Powertrain, generic · Hybrid propulsion

P0C84 Hybrid/EV Battery Temperature Sensor H Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P0C84 is set when the sensor H line sits too high in voltage, which the controller converts into an impossible cold reading. The pull-up drives an interrupted circuit upward, so an open wire, a pushed-out pin or a broken thermistor are the classic triggers. In GM's 2012 Volt table (12OBDG01A) the limit is below −40 °C, an ADC count above 4000, held for 1.4 s within a 2 s window; the 2019 table 19OBDG02 uses −69 °C in 8 of 10 samples, Type B. Mitsubishi's Outlander PHEV of 2022 sees an open of sensor [07] above 3.97 V, below −62 °C, for 2 s. A cold-weather complaint with a Battery Too Cold message on the Volt may be software, per bulletin 18-NA-342. The short-to-ground counterpart is P0C83.

Likely causes

Broken wire or backed-out pin in the sensor H circuit
Thermistor H open
False set by battery module software (GM Volt, 18-NA-342)

Symptoms

  • Battery-too-cold message in mild weather
  • Electric drive limited or unavailable

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–2,500
Time0.5–5 h

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

Parts involved

hv battery temp sensor hwiring harnessbms

Related codes

P0C83P0C82P0C81P0C85P0C7FP0C8B

References: gsi.ext.gm.com, gsi.ext.gm.com, mitsubishitechinfo.com, static.nhtsa.gov.