P0BC3: Hybrid/EV Battery Temperature Sensor E Circuit Range/Performance

P0BC3 is the plausibility check for battery temperature sensor E, GM's sensor 5: its reading is compared with the other pack sensors, which should agree closely. GM's 2016 hybrid table fails it when E is more than 25 °C away from the average of the others in 50 of 67 samples; the 2018 CT6 plug-in table more than 20 °C for 5 s within 6.7 s; the eAssist mild hybrid (13OBDG05C) allows only 8.55 °C, and only after the module has been off for more than six hours. All are Type B, two trips. The check is suspended while circuit codes are active, so it points to a sensor that reads wrongly but in range, or to a real hot spot. Volt bulletin 18-NA-342 counts it among codes that set falsely in cold weather and fixes them by reprogramming.

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 on after two trips
Battery too cold or reduced power message
Limited charge and discharge power

Most likely causes

Sensor E drifting or poorly seated on its cell group
Module software setting the code falsely in the cold (GM Volt)
Real local hot spot from a weak cell group or blocked airflow

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 P0BC3 means

P: Powertrain: engine and transmission
0: Generic code: same on every make
B: Subsystem depends on the code range
C3: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0BC3?

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 P0BC3?

The most common causes are: sensor E drifting or poorly seated on its cell group; module software setting the code falsely in the cold (GM Volt); real local hot spot from a weak cell group or blocked airflow.

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.