P0CAF code meaning
Hybrid/EV Battery Temperature Sensor N Circuit Low
Powertrain system Generic code P0Cxx codes Check engine light
What P0CAF means
P0CAF sets when the signal of sensor N is pulled under its lower voltage limit. A ground fault in the lead or a shorted thermistor causes this, and because the NTC sensor works against a pull-up resistor the controller interprets it as an implausibly hot module. GM's 2017 HPC2 table 17OBDG02 records a failure once the computed temperature tops 160 °C in 8 of 10 readings, classed as Type B, provided the supply is above 10.2 V and code U179C is not active. The 2012 Volt table accepts N up to 87.5 °C, equal to a raw value from 680 upward. On the Outlander PHEV, Mitsubishi calls it a short of sensor [13], judged below 0.12 V for 2 s and fixed by replacing the battery module or cell monitoring unit. Genuine pack overheating is reported as P0A7E.
P0CAF at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor1 to 5 hours
- Clears after repairAfter a drive cycle
Symptoms of P0CAF
- Warning lamp and markedly reduced battery power
- Battery cooling running at full effort
Common causes of P0CAF
- Most likelySensor N lead shorted to ground
- PossibleThermistor N internally shorted
- Less likelyMeasuring input of the cell monitoring unit defective
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 nWiring harnessBms
What each part of P0CAF 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. |
| AF | The exact fault in that area. |
What to do next
- Note P0CAF 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 P0CAF
What does P0CAF mean?
P0CAF means "Hybrid/EV Battery Temperature Sensor N Circuit Low". P0CAF sets when the signal of sensor N is pulled under its lower voltage limit. It is a generic code, so it means the same on every make.
Is it safe to drive with P0CAF?
Drive gently and only to a workshop. With P0CAF the car can go into limp mode (reduced power) to protect itself.
Will P0CAF fail an emissions test?
Yes, it can. P0CAF 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 P0CAF to fix?
Difficulty: workshop only. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will P0CAF 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.