P0AAA

Hybrid/EV Battery Voltage Isolation Sensor Circuit High

Severity

🚨 Critical

Can you drive?

Do not drive — repair immediately

Approx. repair cost

$56–167 (est.)

Symptoms

Check Engine light comes on
Reduced vehicle power
Error message on the dashboard
Limitation of hybrid system operation
The car may go into emergency mode

Causes

Battery isolation sensor malfunction
Open or short circuit in the sensor circuit
Damage to the insulation of high-voltage cables
High Voltage System Grounding Problems
Hybrid ECU malfunction

How to Fix

Check the continuity of the insulation sensor circuit
Check the insulation resistance of the high voltage system
Test battery isolation sensor
Check connections and grounding of the high voltage system
Repair only from an authorized dealer

Related codes

P0AAB P0AAC P0AAD