P0C9A code meaning
Hybrid/EV Battery Temperature Sensor L Circuit High
Powertrain system Generic code P0Cxx codes Check engine light
What P0C9A means
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.
P0C9A at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.5 to 5 hours
- Clears after repairAfter a drive cycle
Symptoms of P0C9A
- Battery-too-cold indication in mild conditions
- Electric power reduced, engine running more on plug-ins
Common causes of P0C9A
- Most likelyOpen circuit or unplugged connector at sensor L
- PossibleThermistor L open internally
- Less likelyCorroded terminal with very high contact resistance
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hv battery temp sensor lWiring harnessBms
What each part of P0C9A means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| C | Area: hybrid propulsion. |
| 9A | The exact fault in that area. |
What to do next
- Note P0C9A and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0C9A
What does P0C9A mean?
P0C9A means "Hybrid/EV Battery Temperature Sensor L Circuit High". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P0C9A?
Drive gently and only to a workshop. With P0C9A the car can go into limp mode (reduced power) to protect itself.
Will P0C9A fail an emissions test?
Yes, it can. P0C9A is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0C9A to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 5 hours of work. This is a job for a workshop.
Will P0C9A clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.