P0CB6: Hybrid/EV Battery Temperature Sensor O Circuit Intermittent/Erratic

P0CB6 targets a sensor O signal that jitters or jumps instead of changing smoothly. Only GM's later HPC2 tables (16OBDG02 to 19OBDG02) define it: every 100 ms a sample is taken, the absolute steps between ten consecutive samples are summed, and a sum above 10 marks that window as failed. Four failed windows out of five set the code as Type B, so the lamp follows on the second trip; the test needs more than 10.2 V and a working link to the battery interface module. The earlier Volt tables of 2011 and 2012 had no such code for O, and Mitsubishi uses none for its pack sensors. Because the reading can stay inside the valid band, P0CB4 and P0CB5 may never appear. Shaking the harness while watching live data, and the freeze-frame record, help to find a fretting contact or cracked solder joint.

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

Warning lamp that comes and goes
Sensor O value jumping in live data

Most likely causes

Fretting or loose terminal in the sensor O circuit
Cracked solder joint or trace on the sensing board
Chafed lead touching ground only under vibration

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
Gently move the wiring with the engine running and watch whether the reading changes.
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 P0CB6 means

P: Powertrain: engine and transmission
0: Generic code: same on every make
C: Subsystem depends on the code range
B6: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0CB6?

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 P0CB6?

The most common causes are: fretting or loose terminal in the sensor O circuit; cracked solder joint or trace on the sensing board; chafed lead touching ground only under vibration.

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.