Two Wheeler Body Control Module

Short Circuit & Battery Protection; Helps Reduce Costs for Flasher & Starter Interlock Circuit
Overview

A Body Control Module (BCM) is used in modern bikes to provide robust protection against the faults that normally occur in two-wheelers.

Short Circuit Protection

The most frequent problem in two wheelers is short circuiting of various loads, which causes burning of the entire wiring harness of the vehicle. The BCM provides short circuit protection and auto restart of the load to overcome this issue.

  • If any load gets short circuited for any reason, the BCM will turn OFF that particular load.
  • After a pre-defined time, the BCM attempts to turn ON the load again.
  • If a short circuit condition occurs consecutively for a predefined number of times, the BCM turns OFF the load until the next power recycle.

This behavior helps to protect against burning of the wire harness, extends battery life, and improves vehicle durability.

Switch Failure Prevention

Another major issue encountered with two wheelers is the failure of switches, which is mainly caused by high in-rush current and arcing at the contacts of the switches.

  • In the BCM, switches are monitored continuously under the ON condition.
  • The load gets turned on only once the BCM detects that the switch is turned ON.

This behavior helps prevent the arcing at contacts since the current starts flowing only after the switch gets closed completely. No heavy current flows while turning ON the switch, which prevents arcing.

Additional Protection Features

  • Flasher and Starter Interlock Circuit Cost Reduction
    The BCM helps reduce cost on the flasher and starter interlock circuit. The BCM can double the flash rate of turn indicators in case of low load detection (e.g., failure of indicator lamp).
  • Anti-Crank Protection
    The BCM also prevents anti-cranking of the starter if the engine is already in running mode.
  • Headlamp RPM Interlock Battery Protection
    The RPM interlock for headlamp feature helps reduce draining of the battery if the user accidentally keeps the headlamp switch in the ON position while the engine is turned OFF.

Block Diagram

Key Features
  • Short circuit protection & auto restart of load
  • Constant monitoring of switches under ON condition
  • Additional features like doubling flash rate & anti-cranking of starter are available
Recommended Products
  • Microcontroller: RL78/F12 (R5F1096A)
  • IPD: UPD166028 (Quad channel)
  • IPD: UPD166033 (Single channel)
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