Hybrid/EV Battery Voltage Isolation Sensor Circuit Intermittent/Erratic

Where it lives

For P0AAB, the circuit described runs through the sensor. The description of P0AAB reports a fault at the sensor.

Check these first

• A battery isolation sensor that fails when hot
• Corrosion at the sensor wiring or connectors
• A loose terminal at the sensor or control module
• Electrical interference on the sensor signal

What to do next

1. Read battery isolation sensor data on a scan tool
2. Wiggle test the sensor wiring and connectors
3. Look for noise sources near the sensor wiring
4. Measure sensor resistance when hot
5. Replace the sensor if the signal jumps
6. Clear the code and retest

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