U01AC

Lost Communication With Hybrid/EV Battery Interface Control Module M

Severity

🚨 Critical

Can you drive?

Do not drive — repair immediately

Approx. repair cost

$167–889 (est.)

Symptoms

Check Engine Light Is On
The car goes into emergency mode
Reduced power or inability to start
Errors in the hybrid/electric powertrain system
Lack of battery status information on the dashboard

Causes

Broken or damaged wires in the communication circuit
Oxidation or damage to connectors
Battery management module malfunction
Module power problems
Software failure in the control module

How to Fix

Check the integrity of the wiring harness and connectors
Check fuses and relays associated with the module
Diagnose the battery management module for errors
If necessary, reflash or replace the module
Repair only from an authorized dealer

Related codes

U01AB U01AD U0100