P0B6F: Hybrid/EV Battery Voltage Sense K Circuit Low

GM's BAS Plus mild hybrid, the eAssist system in table 13OBDG05C, gives P0B6F a simple rule: if the cell sense line for channel K measures below 1.4 V in 7 of 10 samples at 200 ms while the 12 V supply is above 8.8 V, the code is stored as Type B, two trips. Since a lithium-ion cell in use never falls that low, the value must come from a short or a failed input. GM's later battery energy control modules work with 0.2 V and a 1.4 s window, Type A, and the 2012 two-mode trucks with nickel-metal hydride blocks 11 and 12, both under 2 V. The driver typically sees a hybrid warning and loses electric assist; the engine takes over more of the work.

Symptoms

• Hybrid warning and MIL after the second trip
• Auto stop and electric assist disabled

Most likely causes

• Channel K sense line shorted to ground or a lower tap
• Failed measuring input in the battery interface module
• Blown protective element in the sense line

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 P0B6F means

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

Frequently asked questions

Can I keep driving with code P0B6F?

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 P0B6F?

The most common causes are: channel K sense line shorted to ground or a lower tap; failed measuring input in the battery interface module; blown protective element in the sense line.

Related codes

• P0B6DHybrid/EV Battery Voltage Sense K Circuit
• P0B6EHybrid/EV Battery Voltage Sense K Circuit Range/Performance
• P0B70Hybrid/EV Battery Voltage Sense K Circuit High
• P0B71Hybrid/EV Battery Voltage Sense K Circuit Intermittent/Erratic
• P0B6AHybrid/EV Battery Voltage Sense J Circuit Low
• P0B74Hybrid/EV Battery Voltage Sense L Circuit Low

Sources

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