Anti-Theft - With Intelligent Access (IA)
Anti-Theft - With Intelligent Access (IA)
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.
NOTE: When using the Integrated Diagnostic System (IDS), the RFA (Remote Function Actuator) module and the PCM parameters are reset at the same time.
NOTE: Make sure any aftermarket remote start systems have been removed from the vehicle before any Passive Anti-Theft System (PATS) -related no-start concerns are investigated.
NOTE: A minimum of 2 IA (Intelligent Access) keys must be programmed into the RFA (Remote Function Actuator) module before the vehicle can start.
NOTE: If the RFA (Remote Function Actuator) module or the PCM is being replaced (or both), 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 - With Intelligent Access (IA) .
NOTE: The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).
Anti-Theft Indicator
PATS (Passive Anti-Theft System) flashes the anti-theft indicator every 2 seconds when the ignition is in the OFF mode to act as a visual theft deterrent. Refer to Instrument Panel, Gauges and Warning Indicators for information on the anti-theft indicator.
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.
Intelligent Access (IA)
NOTE: A maximum of 4 IA (Intelligent Access) keys can be programmed into the RFA (Remote Function Actuator) module.
NOTE: The IA (Intelligent Access) key must be inside of the vehicle in order to be used for starting the vehicle. There are a few areas within the vehicle that are out of reach of the 3 interior vehicle passive start antennas and can precipitate 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 package tray
- 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.
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.
NOTE: If the battery in the IA (Intelligent Access) key becomes inoperative, place the IA (Intelligent Access) key in the backup transceiver slot to start the vehicle. If the vehicle starts, that indicates the IA (Intelligent Access) key is programmed, the backup transceiver, its circuitry to the RFA (Remote Function Actuator) module, the RFA (Remote Function Actuator) module, the start/stop switch and its circuitry to the RFA (Remote Function Actuator) module, the PCM and all of the driveability components are OK. If the vehicle starts with the IA (Intelligent Access) key in the backup slot, but cannot start with the IA (Intelligent Access) key anywhere else in the vehicle interior, 1, 2 or all of the passive start antennas, the RFR (Remote Functions Receiver) module, the RFA (Remote Function Actuator) module, the circuitry between the passive start antennas and the RFR (Remote Functions Receiver) module, or the circuitry between the RFR (Remote Functions Receiver) module, the RFA (Remote Function Actuator) module may be at fault and the IA (Intelligent Access) key battery may also be at fault. There may also be an RF interference issue in the area that is causing the problem. If the behavior is intermittent, it is likely an interference issue.
PATS (Passive Anti-Theft System) uses a special ignition key, called an IA (Intelligent Access) key that is larger than a conventional ignition key and looks more like a large Remote Keyless Entry (RKE) transmitter. It contains a permanently-installed electronic device called a transponder and has the RKE (Remote Keyless Entry) transmitter integrated into it. Each transponder contains a unique encrypted identification code which is one of a very large number of combinations. The IA (Intelligent Access) key has a battery that should last the lifetime of the vehicle. Each IA (Intelligent Access) key must be programmed into the RFA (Remote Function Actuator) module before it can be used to start the vehicle. A maximum of 4 IA (Intelligent Access) keys can be programmed to start the vehicle and operate the RKE (Remote Keyless Entry) functions. If more than 4 IA (Intelligent Access) keys are attempted to be programmed, the message center in the IPC (Instrument Panel Cluster) displays KEY PROGRAMMED, 4 KEYS TOTAL, then displays MAX # OF KEYS PROGRAMMED. There are special procedures described that must be carried out if a new IA (Intelligent Access) key is necessary. Refer to Key Programming Using Diagnostic Equipment - With Intelligent Access (IA) or Key Programming Using Two Programmed Keys - With Intelligent Access (IA) .
