Anti-Theft - Perimeter-without Intelligent Access (IA)
Anti-Theft - Perimeter-without Intelligent Access (IA)
Overview
The perimeter alarm system protects the vehicle from unauthorized entry by sounding the horn and flashing both the turn signals and courtesy lights when an unauthorized entry occurs. The horn and lights are active for 30 seconds. After 30 seconds, the horn stops sounding, but the lights continue to flash for up to 5 minutes.
The panic alarm operates similar to the perimeter alarm, but is only controlled by the panic button on a RKE (Remote Keyless Entry) transmitter. REFER to Remote Keyless Entry (RKE) Handles, Locks, Latches and Entry Systems - without Intelligent Access (IA) for information on the panic alarm operation.
System Operation
System Diagram
Network Message Chart
Module Network Input Messages - BCM (Body Control Module)
Module Network Input Messages - IPC (Instrument Panel Cluster)
Anti-Theft - Perimeter
Arming the Perimeter Alarm
The perimeter alarm is ready to arm any time the ignition is off. Any of the following pre-arms the alarm system:
- pressing the lock button on a RKE (Remote Keyless Entry) transmitter.
- pressing the door lock control switch to the lock position with the door open, then closing the door.
- touching the 7/8 and 9/0 buttons simultaneously on the keyless entry keypad.
Once the system is pre-armed, there is a 20-second countdown before the perimeter alarm is armed. Each entry point to the vehicle (hood, door, or liftgate) is armed separately and must be closed before that entry point begins the 20-second countdown to become armed. If all entry points are closed, the turn signals flash indicating that all entry points are entering the 20-second countdown.
Perimeter Alarm Activation
The perimeter alarm has a 12-second delay when the driver door is unlocked and opened using a key in the door lock cylinder. During the delay, a chime sounds and TO STOP ALARM START VEHICLE is displayed in the message center. If the perimeter alarm is not disarmed within the 12-second delay, the alarm is activated.
The perimeter alarm is activated when:
- any passenger door, liftgate, or the hood is opened without first receiving an electronic unlock command from a RKE (Remote Keyless Entry) transmitter or keyless entry keypad.
- the driver door is opened without first receiving an unlock command from a RKE (Remote Keyless Entry) transmitter or keyless entry keypad and the 12-second delay has expired.
- the ignition is transitioned to RUN without a valid PATS (Passive Anti-Theft System) key read received.
The perimeter alarm only activates 10 times per arming cycle. After that the alarm does not activate. To enable the perimeter alarm again, disarm the perimeter alarm and then arm it again.
Disarming the Perimeter Alarm
The perimeter alarm can be disarmed by:
- pressing the unlock button on a programmed RKE (Remote Keyless Entry) transmitter.
- pressing the liftgate release button on a programmed RKE (Remote Keyless Entry) transmitter.
- using a programmed key to transition the ignition to the RUN mode.
- entering the correct vehicle unlock code on the keyless entry keypad.
The perimeter alarm can be deactivated by pressing the panic button on a RKE (Remote Keyless Entry) transmitter. All of the lamps stop flashing and the horn stops sounding, but the alarm is still armed.
Component Description
Hood Switch
The hood switch receives a voltage signal from the BCM (Body Control Module) on an input circuit. When the hood is closed, the hood switch is closed, routing the signal to ground. When the hood is opened, the hood switch opens, interrupting the signal. The BCM (Body Control Module) interprets this as an open hood.
Door Ajar Switch
The door ajar switches each receive a 12-volt signal from the BCM (Body Control Module) on independent circuits. When the door is closed, the door ajar switch is closed, routing the signal to ground. When the door is opened, the door ajar switch opens, interrupting the signal. The BCM (Body Control Module) interprets this as an open door.
The door ajar switches are part of the door latches and not serviceable separately.
