Theory Of Operation
WARNING: This page is about a different car, the 2013 RAM 1500. However, it is still accessible from the selected car via links, so may be relevant.
The Body Control Module (BCM) is the Local Interconnect Network (LIN) master for the Light Rain Sensing Module (LRSM). The LRSM performs an internal self test and sends the information to the BCM. The repair of this fault condition does not involve any external circuitry and centers on verifying the integrity of the internal circuitry and software validity.