Finding the right pinout for these legacy servo motors can be tricky. If you are integrating with a new drive or troubleshooting a fault, make sure to cross-reference the nameplate code on the Siemens Support Portal.
: Manages high-current circuits with built-in fuses. It supports a wide voltage range (24V to 690V depending on specific fuse application) and high breaking capacity up to 120kA for short-circuit protection. Diagnostic Interface siemens bsm b3 schematic
The module is identified by colored connectors (Black, Grey, Green) that interface with the engine loom and the interior BSI (Built-in Systems Interface). Key Pins / Functionality Black (28-pin) Main engine management, sensors, and actuator power. Grey (16-pin) Headlight controls, horn, and wiper power. Green (2-pin) High-current power supply from the battery. Key terminal paths include: Finding the right pinout for these legacy servo
If you have the motor nameplate, head to the Siemens Industry Online Support site. You are generally looking for documentation in the catalog, often under manual code D 21.1 or similar. It supports a wide voltage range (24V to
Moisture infiltration, electrical surges, or relay burnout (e.g., fuel pump relay) Repair & Modification Tips Internal Access