P0C8BHybrid/EV Battery Temperature Sensor I 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
- P0C8B covers a sensor I signal stuck above its valid voltage, which the controller interprets as extreme cold. An interrupted circuit lets the pull-up lift the line, so the root cause is usually an open connection or a failed thermistor rather than the weather. On the 2016 Cadillac ELR (16OBDG01) GM fails it below −40 °C, an ADC count above 3992, for 1.4 s within 2 s, two trips. Mitsubishi's 2018 Outlander PHEV declares channel [08] open beyond 3.97 V, colder than −62 °C, held 2 s. For the Volt, bulletin 18-NA-342 lists it as sensor 9 circuit high voltage among codes that can come with a Battery Too Cold message above −25 °C and recommends new module software. The short-circuit counterpart is P0C8A.
- What you may notice
- Battery-too-cold message although outside temperature is mild
- Electric drive limited or unavailable
- Battery heater running unnecessarily
- Likely causes
- LikelyOpen wire or loose connector in the sensor I circuit
- PossibleThermistor I open
- RareBattery module software causing false cold readings (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.