Powertrain, generic · Hybrid propulsion

P0C87 Hybrid/EV Battery Temperature Sensor G/H Correlation

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P0C87 checks that battery temperature sensors G and H tell a consistent story. The controller would set it when, after enough rest for the pack to equalise, the two values remain apart by more than a calibrated margin. No manufacturer documents this pair code publicly. In the Volt, GM numbers G and H as sensors 7 and 8 and, in its 2012 table 12OBDG01A, compares each one with the average of the others after more than 21,600 s off, failing it beyond 25.3 °C as P0C7D or P0C82, Type B. Mitsubishi's 2022 Outlander PHEV logs sensors [06] and [07] the same way against a 13 °C limit. A pair code cannot say which of the two is wrong, so live data after a cold soak decides. The neighbouring pair code is P0C86 (F/G).

Likely causes

Thermistor G or H drifted while staying in range
Sensor G or H detached from its cell group
Real temperature gap from a weak cell group or blocked cooling
Battery module software needing an update

Symptoms

  • Hybrid or EV warning lamp
  • Reduced charge and discharge power

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–2,500
Time0.5–6 h

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

Parts involved

hv battery temp sensor ghv battery temp sensor hbms

Related codes

P0C86P0C72P0C7DP0C82P0C7CP0C81

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