Code result

U0111

Lost Communication with Battery Energy Control Module A

High severity

What it means

The Battery Energy Control Module has stopped transmitting on the vehicle data bus, so other control units no longer receive its messages. High-voltage battery-management data is lost; the hybrid/EV system may disable the drive. Typical causes are loss of power or ground at the module, an open or shorted CAN/LIN bus wire, a connector fault, or an internal module failure.

Is it safe to drive?

No — stop driving

This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly.

Most likely causes

  • BMS unpowered (12 V supply)

    high

    One of the most commonly reported causes for this code — check this first.

  • CAN wiring to BMS broken

    medium

    A plausible cause — test and verify before replacing parts.

  • Gateway module routing CAN messages incorrectly

    low

    Less common, but worth ruling out after the more likely causes.

Get the full diagnosis

Add your vehicle and see step-by-step repair help, recalls, and TSBs in Wrenchify.

Diagnose U0111 free

No credit card required