Description & Operation: Communication
WARNING: This page is about a different car, the 1989 Cadillac Allante. However, it is still accessible from the selected car via links, so may be relevant.
The communication between the nine OSMs, the BCM, and the Left Switch Pod is achieved via the lighting data line. The BCM will continuously scan from the Left Switch Pod to each of the nine OSMs one at a time, making commands to each, and requesting information from each. The data line is designed as a complete loop so that each element on the data circuit has two data circuit inputs. This loop design will allow the circuit to operate with one open in the circuit. For details on the data circuit, see Fig 1 .