Powertrain, generic · Hybrid propulsion

P0C89 Hybrid/EV Battery Temperature Sensor I Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P0C89 says sensor I delivers an electrically valid but implausible temperature. GM checks it against the average of the remaining sensors: the 2019 table 19OBDG02 fails it beyond 25 °C in 50 of 67 samples, Type B, two trips, and suspends the test while a low, high or communication fault is present; the 2016 Cadillac ELR table (16OBDG01) uses 20 °C. Bulletin 18-NA-342 calls it sensor 9 performance on the Volt and lists it among the codes cured by reprogramming the hybrid powertrain control module 2. Mitsubishi's 2018 Outlander PHEV treats it as rationality of channel [08], one check per drive after an hour parked, with a 13 °C limit held for 0.32 s. If a software update does not help, a misplaced or drifting thermistor is the likely cause.

Likely causes

Thermistor I drifted within its electrical range
Module software setting the code falsely, fixed by reprogramming (GM Volt)
Sensor I displaced from its measuring point
Real local heating at the cell group of sensor I

Symptoms

  • Check-engine or hybrid lamp, often after a long rest
  • Battery power reduced

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–2,500
Time0.5–5 h

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

Parts involved

hv battery temp sensor iwiring harnessbms

Related codes

P0C88P0C8AP0C8BP0C8CP0C82P0C8E

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