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Toyota Prius Software Error May Cause Power Loss
high How serious is it? About this label
Losing power while driving increases the risk of a crash. The notice does not tell owners to stop driving.
Key facts
| NHTSA campaign number | 21V734000 |
|---|---|
| Reported to NHTSA | Sep 22, 2021 |
| Manufacturer | Toyota Motor Engineering & Manufacturing |
| Part affected | Engine And Engine Cooling:engine:engine Control Module (ecu/ecm):software |
| Vehicles covered | 2 model/year combinations, model years 2022 |
| Do-not-drive advisory | No |
| Park-outside advisory | No |
| Repair | Free at any franchised dealer |
What's wrong, in plain English
In some Toyota Prius and Prius Prime vehicles, the computer that controls the engine has software that can mistakenly detect an error, even when nothing is actually wrong. When that happens, the computer can shut down the hybrid system. This causes the car to lose the power that normally drives the wheels, meaning the car can no longer move forward under its own power the way it normally would.
What you should do
2. Contact a Toyota dealer, or call Toyota customer service at 1-800-331-4331.
3. The software update is free.
Where do I find my VIN, and what do I tell the dealer?
Your VIN is the 17-character code on the lower left of the windshield, on your registration and usually on your insurance card. Enter it at nhtsa.gov/recalls to see whether this recall is still open on your car. When you call the dealer, say you have an open safety recall and give them NHTSA campaign number 21V734000. More in how recalls work.
Affected vehicles (2)
Who to contact
Toyota — official Toyota recall lookup
Customer service: 1-800-331-4331
The bigger picture
- Toyota Engine Recalls: Stalling, Coolant Leaks, and Drive Power Loss · all 7 Toyota recalls in this area
Other Toyota Prius recalls
- Jan 28, 2026Toyota Prius Rear Door May Open While Drivinghigh
- Oct 30, 2025Toyota, Lexus and Subaru rearview camera may freezemedium
- Jul 23, 2024Toyota accessory weight label may show wrong numberslow
- Apr 17, 2024Toyota Prius Rear Doors May Open Unexpectedlyhigh
- Dec 11, 2019Toyota Prius Instrument Display May Go Blankmedium
- Jul 24, 2019Toyota Prius, RAV4 Hybrid Brake Assist May Failhigh
Official notice
- Component
- ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM):SOFTWARE
- Summary
- Toyota Motor Engineering & Manufacturing (Toyota) is recalling certain 2022 Prius and Prius Prime vehicles. The Engine Control Unit (ECU) software may falsely detect an error and shut down the hybrid system, causing a loss of drive power.
- Safety risk
- A loss of drive power increases the risk of a crash.
- Remedy
- Dealers will update the ECU software, free of charge. Owner notification letters were mailed November 18, 2021. Owners may contact Toyota customer service at 1-800-331-4331. Toyota's number for this recall is 21TB07/21TA07.
Verify your specific vehicle by VIN at nhtsa.gov. Recall repairs are free of charge by law.