U0112: Lost Communication With Battery Energy Control Module B

U0112 is a network communication code that appears when the vehicle's communication bus loses contact with Battery Energy Control Module B. This module is part of the battery management system and monitors or controls battery energy on vehicles equipped with advanced electrical architectures, including hybrids and vehicles with intelligent charging systems. When the module stops responding on the bus, U0112 is set by another control unit that expected to hear from it.

The fault is usually down to a loss of power or ground to the module, a damaged or disconnected CAN bus connector at that module's location, wiring damage along the bus, or a failed module. Because this is a "B" module designation, it may be a secondary or auxiliary unit depending on the vehicle. Start by verifying the module has a solid power supply and the connectors are seated properly, then check for wiring damage along the relevant bus segments.

This code carries a low severity rating, but battery energy management is not something to ignore indefinitely. A loss of communication here can mean the vehicle is making charging and load decisions without full information, which may cause premature battery wear or inconsistent electrical behaviour over time. Get the fault investigated and the module communication restored before it compounds into something more involved.