U01A9

Lost Communication With Hybrid/EV Battery Interface Control Module J

Severity

🔴 High

Can you drive?

Do not drive — repair immediately

Approx. repair cost

$167–556 (est.)

Symptoms

Check Engine light comes on
The car goes into emergency mode
Reduced engine power
Problems charging the hybrid battery
Error message on the dashboard

Causes

Open or short circuit in the CAN bus
Problems with power supply to the battery management module
Malfunction of the control module itself
Wiring harness damage
Software problems

How to Fix

Check the integrity of the CAN bus and connections
Check fuses and module power supply
Diagnose the battery control module
Check and update software
Repair only from an authorized dealer

Related codes

U01A8 U01AA U01AB