What are the common causes of P0BA9?

A failed hybrid battery interface control module. An open or short in the battery voltage sense W circuit. A poor electrical connection at the interface control module. A failed hybrid battery pack.

Read hybrid battery block voltages on a scan tool. Inspect the battery interface control module connectors. Test the voltage sense W circuit for open and short faults. Compare the battery block voltages against each other. Replace the interface control module or battery section if the fault stays. Clear the code and retest.

P0BA9

Hybrid/EV Battery Voltage Sense W Circuit

System: Powertrain control (P code)
Lamp: Check Engine Light
Category: Powertrain - Hybrid Propulsion

What it means

P0BA9 means Hybrid/EV Battery Voltage Sense W Circuit.

Check these first

A failed hybrid battery interface control module
An open or short in the battery voltage sense W circuit
A poor electrical connection at the interface control module
A failed hybrid battery pack

What to do next

Read hybrid battery block voltages on a scan tool
Inspect the battery interface control module connectors
Test the voltage sense W circuit for open and short faults
Compare the battery block voltages against each other
Replace the interface control module or battery section if the fault stays
Clear the code and retest

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Updated

Generic SAE J2012 definition. Last updated 2026-10-10.