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.
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
- Hybrid or EV warning lamp
- Somewhat reduced battery power
- Sensors F and G far apart in live data after a cold soak
Most 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
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- It can trigger limp mode.
- It affects emissions.
What each character of P0C86 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- C: Subsystem depends on the code range
- 86: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0C86?
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 P0C86?
The most common causes are: 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.
Related codes
- P0C72Hybrid/EV Battery Temperature Sensor E/F Correlation
- P0C87Hybrid/EV Battery Temperature Sensor G/H Correlation
- P0C34Hybrid/EV Battery Temperature Sensor F Circuit Range/Performance
- P0C7DHybrid/EV Battery Temperature Sensor G Circuit Range/Performance
- P0C33Hybrid/EV Battery Temperature Sensor F Circuit
- P0C7CHybrid/EV Battery Temperature Sensor G Circuit
Sources
- gsi.ext.gm.com: 19OBDG02 Hybrid Diagnostics
- mitsubishitechinfo.com: M154940770001700USA
- law.cornell.edu: 13 CCR 1968.2
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.