Siemens Bsm B3 Schematic Verified ((better)) Guide

The Siemens BSM B3 refers to an engine compartment fuse and relay box (Boîtier de Servitude Moteur) commonly used in PSA Group vehicles (Peugeot and Citroën). Finding a "verified" schematic usually involves confirming the specific relay and fuse layouts to troubleshoot common issues like fuel pump failures or lighting malfunctions.  Key Components of the Siemens BSM B3 

Auxiliary Pins (Edge Connector - Left to Right)

| Pin # | Verified Function | Internal Connection | | :--- | :--- | :--- | | 1 | Vcc - High side supply (bootstrap) | Isolated for phase U high-side gate driver | | 2 | Hin_U | High-side gate input (Phase U) – 15V logic | | 3 | Vss_U | High-side return (Phase U) | | 4 | NTC+ | Positive lead of NTC thermistor (100kΩ @ 25°C) | | 5 | NTC- | Negative lead of NTC | | 6 | Lin_U | Low-side gate input (Phase U) | | 7 | Vss | Common low-side return | | 8 | Vcc_L | Low-side supply voltage (typically +15V) | | 9 | Hin_V | High-side gate input (Phase V) | | 10 | Vss_V | High-side return (Phase V) | | 11 | Lin_V | Low-side gate input (Phase V) | | 12 | Hin_W | High-side gate input (Phase W) | | 13 | Vss_W | High-side return (Phase W) | | 14 | Lin_W | Low-side gate input (Phase W) | | 15 | Fault | Open-collector fault output (active low) | siemens bsm b3 schematic verified

Internal Connections: Verified diagrams detail how the engine system interface block coordinates power to various components via the internal electronic board. Vehicle Compatibility The Siemens BSM B3 refers to an engine

Step 3: The NTC Thermistor

Measure between Pin 4 and Pin 5. At room temperature (25°C), you should see 98kΩ to 102kΩ. As you heat the module with a hairdryer, the resistance should drop smoothly. No change = broken or incorrect pinout. Vehicle Compatibility Step 3: The NTC Thermistor Measure

, which manages power distribution to fuel pumps, ignition, and lighting via a series of integrated relays and fuses. Key Schematic & Wiring Details