P0C9AHybrid/EV Battery Temperature Sensor L 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
- P0C9A is the high-voltage fault of sensor L: an open thermistor, a broken lead or a disconnected plug lets the bias resistor raise the input, and the reading looks like deep frost. GM's 2016 table 16OBDG02 sets it when 8 readings out of 10, taken every 100 ms, are colder than −69 °C; it is Type B and requires more than 10.2 V supply plus working communication. The 2012 Volt table treats readings below −40 °C, a raw count above 4,000, as failed. Mitsubishi assigns no code to sensor L. The controller then plans for a frozen battery, so electric power can be reduced and a plug-in may run its battery heater or engine. Check the plug at the monitoring board first; P0C99 is the short-circuit partner.
- What you may notice
- Battery-too-cold indication in mild conditions
- Electric power reduced, engine running more on plug-ins
- Likely causes
- LikelyOpen circuit or unplugged connector at sensor L
- PossibleThermistor L open internally
- RareCorroded terminal with very high contact resistance
- 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.