Principles of Operation (How Does It Work?) Module Controlled

The remote keyless entry system is controlled by the Generic Electronic Module (GEM). The switches are wired directly to the lock/unlock relays and the GEM is wired to the relays in parallel. Pressing a switch to lock or unlock grounds the appropriate lock/unlock coil closing the relay and supplying voltage to the actuator to lock/unlock the doors.

Entering the keypad button sends a ground signal to the GEM. When the code is entered in the correct order the GEM grounds the driver unlock relay coil closing the relay and supplying voltage to the driver door actuator unlocking the driver door only. Pressing 3/4 within 5 seconds of factory code sends another ground signal to the GEM causing the GEM to ground the all door unlock relay coil supplying voltage to the passenger door lock actuators unlocking the passenger doors. Pressing 7/8 9/0 buttons together at any time sends a ground signal to the GEM causing the GEM to ground the all door lock relay coil supplying voltage to all the door lock actuators causing them to lock.

The transmitter sends a signal to the GEM causing the GEM to unlock the driver or passenger doors depending on the button pressed.

When the GEM receives the correct signal from either the keyless entry keypad or the remote transmitter the GEM will then command the interior courtesy lamps and the keypad illumination on.

When the panic function is activated from the remote transmitter, the GEM intermittently grounds the parklamp Hash relay and the horn relay coils closing the relays and supplying voltage to both the parking lamps and the horn.

The remote transmitters and the remote key less entry use a rolling code to prevent the Transmitter Identification Code (TIC) code from being captured" by a code grabber. The system rolls the counter in the transmitter and in the remote key less entry every time a remote transmitter button is pressed. If the remote transmitter is pressed a large number of times outside the range of the vehicle, the rolling codes will fail to synchronize and the vehicle will stop responding to that remote transmitter. At this point the transmitter needs to be reprogrammed to the system.