P0B19: Hybrid/EV Battery Pack Voltage Sense C Circuit

Voltage sense C is the third of up to four pack voltage measurements defined in SAE J2012. P0B19 is its general circuit code and sets when the battery controller finds this input electrically unusable, for instance open or without a valid raw value. Which measuring point a manufacturer assigns to C is its own choice. No manufacturer documents P0B19 publicly. GM shows the principle for channel A, checking pack-side voltage against limits and against the summed cell voltages (P0ABB to P0ABD). CARB requires battery voltage sensors of hybrid storage systems to be monitored as input components. The detailed fault types of channel C are P0B1A to P0B1D. High-voltage operation is usually limited.

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
Vehicle may not reach Ready or may shut down the high-voltage system

Most likely causes

Voltage sense lead C or its fuse open
Sense connector loose or corroded
Measurement input of the battery controller defective

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
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 P0B19 means

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

Frequently asked questions

Can I keep driving with code P0B19?

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 P0B19?

The most common causes are: voltage sense lead C or its fuse open; sense connector loose or corroded; measurement input of the battery controller defective.

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.