When your Prius hybrid system throws a warning light, it usually stores a diagnostic trouble code (DTC) that helps identify the problem. Here are the most common hybrid battery codes, what they mean, and how Hybrid Mechanics can help.

Common Prius Hybrid Battery Error Codes

P0A80 – Replace Hybrid Battery Pack
Meaning: The ECU has detected the battery can no longer provide consistent voltage and needs replacement.
Fix: Repair or replacement depending on the condition.

P0A7F – Battery Pack Deterioration
Meaning: The battery is weak but may still function with reduced efficiency.
Fix: Reconditioning and balancing often restore performance.

P3011–P3024 – Weak or Faulty Battery Module Detected
Meaning: These codes point to a specific module (cell pair) in the battery that is underperforming.
Fix: We replace the failing modules with tested OEM ones and rebalance the pack.

P0AFA – Hybrid Battery Voltage Sense Error
Meaning: Sensor readings are inconsistent—could be corrosion, a bad connection, or faulty wiring.
Fix: Clean and inspect connectors, recalibrate pack.

P0AC0 / P0A0D – Interlock or Isolation Faults
Meaning: Indicates a potential safety or connection issue, often from improper handling or wear.
Fix: Inspect wiring, relays, and bus bars. Repair or replace as needed.

What To Do If You See an Error Code

1. Don’t panic – Many issues can be fixed without full replacement.
2. Schedule a Diagnostic – We’ll scan the system, explain the issue, and recommend the right fix.
3. Stay on the road – If we need to take your battery, we’ll install a temporary one so you’re never without a car.