P0CAF: Hybrid/EV Battery Temperature Sensor N Circuit Low

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.

High severity. Can I keep driving?If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

Symptoms

Warning lamp and markedly reduced battery power
Battery cooling running at full effort

Most likely causes

Sensor N lead shorted to ground
Thermistor N internally shorted
Measuring input of the cell monitoring unit defective

What to check, in order

Start with the simplest. You can tick off each step.

Read the codes with a hybrid-compatible scanner and write down the freeze frame data
With the connector unplugged, check whether the signal wire is making contact with ground.
Make sure the battery cooling air intake is clean
Check the 12 V auxiliary battery, which can also trigger warnings
Leave any high-voltage measurements to a specialized repair shop

Good to know

It can trigger limp mode.
It affects emissions.

What each character of P0CAF means

P: Powertrain: engine and transmission
0: Generic code: same on every make
C: Subsystem depends on the code range
AF: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0CAF?

If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

What causes code P0CAF?

The most common causes are: sensor N lead shorted to ground; thermistor N internally shorted; measuring input of the cell monitoring unit defective.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.