Component Description

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.

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.

The BCM sends the door lock control switch command over the MS-CAN to the RFA module. The RFA module then locks or unlocks the doors depending upon the switch input.

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 RFA 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. Based upon input from the keyless entry keypad, the RFA module either locks or unlocks the doors.

Intelligent Access (IA) Key 

The Intelligent Access (IA) key incorporates both the PATS and the RKE transmitter functions in a single device. The Intelligent Access (IA) key must be located inside the vehicle for engine starting and on the outside for Intelligent Access (IA) features. During key programming procedures, the PATS and RKE transmitter of an Intelligent Access (IA) key are both programmed into the RFA module. The RFA module accepts programming of up to 4 Intelligent Access (IA) keys.

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, and the door lock control switches. It receives messages from the RFA module over the MS-CAN for the lock/unlock status of the vehicle.

If the perimeter alarm is armed and the BCM receives an input indicating an unauthorized entry into the vehicle, 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.

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 the Intelligent Access (IA) keys and the TPMS sensors. It communicates the TPMS data to the BCM over the MS-CAN. The Intelligent Access (IA) key data is sent to the RFA module through a dedicated single circuit network.

Remote Function Actuator (RFA) Module 

The RFA module controls the locking and unlocking of the vehicle. The RFA module receives direct input from the keyless entry keypad, it also receives input from the TPM module over a dedicated single wire network for the RKE and Intelligent Access (IA) features.

The RFA module sends the lock/unlock status of the vehicle over the MS-CAN to the BCM. The BCM uses this information to determine the status of the perimeter alarm.