P0AAB

Hybrid/EV Battery Voltage Isolation Sensor Circuit Intermittent/Erratic

Severity

🔴 High

Can you drive?

Do not drive — repair immediately

Approx. repair cost

$56–167 (est.)

Symptoms

Check Engine Light Illuminates
Hybrid system power reduction
High voltage battery charging failure
Warning messages on the dashboard
The car goes into emergency mode

Causes

Broken or damaged insulation sensor wires
Corrosion of contacts in connectors
Malfunction of the insulation sensor itself
High Voltage System Grounding Problems
Hybrid control module failure

How to Fix

Perform a visual inspection of the sensor wiring harness
Check the condition of connectors and contacts
Measure the insulation resistance with a multimeter
Scan the memory of other modules for related codes
Replace insulation sensor if necessary
Diagnosis and repair must be performed by a certified hybrid technician.

Related codes

P0AAC P0AAD P0AAE