P0C84Hybrid/EV Battery Temperature Sensor H Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P0C84 is set when the sensor H line sits too high in voltage, which the controller converts into an impossible cold reading. The pull-up drives an interrupted circuit upward, so an open wire, a pushed-out pin or a broken thermistor are the classic triggers. In GM's 2012 Volt table (12OBDG01A) the limit is below −40 °C, an ADC count above 4000, held for 1.4 s within a 2 s window; the 2019 table 19OBDG02 uses −69 °C in 8 of 10 samples, Type B. Mitsubishi's Outlander PHEV of 2022 sees an open of sensor [07] above 3.97 V, below −62 °C, for 2 s. A cold-weather complaint with a Battery Too Cold message on the Volt may be software, per bulletin 18-NA-342. The short-to-ground counterpart is P0C83.
- What you may notice
- Battery-too-cold message in mild weather
- Electric drive limited or unavailable
- Likely causes
- LikelyBroken wire or backed-out pin in the sensor H circuit
- PossibleThermistor H open
- RareFalse set by battery module software (GM Volt, 18-NA-342)
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €100 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.