4. Central locking system
WARNING: This page is about a different car, the 2005 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.
BCM contains all logic for the central locking system. When the unlocking button on the remote control is pressed, CIM receives the radio signal. CIM then activates the other I-bus control modules and transmits which button was pressed and how it was pressed (e.g. single press). BCM transmits the unlock command on the bus, at which time the four door modules (DDM, PDM, RRDM, and RLDM) unlock their respective door. The Rear Electronic Module (REM) unlocks the boot lid/tailgate and BCM unlocks the fuel filler flap.
4D
CV
The BCM contains the central locking logic and can be programmed to unlock only the driver's door and fuel filler flap if the unlock button is only pressed once.