Powertrain, generic · Hybrid propulsion

P0C86 Hybrid/EV Battery Temperature Sensor F/G Correlation

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P0C86 compares the neighbouring battery temperature sensors F and G with each other. After the pack has rested, both should settle to nearly the same value; a persistent gap means at least one reads wrong although neither circuit is open or shorted. No manufacturer documents P0C86 publicly. GM and Mitsubishi test plausibility against the pack average instead and store the single sensor: GM's 2019 table 19OBDG02 uses a 25 °C margin for P0C34 (sensor 6) and P0C7D (sensor 7), Mitsubishi's 2018 Outlander PHEV 13 °C after 3,600 s soak. CARB lets manufacturers define the rationality checks for such inputs. If a real gap shows, uneven cooling between the two module groups deserves a look. The E/F pair is P0C72, G/H is P0C87.

Likely causes

Thermistor F or G drifted without an electrical fault
Sensor F or G no longer in contact with its module
Real temperature difference between the two module groups
Battery management calibration with an overly narrow window

Symptoms

  • Hybrid or EV warning lamp
  • Somewhat reduced battery power
  • Sensors F and G far apart in live data after a cold soak

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 fhv battery temp sensor gbms

Related codes

P0C72P0C87P0C34P0C7DP0C33P0C7C

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