Keyless Entry: Description and Operation
Immobilizer / Central Locking
Ignition Lock with Single-key System
The Cayenne is equipped with a central locking system, which along with an engine immobilizer, provides the highest level of theft deterrence. Standard equipments includes a remote control integrated into the key which, using two buttons, locks and unlocks all doors and opens the rear window or gate. In addition. the glove box, the sunroof and gas tank lid are included in the central locking system.
In the North American market, the remote control also has a "panic button." In an emergency, pushing the "panic button" turns on the exterior lighting in blinking mode and activates the horn at the same time.
The rear control module controls the logic for the central locking system functions. Depending upon status information (e.g., key status) the rear control module generates functions and central locking commands for the door control module). System codes affect only the rear control module. Communication is via the CAN convenience bus.
Functional components:
- Operating controls, doors
- Door control modules
- Rear control module
Central Locking Controls:
- Remote control (standard)
- Lock-unlock button in all doors
- Key cylinder driver's door Keyless entry (I-option)
The central locking system has two locking levels.
Pressing the Cayenne's key remote once activates "Secure" locking, ideal for most situations. The doors can only be opened with the remote control and not by using the interior door handles.
This prevents access to the vehicle by operating the interior door handles through an open sunroof.
Pressing the remote control twice in rapid succession prevents the Cayenne from being accessed from the outside. The doors can be opened from within. This mode is appropriate if passengers wish to remain in the vehicle.
Alternate Operation
In the event of remote control failure, locking and unlocking is performed using the locking cylinder in the driver's door. If the door control module cannot receive rear control module CAN signals, an alternate function is used.
- Every door module stores the missing bus user in a separate error code memory.
- The driver's door module takes over the master function for the electrical central locking system. The other door modules respond to the central locking status message from the driver's door module.
- Specifically the two states, "unlock" and "lock," of the driver's door locking cylinder and the switching information of the Lock/Unlock buttons are command signals to be received and evaluated by the other door control modules. The controls of the other doors are locked out.
The standard immobilizer uses a transponder system like that used by the sports cars. When the ignition is switched on, the data code in the transponder in the head of the key is compared to that of the vehicle electronics. Upon correct identification, the immobilizer is disabled and the engine may start, Arming and disarming the immobilizer is a background task. In addition, removing the key from the ignition lock activates a steering column lock operated by an electromagnetic locking ring.
If an original key is lost, the replacement can be "taught" the code using the Porsche System Tester 2. Lost keys can be deactivated. In this way only authorized persons can have access to properly coded keys.