P0AA8

Hybrid/EV Battery Voltage Isolation Sensor Circuit Range/Performance

Severity

🚨 Critical

Can you drive?

Do not drive — repair immediately

Approx. repair cost

$56–278 (est.)

Symptoms

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

Causes

Insulation sensor fault
Damage to wiring or connectors
High voltage battery insulation problems
Short circuit in high voltage system
Problems with the hybrid system control module

How to Fix

Check the condition of the insulation sensor
Inspect wiring and connectors for damage
Check battery insulation resistance
Scan for other trouble codes
Repair only from an authorized dealer

Related codes

P0AA6 P0AA7 P0AA9