What are the common causes of P0C85?

A loose sensor H connector. Chafed sensor H wiring. A sensor H thermistor breaking down when hot. Water in the sensor H connector. Electrical interference on the sensor H line.

Road test and watch hybrid battery temperature sensor H. Wiggle test the sensor H connector and harness. Heat the pack area and watch for a dropout. Inspect the sensor H wiring for chafing. Replace sensor H if the signal cuts out. Clear the code and retest.

P0C85

Hybrid/EV Battery Temperature Sensor H Circuit Intermittent/Erratic

System: Powertrain control (P code)
Lamp: Check Engine Light
Category: Powertrain - Fuel/Air Metering

What it means

P0C85 means Hybrid/EV Battery Temperature Sensor H Circuit Intermittent/Erratic.

Where it lives

For P0C85, the circuit described runs through the sensor. The description of P0C85 reports a fault at the sensor.

Check these first

A loose sensor H connector
Chafed sensor H wiring
A sensor H thermistor breaking down when hot
Water in the sensor H connector
Electrical interference on the sensor H line

What to do next

Road test and watch hybrid battery temperature sensor H
Wiggle test the sensor H connector and harness
Heat the pack area and watch for a dropout
Inspect the sensor H wiring for chafing
Replace sensor H if the signal cuts out
Clear the code and retest

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Updated

Generic SAE J2012 definition. Last updated 2026-10-10.