Principles of Operation

Locks, Latches and Entry Systems







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.

Remote Keyless Entry (RKE)

The SJB receives input from the programmed Remote Keyless Entry (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

Keyless Entry Keypad

The keyless entry keypad provides a method for the customer to access the vehicle without a key or 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 buttons 7/8 and 9/0 being allowed to lock the vehicle.