P0BA6: Hybrid/EV Battery Voltage Sense V Circuit Low

A sense V reading that collapses towards zero produces P0BA6. The threshold depends on the system: GM's eAssist mild hybrid uses under 1.4 V in 7 of 10 samples with at least 8.8 V on the 12 V side, Type B, while GM's lithium-ion battery controllers of 2016 and 2019 go down to 0.2 V or less for 1.4 s within 2 s, Type A. The 16OBDG02 programme sets it below 0.20 V in 14 of 18 samples. Because these tests are blocked by an active open sense line fault, P0BA4 would be reported first if the lead were simply broken; P0BA6 alone tends to mean a short to a lower potential or a failed input. The driver sees a hybrid or EV warning and reduced power.

Symptoms

• MIL and service hybrid or EV system message
• Power limited, restart may be refused

Most likely causes

• Sense lead V shorted to ground or a lower cell
• Monitoring board input for channel V failed
• Cell V genuinely collapsed

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 P0BA6 means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• B: Subsystem depends on the code range
• A6: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0BA6?

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 P0BA6?

The most common causes are: sense lead V shorted to ground or a lower cell; monitoring board input for channel V failed; cell V genuinely collapsed.

Related codes

• P0BA4Hybrid/EV Battery Voltage Sense V Circuit
• P0BA5Hybrid/EV Battery Voltage Sense V Circuit Range/Performance
• P0BA7Hybrid/EV Battery Voltage Sense V Circuit High
• P0BA8Hybrid/EV Battery Voltage Sense V Circuit Intermittent/Erratic
• P0BA1Hybrid/EV Battery Voltage Sense U Circuit Low
• P0BABHybrid/EV Battery Voltage Sense W Circuit Low

Sources

• gsi.ext.gm.com: 13OBDG05C Hybrid Diagnostics
• gsi.ext.gm.com: 19OBDG01 Hybrid Diagnostics
• gsi.ext.gm.com: 16OBDG02 Hybrid Diagnostics

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.