P0B1F: Hybrid/EV Battery Pack Voltage Sense D Circuit Range/Performance

P0B1F says pack voltage measurement D is electrically present but disagrees with what the controller expects, typically the sum of cell voltages or a parallel pack measurement. It is a plausibility fault, not an open or shorted circuit. No manufacturer documents P0B1F publicly. GM's analogous channel A check, P0ABB, fails at a deviation above 12 V from the summed cell voltages for 20 of 25 samples at 25 ms, Type A, one trip. CARB requires rationality checks for battery voltage sensors of hybrid storage systems. Circuit faults of channel D use P0B1E, P0B20 and P0B21. With a doubtful pack voltage the controller narrows the usable battery window and limits power.

High severity. Can I keep driving?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.

Symptoms

MIL and hybrid/EV system warning on
Implausible state-of-charge or range display
Battery power limited, reduced electric drive or assist

Most likely causes

Drift or calibration error of measurement channel D
Cell voltage acquisition faulty, reference sum wrong
Increased resistance at sense terminals
Battery controller software needs an update

What to check, in order

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

Read the codes with a hybrid-compatible scanner and write down the freeze frame data
Compare the reading with other engine data while varying the engine speed.
Make sure the battery cooling air intake is clean
Check the 12 V auxiliary battery, which can also trigger warnings
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 P0B1F means

P: Powertrain: engine and transmission
0: Generic code: same on every make
B: Subsystem depends on the code range
1F: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0B1F?

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 P0B1F?

The most common causes are: drift or calibration error of measurement channel D; cell voltage acquisition faulty, reference sum wrong; increased resistance at sense terminals.

Related codes

Sources

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.