BCM Function
WARNING: This page is about a different car, the 2005 Infiniti FX45 and 2005 Infiniti FX35. However, it is still accessible from the selected car via links, so may be relevant.
BCM has combination switch reading function for reading the operation of combination switches (light, wiper, washer and turn signal) in addition to a function for controlling the operation of various electrical components. Also it has an interface function allowing it to receive signals from the unified meter and A/C amp., and send signals to ECM using CAN communication.