Component Description
Anti-Theft Inhibit Switch - Liftgate
The liftgate anti-theft inhibit switch is a single pole switch that is normally open, interrupting the voltage signal sent to it. When the liftgate key cylinder is rotated to open the liftgate, the switch closes, routing the signal to ground. This is interpreted as authorized access to the liftgate compartment using a correctly cut key.
The BCM sends a voltage signal to the liftgate anti-theft inhibit switch. Based on the inputs from the liftgate anti-theft inhibit switch and the liftgate ajar switch, the BCM determines whether or not authorized access to the liftgate compartment occurs.
Door Ajar Switch
The door ajar switches each receive a 12-volt signal from the BCM 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 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 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 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 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 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 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.
Integrated Keyhead Transmitter (IKT)
The IKT incorporates both the PATS functions and the RKE transmitter functions in a single device.
During key programming procedures, the PATS and RKE transmitter of an IKT are both programmed into the BCM.
Passive Anti-Theft System (PATS) Transceiver
The PATS transceiver reads any key that is placed in the ignition. When the ignition is turned to the RUN or START position, the BCM activates the PATS 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.
Liftgate-Trunk Module (LTM)
The LTM controls the operation of the power liftgate. The LTM also determines the liftgate position and sends a liftgate ajar status to the BCM.
Tire Pressure Monitor (TPM) Module
The TPM module is a receiving antenna that receives the wireless signals from RKE transmitters and the TPMS sensors. It communicates the RKE and TPMS data to the BCM over the MS-CAN.
Body Control Module (BCM)
The BCM controls the operation of the perimeter alarm. The BCM receives direct input from all the ajar switches, the hood switch, keyless entry keypad, the door lock control switches, and the PATS transceiver. It receives messages from the TPM module over the MS-CAN for the RKE feature.
If the perimeter alarm is armed and the BCM receives an input indicating an unauthorized entry into the vehicle, or the ignition is turned to the RUN position without a programmed PATS key, the BCM 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.