door lockING (Early 95) - quick reference
Before mid-1995, locking and unlocking the doors was done using the physical key. Inside the lock cylinder, a switch briefly grounds either the 'prime' or 'unprime' input of the Alarm Control Unit (ACU), based on the direction the key is turned. The ACU then activates the lock actuators and either arms or disarms the system. Limit switches within the actuators provide feedback to verify the position of the locks. More detail
door locking (Early 95) - Detailed
Scroll down for late 95- 98
door locking (Late 95 - 98) - quick reference
In mid-1995, Porsche introduced the Drive Block System, offering enhanced security and remote door lock/unlock functionality. Instead of using cylinder lock switches like in earlier models, the new system relies on the immobilizer module, which responds to signals from a radio frequency key FOB. Each time the FOB is pressed, the immobilizer sends a lock or unlock pulse directly to the ACU. The ACU then operates the lock actuators and arms or disarms the alarm, just as it did in early 1995 models. More detail.
door locking (Late 95 - 98) - detailed
