Powertrain, generic · Hybrid propulsion

P0CAF Hybrid/EV Battery Temperature Sensor N Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

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.

Likely causes

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

Symptoms

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

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€150–3,000
Time1–5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

hv battery temp sensor nwiring harnessbms

Related codes

P0CB0P0CAEP0CADP0CB1P0A7EP0CAA

References: gsi.ext.gm.com, gsi.ext.gm.com, mitsubishitechinfo.com.