P2C85

Hybrid/EV Battery Voltage External Isolation Fault

Severity

🚨 Critical

Can you drive?

Do not drive — repair immediately

Approx. repair cost

$167–889 (est.)

Symptoms

Check Engine light comes on
High voltage system fault warning appears
Reduced power or hybrid system failure
The car may go into emergency mode
Possible problems with battery charging

Causes

Damage to the insulation of high-voltage cables
Corrosion of high voltage connectors
Moisture ingress into high voltage components
High voltage battery fault
Problems with insulation sensors

How to Fix

Visual inspection of high voltage cables and connectors
Checking the insulation condition of high voltage components
High voltage battery diagnostics
Checking insulation sensors
Repair or replace damaged components
Repair only from an authorized dealer

Related codes

P0AA6 P1A00 P2C84