Liftgate Ajar Switch
The liftgate ajar switch receives a 12-volt signal from the BCM (Body Control Module) on an independent circuit. When the liftgate is closed, the liftgate ajar switch is closed, routing the signal to ground. When the liftgate is opened, the liftgate ajar switch opens, interrupting the signal. The BCM (Body Control Module) interprets this as an open liftgate.
The liftgate ajar switch is part of the liftgate latch and not serviceable separately.
Door Lock Control Switch
The door lock control switches receive voltage signals from the BCM (Body Control Module) on the lock and unlock input circuits. When the switch is pressed to lock or unlock, the corresponding input circuit is routed to ground, signalling the BCM (Body Control Module) to lock or unlock the doors. The door lock control switches have a dedicated ground circuit.
Keyless Entry Keypad
The keyless entry keypad is a touch sensitive capacitive sensor. When a finger touches the keypad, it changes the capacitance of the sensor in the area of the finger touch. The keypad is then able to determine which area was touched and sends a ground signal to the BCM (Body Control Module) on the corresponding reference circuit(s). The keypad only works when touched with a finger. The keyless entry keypad may not work when gloves are worn. The gloves act as an insulator and do not allow the finger to change the sensor capacitance.
REFER to Keyless Entry Keypad Handles, Locks, Latches and Entry Systems - without Intelligent Access (IA) for information on the operation of the keypad.
Integrated Keyhead Transmitter (IKT)
The IKT (Integrated Keyhead Transmitter) incorporates both the PATS (Passive Anti-Theft System) functions and the RKE (Remote Keyless Entry) transmitter functions in a single device.
During key programming procedures, the PATS (Passive Anti-Theft System) and RKE (Remote Keyless Entry) transmitter of an IKT (Integrated Keyhead Transmitter) are both programmed into the BCM (Body Control Module). 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 to program the IKTs (Integrated Keyhead Transmitters).
Passive Anti-Theft System (PATS) Transceiver
The PATS (Passive Anti-Theft System) transceiver reads any key that is placed in the ignition. When the ignition is turned to the RUN or START position, the BCM (Body Control Module) activates the PATS (Passive Anti-Theft System) transceiver. Once the transceiver is activated, it activates the key in the ignition and receives the key data. Once the transceiver receives the key data, it sends the data to the BCM (Body Control Module).
Liftgate-Trunk Module (LTM)
The LTM (Liftgate/Trunk Module) controls the operation of the power liftgate. The LTM (Liftgate/Trunk Module) also determines the liftgate position and sends a liftgate ajar status to the BCM (Body Control Module). REFER to Liftgate/Trunk Module (LTM) Description and Operation.
Tire Pressure Monitor (TPM) Module
The TPM (Tire Pressure Monitor) module is a receiving antenna that receives the wireless signals from RKE (Remote Keyless Entry) transmitters and the TPMS (Tire Pressure Monitoring System) sensors. It communicates the RKE (Remote Keyless Entry) and TPMS (Tire Pressure Monitoring System) data to the BCM (Body Control Module) over the MS-CAN (Medium Speed Controller Area Network). REFER to Tire Pressure Monitoring (TPM) Module Description and Operation.
Body Control Module (BCM)
The BCM (Body Control Module) controls the operation of the perimeter alarm. The BCM (Body Control Module) receives direct input from all the ajar switches, the hood switch, keyless entry keypad, the door lock control switches, and the PATS (Passive Anti-Theft System) transceiver. It receives messages from the TPM (Tire Pressure Monitor) module over the MS-CAN (Medium Speed Controller Area Network) for the RKE (Remote Keyless Entry) feature.
If the perimeter alarm is armed and the BCM (Body Control Module) receives an input indicating an unauthorized entry into the vehicle, or the ignition is turned to the RUN position without a programmed PATS (Passive Anti-Theft System) key, the BCM (Body Control Module) activates the perimeter alarm. When the perimeter alarm is activated, the horn sounds and both the turn signals and courtesy lights flash in regular intervals. REFER to Body Control Module (BCM) Description and Operation.