U01A1

Lost Communication With Hybrid/EV Battery Interface Control Module B

Severity

🔴 High

Can you drive?

Do not drive — repair immediately

Approx. repair cost

$56–278 (est.)

Symptoms

Check Engine light comes on
The car goes into emergency mode
Reduced engine power
Problems charging the hybrid battery
Inability to switch between driving modes

Causes

Open or short circuit in wiring harness
Hybrid battery control module malfunction
Main control unit malfunction
Problems with power supply or module ground
Corrosion of contacts or connectors

How to Fix

Check the integrity of the wiring harness between the modules
Check the power and ground of the battery control module
Inspect connectors for corrosion or damage
Scan the battery management module for additional errors
Repair only from an authorized dealer

Related codes

U01A0 U01A2 U01A3