Powertrain, generic · Hybrid propulsion

P0C8F Hybrid/EV Battery Temperature Sensor J Circuit Low

Check engine lightOn

EmissionsRelevant

Drive cycleRequired

Limp modePossible

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.

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

Symptoms

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

Repair estimate

DifficultyShop_onlyWorkshop job

Parts and labour€150–2,500

Time1–5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

hv battery temp sensor jwiring harnessbms

References: gsi.ext.gm.com, gsi.ext.gm.com, mitsubishitechinfo.com.