, but vehicle starts with only one reading YES) (only reads YES with the Start/Stop button pressed).

- Crk_Fact_Brk must read YES (only reads YES with the brake pedal pressed)

- Crk_Fact_Neu must read YES (only reads YES if the vehicle transmission is in NEUTRAL (N) and Crk_Fact_Pk is NO)

- Crk_Fact_Pk must read YES (only reads YES if the vehicle transmission is in PARK (P) and Crk_Fact_Neu is NO)

- PCM_ID must read Stored

- N_KEYCODE must read a minimum of 2 (can read 3 or 4)

- MASTERKEY reads Not Present with the ignition OFF and Present with the ignition ON

- PCM_VFY must read Yes

- PATSENABL must read Enabled

Field-Effect Transistor (FET) Protection

Field-Effect Transistor (FET) is a type of transistor that when used with module software can be used to monitor and control current flow on module outputs. The FET (Field-Effect Transistor) protection strategy is used to prevent module damage in the event of excessive current flow.

The RFA (Remote Function Actuator) module utilizes a FET (Field-Effect Transistor) protective circuit strategy for many of its outputs (for example, a headlamp output circuit). Output loads (current level) are monitored for excessive current (typically short circuits) and are shut down (turns off the voltage or ground provided by the module) when a fault event is detected. A continuous DTC is stored at the fault event and a cumulative counter is started.

When the demand for the output is no longer present, the module resets the FET (Field-Effect Transistor) circuit protection to allow the circuit to function. The next time the driver requests a circuit to activate that has been shut down by a previous short (FET (Field-Effect Transistor) protection) and the circuit remains shorted, the FET (Field-Effect Transistor) protection shuts off the circuit again and the cumulative counter advances.

When the excessive circuit load occurs often enough, the module shuts down the output until a repair procedure is carried out. Each FET (Field-Effect Transistor) protected circuit has 3 predefined levels of short circuit tolerance based on the harmful effect of each circuit fault on the FET (Field-Effect Transistor) and the ability of the FET (Field-Effect Transistor) to withstand it. A module lifetime level of fault events is established based upon the durability of the FET (Field-Effect Transistor). If the total tolerance level is determined to be 600 fault events, the 3 predefined levels would be 200, 400 and 600 fault events.

When each tolerance level is reached, the continuous DTC that was stored on the first failure cannot be cleared by a command to clear the continuous DTCs. The module does not allow this code to be cleared or the circuit restored to normal operation until a successful self-test proves that the fault has been repaired. After the self-test has successfully completed (no on-demand DTCs present), DTC U1000:00 and the associated continuous DTC (the DTC related to the shorted circuit) automatically clears and the circuit function returns.

When the first or second level is reached, the continuous DTC (associated with the short circuit) sets along with DTC U1000:00. These DTCs can be cleared using the module on-demand self-test, then the Clear DTC operation on the scan tool (if the on-demand test shows the fault corrected). The module never resets the fault event counter to zero and continues to advance the fault event counter as short circuit fault events occur.

If the number of short circuit fault events reach the third level, then DTC U3000:49 sets along with the associated continuous DTC. This DTC cannot be cleared and the module must be replaced.

The only RFA (Remote Function Actuator) module FET (Field-Effect Transistor) protected output circuit for PATS (Passive Anti-Theft System) are the backup transceiver voltage circuit and the start/stop switch run LED voltage circuit.