OSM System Addressing: Notes
Each OSM is equipped with address pins connected through the vehicle's wiring harness. These address pins allow the BCM to determine which OSM it is monitoring as it scans the lighting system. The address is determined by pins "C", "D", "E" and "F". Each OSM will have these 4 pins connected in a combination that is unique to the lighting function the OSM is located at.
Each of the 4 pins on the OSM has a different value. The total value of the pins used for each OSM constitutes its address. Pins not used by the OSM have a plastic plug inserted in the unused pin cavity. The OSM values are 8 for pin "C", 4 for pin "D", 2 for pin "E" and 1 for pin "F".
An example would be an OSM with plastic plugs at pin cavities "C" and "F" (Pin "C" being a value of 8 and pin "F" being a value of 1). This leaves pin cavities "D" and "E" for address wires to be connected. Since pin "D" has a value of 4 and pin "E" has a value of 2, the OSM Would have a value of 6. The BCM will read this address as OSM Module No. 6. See Fig 1.