P0B15: Hybrid/EV Battery Pack Voltage Sense B Circuit Range/Performance

P0B15 marks pack voltage measurement B as electrically valid but implausible: the value lies within the sensor range yet does not match a reference, typically the sum of the cell voltages or another pack measurement. No manufacturer documents this code publicly. GM shows the principle on channel A: P0ABB fails when pack voltage and summed cell voltages differ by more than 12 V, 20 of 25 samples at 25 ms, Type A, one trip. CARB demands rationality checks for battery voltage sensors of the hybrid storage system. Hard circuit faults of channel B are P0B14, P0B16 and P0B17. Because state of charge and cell protection rely on this value, the controller restricts power or charging.

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
Battery power limited, reduced electric drive or assist
Implausible state-of-charge or range display

Most likely causes

Drift or calibration error of measurement channel B
Faulty cell voltage acquisition distorts the reference sum
Increased contact 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 P0B15 means

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

Frequently asked questions

Can I keep driving with code P0B15?

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 P0B15?

The most common causes are: drift or calibration error of measurement channel B; faulty cell voltage acquisition distorts the reference sum; increased contact 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.