P0B6A: Hybrid/EV Battery Voltage Sense J Circuit Low

A reading of almost zero on channel J points to the measurement, not to the cell, and that is what P0B6A records. In GM's lithium-ion systems (2016 and 2019 tables) the battery energy control module sets it at 0.2 V or less for 1.4 s within 2 s, Type A. The interesting part is what it ignores: while a module communication loss, an open sense line code, a balancing fault or an internal module fault is active, P0B6A stays silent so that the root cause is stored first. The 2012 two-mode hybrids look at nickel-metal hydride block 10 together with block 11, both below 2 V in 15 of 20 samples, Type B. Expect reduced or no electric drive until the circuit is repaired.

Symptoms

• Electric drive limited or unavailable
• MIL and battery warning message

Most likely causes

• Channel J lead chafed through and shorted to ground
• Damaged measuring input on the monitoring board
• Cell on channel J internally shorted

What to check, in order

Start with the simplest. You can tick off each step.

1. Read the codes with a hybrid-compatible scanner and write down the freeze frame data
2. With the connector unplugged, check whether the signal wire is making contact with ground.
3. Make sure the battery cooling air intake is clean
4. Check the 12 V auxiliary battery, which can also trigger warnings
5. Leave any high-voltage measurements to a specialized repair shop

Good to know

• It can trigger limp mode.
• It affects emissions.

What each character of P0B6A means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• B: Subsystem depends on the code range
• 6A: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0B6A?

If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

What causes code P0B6A?

The most common causes are: channel J lead chafed through and shorted to ground; damaged measuring input on the monitoring board; cell on channel J internally shorted.

Related codes

• P0B68Hybrid/EV Battery Voltage Sense J Circuit
• P0B69Hybrid/EV Battery Voltage Sense J Circuit Range/Performance
• P0B6BHybrid/EV Battery Voltage Sense J Circuit High
• P0B6CHybrid/EV Battery Voltage Sense J Circuit Intermittent/Erratic
• P0B65Hybrid/EV Battery Voltage Sense I Circuit Low
• P0B6FHybrid/EV Battery Voltage Sense K Circuit Low

Sources

• gsi.ext.gm.com: 19OBDG01 Hybrid Diagnostics
• gsi.ext.gm.com: 16OBDG01 Hybrid Diagnostics
• gsi.ext.gm.com: 12OBDG06 Hybrid Diagnostics
• law.cornell.edu: 13 CCR 1968.2

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.