P0BC5: Hybrid/EV Battery Temperature Sensor E Circuit High

P0BC5 reports that battery temperature sensor E delivers a voltage above its valid range. With GM's NTC sensors that reads as extreme cold, pointing to an open wire, a backed-out pin at the sensing board or a cracked thermistor. GM's 2016 table sets it below -69 °C in 8 of 10 samples, the 2011 Volt table and GM's 2019 battery module table below -40 °C for 1.4 s within 2 s, and the eAssist mild hybrid above 4.63 V, about -45 °C, in 7 of 10 samples; all Type B, two trips. On the Chevrolet Volt, bulletin 18-NA-342 links these codes to a Battery Too Cold message at ambient temperatures above -25 °C and prescribes reprogramming. Its counterpart is P0BC4. A pack the controller believes frozen gets strict charge and power limits.

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, plug in to warm message
Very limited power or charging

Most likely causes

Open sensor E wire or backed-out pin at the sensing board
Cracked or open thermistor E
Module software misreading in the cold (GM Volt, reprogramming)

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
Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
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 P0BC5 means

P: Powertrain: engine and transmission
0: Generic code: same on every make
B: Subsystem depends on the code range
C5: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0BC5?

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 P0BC5?

The most common causes are: open sensor E wire or backed-out pin at the sensing board; cracked or open thermistor E; module software misreading in the cold (GM Volt, reprogramming).

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.