Principles of Operation

PRINCIPLES OF OPERATION

NOTE: The smart junction box (SJB) is also known as the generic electronic module (GEM).

Power Locks
The SJB monitors the door lock control switches.When the SJB receives an unlock/lock command from either door lock control switch, the SJB energizes a relay (internal to the SJB) to supply the correct power and grounds for the door lock actuators.

Keyless Entry Keypad
The keyless entry keypad provides a method for the customer to access the vehicle without a key or remote keyless entry (RKE) transmitter. The keyless entry keypad feature:
- locks all the doors.
- unlocks the driver door.
- unlocks all the doors.
- programs/erases a personal entry code.
- enables/disables the autolock feature.
- enables/disables the auto-unlock feature.

When a keyless entry keypad button is pressed, the keypad buttons illuminate to provide better visibility. If the 7/8 and 9/0 buttons are pressed, or 5 seconds have elapsed since the last button press, the illumination turns off.

Vehicles equipped with a keyless entry keypad are programmed with a factory set 5-digit entry code. This code is provided to the customer on a wallet card in the Owner Literature package. In addition, this code is available through the use of a scan tool, and is printed on the SJB label located on the back side of the module (installed position). When entering codes, each digit must be entered within 5 seconds of the previous button press.

Anti-Scan Feature
To provide added security, the keyless entry keypad is disabled for 1 minute after pressing the keypad buttons 35 times without a valid entry code being entered. The keypad illumination flashes during this 1-minute mode. All functionality is disabled except for 7/8 and 9/0 being allowed to lock the vehicle.

Remote Keyless Entry (RKE)
The SJB receives input from programmed RKE transmitters. Based on input from the RKE transmitter, the SJB:
- Locks all doors
- Unlocks the driver door
- Unlocks all doors
- Activates/deactivates the panic alarm
- Turns the interior lamps on (when unlocking) and off (when locking), provided the defeat switch on the dimmer switch is not active
- Sounds the horn once when LOCK is pressed twice within 3 seconds, and the doors are closed
- Sounds the horn twice when LOCK is pressed twice within 3 seconds, and any door is open