Body Domain Controller

KCU BCM

A body domain controller for electric buses and commercial vehicles, integrating front/rear BCM, lighting, doors, HVAC, wipers, ADAS/IVI power, and high-density 24V load control.

KCU BCM product studio photo

Positioning

A body domain controller for electric buses and commercial vehicles, integrating front/rear BCM, lighting, doors, HVAC, wipers, ADAS/IVI power, and high-density 24V load control.

Each KCU-BCM integrates 56 signal inputs, 50 power/actuator outputs, four sensor-supply channels, and multiple in-vehicle networks.

Front and rear BCMs use identical hardware: the front unit aggregates strategy and diagnostics, while the rear unit executes rear-body I/O over CAN FD.

Designed for 9–32 V commercial-vehicle electrical systems, with 2.5 kW output power, 105 A maximum normal current, and per-channel electrical diagnostics and protection.

System Architecture

Think of KCU-BCM as the sensing, decision, and protected power-distribution center for body electronics. It reads switches, sensors, and network commands, evaluates vehicle state, then safely drives doors, lighting, wipers, fans, and other 24 V loads.

BODY SIGNAL AND LOAD CONTROL9–32 V · CAN FD · LIN · Ethernet*
01 | VEHICLE INPUTS

Power, signals, and networks

Receives body switches, sensors, and commands from other ECUs while managing the 9–32 V supply and wake-up sources.

56 inputs: SG 28, SP 16, frequency 4, analog 4, resistive 4
CAN FD ×3, LIN ×1, 100BASE-T1 ×1 (optional)
02 | CONTROL CORE

KCU BCM

The S32K344 executes body strategies, interlocks, diagnostics, and security, then decides when each load may operate.

State machines, safety interlocks, and power sequencing
UDS diagnostics, degraded modes, and Inter-BCM coordination
03 | PROTECTED OUTPUTS

Power drivers and body loads

Current-monitored, fault-protected driver stages operate the front and rear body equipment.

50 outputs: HSD 36, half-bridge 6, LSD 8
Doors, lighting, wipers, HVAC, pumps, and ADAS / IVI power

How do the front and rear BCMs share the work?

Both units use identical hardware and are placed near their local wiring. Strategy stays in the front BCM; the rear BCM executes nearby outputs and returns diagnostics.

Front BCM (functional master)

Runs body strategy, state machines, safety evaluation, diagnostic aggregation, and the UDS gateway, while controlling front lighting, front doors, wipers, horn, EPS, and front ADAS power.

Inter-BCM CAN FD · signal synchronization ≤ 100 ms

Rear BCM (I/O executor)

Controls rear lighting, rear doors, cooling fans, pumps, rear cameras, and cabin electronics, and reports local open-load, short-circuit, over-current, and over-temperature faults.

The Master/Slave architecture separates responsibilities: the front BCM coordinates body strategies and the rear BCM executes local I/O. If communication is interrupted, the rear BCM handles outputs through its defined safety strategy.

Specifications

Signal Inputs | 56 channels
Switch-to-ground (SG)28 channels | active-low, wake-up capable
Programmable switch (SP)16 channels | configurable active high/low, wake-up capable
Frequency input4 channels | wheel-speed, rotation-speed, or pulse signals
Analog input4 channels | 0–5 V DC
Resistive input4 channels | 2 × 100 Ω–200 kΩ; 2 × 100 Ω–2 kΩ
High-side Power Outputs | 36 channels
HSD 30 A1 channel | highest-priority load such as EPS
HSD 20 A3 channels | fans, pumps, and blowers
HSD 15 A10 channels | headlamps, wipers, horns, and heaters
HSD 5 A6 channels | turn, brake, reverse lamps, and DRL
HSD 3 A8 channels | marker/door lamps and ADAS/camera/IVI
HSD 1 A8 channels | LEDs, displays, and low-power modules
Other Outputs & Sensor Supplies
Half-bridge 4 A6 channels | bidirectional actuation; thermal design evaluated by load current, duty cycle, and operating conditions
Low-side driver 3 A8 channels | buzzers, relays, and low-power actuators
5 V sensor supply2 channels | 50 mA each with short/over-current protection
12 V sensor supply2 channels | 100 mA each with short/over-current protection
Output protectionOpen-load, short-to-ground/battery, over-current, and over-temperature detection
In-vehicle Networks
CAN FD3 channels | one wake-up channel; VCU, T-BOX, ADAS, and Inter-BCM
LIN Master1 channel | wake-up capable for HVAC and local subnetworks
100BASE-T11 optional channel | high-speed diagnostics and OTA
Address setting4-bit | identifies front/rear BCM nodes
Inter-BCMDedicated CAN FD protocol; signal synchronization requirement ≤ 100 ms
Processing Core & Safety
ModelBCM-168 2.0
Main processorNXP S32K344
CPU architectureArm Cortex-M7 + Cortex-M4
Memory4 MB Flash / 512 KB RAM
Hardware securityHSE, Secure Boot, and protected key storage
Functional-safety mechanismsLockstep, RAM/Flash ECC, window watchdog, voltage/clock monitoring
Firmware updateAB Swap dual-partition update with rollback
Power, Mechanical & Environment
Operating voltage9–32 V DC
Output capability2.5 kW output power; 105 A maximum normal current
Dimensions275.9 × 187.8 × 57 mm
Mass2010 g
ConnectorsTE / Molex / Phoenix
Input protectionReverse-polarity and automotive transient protection
Low-power modeSleep/LPOFF with CAN, LIN, ACC/IGN, and external-input wake-up
Operating temperature-40 °C to +85 °C
Storage temperature-40 °C to +85 °C

Ethernet is optional. Half-bridge thermal design is evaluated against load current, duty cycle, ambient temperature, and installation conditions. Application limits are defined in the program technical documentation.

Software Functions

A body domain controller for electric buses and commercial vehicles, integrating front/rear BCM, lighting, doors, HVAC, wipers, ADAS/IVI power, and high-density 24V load control.

Body Domain State Machine
Door Safety Logic with speed interlock and anti-pinch evaluation
Cooling / fan derating algorithm
Diagnostic Manager and fault aggregation
Lighting strategy engine
Wiper / washer logic with VCU-driven modes
ADAS / IVI power management with delay-off logic
Security Manager with MAC, freshness counter and authentication
Inter-BCM protocol handler

Need BCM architecture planning or custom I/O?

We can help plan BCM integration around vehicle platform topology, front/rear body layout, 24V loads, diagnostics, and Inter-BCM communication.

Contact us