Passive Start Antennas
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 on the floorpan, under the rear seat cushion. These 3 passive start antennas all receive a voltage (wake-up) signal from the RFA (Remote Function Actuator) module when the start/stop button is pressed or when the brake pedal is pressed. Whenever a front door is opened and closed, this also causes a voltage signal to be sent to all of the passive start antennas. They send out a low frequency query in an effort to identify if any IA (Intelligent Access) keys are within range of one of them. If an IA (Intelligent Access) key is within range (approximately 1 m [3 ft]), the IA (Intelligent Access) key sends a high frequency signal to the RFR (Remote Functions Receiver) module, which sends the key identification code to the RFA (Remote Function Actuator) module over a hardwired circuit between the RFR (Remote Functions Receiver) module and the RFA (Remote Function Actuator) module.
Backup Transceiver
The backup transceiver is located in the left rear of the floor console and its associated backup transceiver slot is located in the left rear corner of the floor console storage compartment. Make sure the transmitter buttons are facing forward and the key ring is up for the most efficient backup transceiver operation.
The backup transceiver can be used if the IA (Intelligent Access) key battery fails or if the customer desires to keep the IA (Intelligent Access) key out of sight. If the IA (Intelligent Access) key battery fails, the passive start antennas cannot receive the IA (Intelligent Access) key identification code and the vehicle experiences a PATS (Passive Anti-Theft System) no-start. If the IA (Intelligent Access) key is placed in the backup transceiver slot, the backup transceiver can read the key identification code and send it to the RFA (Remote Function Actuator) module so the vehicle can be started. If the IA (Intelligent Access) key is placed in the backup transceiver slot, the backup transceiver reads the IA (Intelligent Access) key identification code and sends the data directly to the RFA (Remote Function Actuator) module over hardwired circuits.
It is not recommended to leave the IA (Intelligent Access) key in the backup transceiver slot as this decreases the security of the vehicle.
Whether the IA (Intelligent Access) key identification code is read by the backup transceiver or by one of the passive start antennas, the RFA (Remote Function Actuator) module validates the code, and if it is correct, sends a message to the PCM (OK-to-start) to ground the run/start relay solenoid coil and allow the fuel injectors to operate.
Passive Anti-Theft System (PATS) Operation
NOTE: The start/stop switch and the start/stop button verbiage may be used in place of each other to avoid confusion about the 2 separate functions each provide. Essentially, they are the same component and cannot be obtained separately.
The PATS (Passive Anti-Theft System) function is controlled by the RFA (Remote Function Actuator) module. With this type of PATS (Passive Anti-Theft System) there are parameters that need to be reset if either the RFA (Remote Function Actuator) module or the PCM (or both) are replaced. Refer to Passive Anti-Theft System (PATS) Parameter Reset - With Intelligent Access (IA) .
When the start/stop button and/or the brake pedal is pressed, the RFA (Remote Function Actuator) module initiates the key interrogation sequence by sending a voltage (wake-up) signal to the 3 interior IA (Intelligent Access) passive start antennas. The 3 passive start antennas send out a low frequency query to see if an IA (Intelligent Access) key is within range (approximately a 1 m [3 ft] radius of each antenna). If an IA (Intelligent Access) key is within range of 1 of the 3 passive start antennas, this process "reads" the PATS (Passive Anti-Theft System) IA (Intelligent Access) key identification code and sends the key identification code back to the RFA (Remote Function Actuator) module, which interprets it and determines if it matches one of the stored keycodes.
If no IA (Intelligent Access) key responds to the request from the 3 passive start antennas, the RFA (Remote Function Actuator) module initiates communication with the backup transceiver. The transceiver then uses its antenna to bounce a signal off the transponder in the IA (Intelligent Access) key (only if the IA (Intelligent Access) key is in the backup slot). The backup transceiver also sends out a low frequency signal, but it only travels 77 mm (3.031 in).
