Circuit Operation: Unlock
The Unlock function is separated into 2 operations depending on how the Unlock button is pressed on the transmitter. If the Unlock button is pressed once, only the left front door is unlocked. If the Unlock button is pressed twice within 1 1/2 seconds, all doors will be unlocked. In both cases, the illuminated entry function is activated (if there is low ambient light).
When the Unlock button is pressed once on the transmitter, and the keyless entry module receives a signal with a valid VAC, the unlock function sequence is performed. The keyless entry module will simultaneously start the following 2 operations:
- The keyless entry module will activate the illuminated entry output at pin C7 which simulates a door handle being lifted. See WIRING DIAGRAMS . The output signal is a 5 pulse signal, which is detected by the Body Control Module (BCM) at pin 1C13. The BCM will then provide a ground for the courtesy lights at pin 1C1 (if there is low ambient light), and the courtesy lights come on.
- The keyless entry module will activate its left door unlock output at pin C16. Voltage will be supplied to the left door lock motor. The motor is grounded through the contacts of the Lock relay in the Door Lock relay. The left front door lock motor runs unlock just the driver's door.
If the Unlock button on the transmitter is pressed twice to unlock all doors, the keyless entry module will perform the same 2 unlock operations listed above. It will also activate the door unlock output at pin C2. See WIRING DIAGRAMS . The keyless entry module will then supply battery voltage to the coil of the Unlock relay in the Door Lock Relay. The Unlock relay is energized and closes its contacts. Battery voltage is supplied to the right door lock motor. The motor is grounded through the contacts of the Lock relay in the Door Lock Relay. The motor runs to unlock the passenger's door.
If the ignition switch is ON, only the left front door will unlock. All doors are unlocked automatically if the vehicle key is turned to unlock twice in the left door lock cylinder or right door lock cylinder. The door lock cylinder input (pin C8) is grounded through the door lock cylinder switch. This input will enable the door unlock output (pin C2) as well as the left front unlock output (pin C16) to be activated. All doors will unlock.