Siemens: Bsm B3 Schematic

Data wire channels interacting with the cabin BSI.

The tier level (B2, B3, B4, B5) dictates factory-installed internal relays. A BSM B3 unit features integrated relays for front fog lights (which B2 units often lack) but excludes specific auxiliary relays found in B4 and B5 tiers (such as secondary air injection pumps). siemens bsm b3 schematic

Hidden at the bottom or sides of the unit, these supply high-current systems like the radiator fan, ABS block, and cabin climate blowers. Data wire channels interacting with the cabin BSI

This connector handles the digital multiplex communication and low-power trigger signals returning to the dashboard. siemens bsm b3 schematic

Control triggers for headlights, horn, and wiper low/high speeds. BSM | PDF - Scribd