P0C8CHybrid/EV Battery Temperature Sensor I Circuit Intermittent/Erratic
- 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
- P0C8C reports that sensor I changes faster and more often than any real battery temperature could. GM is the only maker that publishes the test: in 19OBDG02, the 2019 hybrid powertrain control module 2 table, each 10-sample window at 100 ms per sample is scored by the summed absolute change of the reading, a score above 10 counts as a failed window, and 4 failed windows out of 5 set the code, Type B, two trips, with system voltage above 10.2 V and no communication fault to the battery interface module. The 2018 table 18OBDG02 contains the same rule. Unlike P0C8A and P0C8B the value never leaves its valid range. Look for a fretting terminal or a wire broken inside its insulation; several erratic sensors at once point to the sensing board.
- What you may notice
- Warning lamp appearing now and then
- Sensor I value jumping in live data
- Short phases of reduced power
- Likely causes
- LikelyFretting or loose terminal on the sensor I connector
- PossibleSensor I wire broken inside its insulation
- RareSensing board with unstable supply or ground
- 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.