What are the common causes of P0B85?

An O terminal backing out of its connector. A broken strand in the O sense lead. An O tap that opens as the pack shifts. Corrosion bridging the O connector pins. A cold solder joint at the O module pin.

Road test while graphing O circuit voltage. Wiggle test the O connector and harness. Check O sense lead continuity while flexing it. Inspect the O pins for corrosion. Repair the O circuit if the signal cuts out. Clear the code and retest.

P0B85

Hybrid/EV Battery Voltage Sense O Circuit Intermittent/Erratic

System: Powertrain control (P code)
Lamp: Check Engine Light
Category: Powertrain - Hybrid Propulsion

What it means

P0B85 means Hybrid/EV Battery Voltage Sense O Circuit Intermittent/Erratic.

Check these first

An O terminal backing out of its connector
A broken strand in the O sense lead
An O tap that opens as the pack shifts
Corrosion bridging the O connector pins
A cold solder joint at the O module pin

What to do next

Road test while graphing O circuit voltage
Wiggle test the O connector and harness
Check O sense lead continuity while flexing it
Inspect the O pins for corrosion
Repair the O circuit if the signal cuts out
Clear the code and retest

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Updated

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