If the IA (Intelligent Access) key is in the backup slot, the key identification code is sent to the RFA (Remote Function Actuator) module using the hardwired circuits between the backup transceiver and the RFA (Remote Function Actuator) module. If the IA (Intelligent Access) key is within range of 1 of the 3 passive start antennas, the antenna that is within range of the IA (Intelligent Access) key sends a high frequency message to the RFR (Remote Functions Receiver) module. The RFR (Remote Functions Receiver) module sends the key identification code over a hardwired circuit to the RFA (Remote Function Actuator) module. If it does match one of the stored keycodes, the RFA (Remote Function Actuator) module turns on the run/start relay and sends a message to the PCM to ground the starter relay solenoid coil and allow the fuel injectors to operate. If it does not match one of the stored keycodes, or it is only a partial key read or no key read, the RFA (Remote Function Actuator) module does not activate the run/start or run/accessory relays and the PCM never receives ignition run power.
All elements of PATS (Passive Anti-Theft System) must be functional before the vehicle starts. If any of the components are not working correctly, the vehicle cannot start.
If the RFA (Remote Function Actuator) module must be replaced for any reason (PATS (Passive Anti-Theft System) issues or RFA (Remote Function Actuator) module issues), the PATS (Passive Anti-Theft System) IA (Intelligent Access) keys must also be programmed into the new RFA (Remote Function Actuator) module. Refer to Key Programming Using Two Programmed Keys - With Intelligent Access (IA) .
If the RFA (Remote Function Actuator) module is replaced, the keyless entry keypad code in the SJB (Smart Junction Box) must be programmed into the new RFA (Remote Function Actuator) module. Programmable Module Installation (PMI) does not resolve this. Refer to Keyless Entry Keypad Code Programming in Doors, Hood and Trunk &/or Locks.
A PATS (Passive Anti-Theft System) no-start may involve a vehicle no-start due to either the fuel injectors not operating or the starter not operating (or both). A low battery voltage condition may cause the PATS (Passive Anti-Theft System) to allow starter operation, but may keep the fuel injectors from operating.
PATS (Passive Anti-Theft System) is not compatible with aftermarket remote start systems, which allow the vehicle to be started from the exterior of the vehicle. These systems can reduce the security of the vehicle, and can also cause no-start concerns. Remote start systems must be removed from the vehicle before any PATS (Passive Anti-Theft System) -related no-start concerns are investigated.
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 (PCM_ID PID) from the RFA (Remote Function Actuator) module. A PCM parameter reset causes the PCM to send a PCM ID 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 turn the ignition to ON, 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 IDS (Integrated Diagnostic System) 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 - With 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 - With Intelligent Access (IA) .
Cranking Factor PIDs
The Crk_Fact_B1 PID (Cranking Factor B1, Start/Stop button circuit 1) and the Crk_Fact_B2 PID (Cranking Factor B2, Start/Stop button circuit 2) must read YES, but it is only necessary for one of them to read YES as they are redundant circuits. If one of the start/stop button circuits fail, DTC B108A:15 (Start Button: Circuit Short To Battery Or Open) can set and if cleared, may not reappear. The start/stop button still operates using the backup circuit, but if the second circuit should also fail, the start/stop button cannot operate.
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 - With 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 - With 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.
NOTE: The Crk_Fact_Neu and the Crk_Fact_Pk PIDs cannot both read YES. It is only necessary for one of them to read YES for the vehicle to start.
In summary, for the PATS (Passive Anti-Theft System) PIDs and their correct state in order for the vehicle to start:
- 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). If the values do not match, and if the circuitry is OK, the start/stop switch should be replaced
- 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
Preliminary Checklist For A Passive Anti-Theft System (PATS) No-Start Vehicle
NOTE: If the IA (Intelligent Access) key(s) can be read by the RFA (Remote Function Actuator) module, the ignition mode changes to ON. In this case, there can be a parameter reset concern or the HS-CAN (High Speed Controller Area Network) circuitry can be down. If the IA (Intelligent Access) keys cannot be read by the RFA (Remote Function Actuator) module, the ignition does not turn on. In this case, there can be an unprogrammed, or damaged IA (Intelligent Access) key, a damaged passive start antenna, a damaged RFR (Remote Functions Receiver) module, a damaged RFA (Remote Function Actuator) module or damaged circuitry.
Preliminary Checklist
Message Center Diagnostic Information
