P0C8F: Hybrid/EV Battery Temperature Sensor J Circuit Low

P0C8F means the voltage on sensor J has dropped below its valid window. The NTC thermistor is powered via a pull-up resistor, so a grounded signal line reads as an absurdly hot cell group; low refers to the signal. GM's HPC2 table of 2019 (19OBDG02) converts the voltage and fails the test if the result is over 160 °C for 8 samples out of 10, sampled every 100 ms and rated Type B. The older 2012 Volt table judges all sensors together and fails them above 87.5 °C (raw count under 680) for 1.4 s of a 2 s window. On the 2018 Outlander PHEV, Mitsubishi logs a short of sensor [09] once the signal remains below 0.12 V, hotter than 125 °C, for 2 s. A genuinely overheating pack would instead set P0A7E. Expect reduced power and battery cooling running hard.

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 with clearly reduced electric power
Battery fan or chiller running constantly
Engine starts more often on plug-in hybrids

Most likely causes

Sensor J signal wire chafed and shorted to ground
Thermistor J shorted internally, for example after moisture
Monitoring board input pulling the line low

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
With the connector unplugged, check whether the signal wire is making contact with ground.
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 P0C8F means

P: Powertrain: engine and transmission
0: Generic code: same on every make
C: Subsystem depends on the code range
8F: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0C8F?

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 P0C8F?

The most common causes are: sensor J signal wire chafed and shorted to ground; thermistor J shorted internally, for example after moisture; monitoring board input pulling the line low.

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.