P0A80: Replace Hybrid Battery Pack
Severity: high
What it means: The hybrid battery management system sees voltage or resistance differences between battery blocks that point to one or more weak cells in the high-voltage pack.
Safe to drive? Usually drivable for a while with less power and mileage, but the pack can get worse quickly and the hybrid system may shut down. Plan a repair soon.
Common symptoms
- Check-engine light and red triangle master warning
- Lower fuel economy
- Weak acceleration
- Battery gauge swinging quickly between full and low
Likely causes, ranked
- Weak or failed cells in the hybrid batteryShop
- Clogged battery cooling fan or intake causing overheatingDIY
- Battery voltage sensor or wiring faultShop
- Corroded busbar connectionsShop
Vehicle-specific notes
- :
What it means: The hybrid battery management system sees voltage or resistance differences between battery blocks that point to one or more weak cells in the high-voltage pack.
Severity: High. Safe to drive? Usually drivable for a while with less power and mileage, but the pack can get worse quickly and the hybrid system may shut down. Plan a repair soon.
DIY or shop?
Cleaning the battery fan intake is DIY. Pack replacement or rebuild involves high voltage and is shop work.
Vehicle notes
- Common on aging 2004–2009 Prius. Owners compare refurbished, aftermarket new and Toyota packs.
Before you replace parts
- Read all stored codes, including detail (INF) codes on Toyota hybrids.
- Check your VIN for recalls, service bulletins and extended coverage.
- Clear the code only after a repair, then confirm it stays off.
Safety / mechanic note
Verify with a mechanic. Hybrid systems carry dangerous high voltage. A code points to a circuit or system, not always a specific part.