P0AA7

Hybrid/EV Battery Voltage Isolation Sensor Circuit

Severity

🔴 High

Can you drive?

Do not drive — repair immediately

Approx. repair cost

$56–167 (est.)

Symptoms

Check Engine light comes on
Hybrid system power reduction
Error message on display
Disabling the High Voltage System
Increased fuel consumption (in hybrids)

Causes

Voltage insulation sensor failure
Open or short circuit in the sensor circuit
Problems with the high voltage system wiring harness
Battery management module malfunction
Contact corrosion in a high voltage system

How to Fix

Check the continuity of the insulation sensor circuit
Test voltage insulation sensor
Inspect the high voltage system wiring harness
Check connections and contacts
Replace the faulty sensor if necessary
Repair only from an authorized dealer

Related codes

P0AA6 P0AA8 P0AA9