Toyota is recalling 16,679 units of the 2021 RAV4 Prime plug-in hybrid due to a software logic issue that can potentially occur in limited circumstances. The Hybrid Vehicle Control ECU (HEV ECU) contains programming management parameters for the high voltage hybrid battery that ensures safe operation and protects the battery.
It has been found that when a driver has been in EV mode in cold temperatures and presses the accelerator pedal rapidly, the battery voltage can drop below a safe threshold. If that happens, the vehicle will display a warning message before turning off the hybrid system, which will turn off the vehicle. If this occurs at higher speeds, the occupants face a greater risk of a collision.
Toyota's Defect Report filed with the National Highway Traffic Safety Administration notes that the first reported instance of the event came from Europe in March 2022. While all recalled vehicles have the software in question, not all vehicles they were sold in the US Also, no other Toyota or Lexus products use the same HEV ECUs. With only five warranty claims filed in the US since the initial report, Toyota said the recall decision came as it "concluded that voltage reduction due to deterioration of the hybrid battery over time could contribute to further incidents".
The solution is a trip to the dealer to get the updated HEV ECU software, installed for free. Toyota says it expects to send notification letters beginning February 27. Until then, owners can contact Toyota at 800-331-4331 and refer to internal recall number 23TA01. Or they can contact the National Highway Traffic Safety Administration at 888-327-4236 (TTY 1-800-424-9153), or visit www.nhtsa.gov and see campaign number 23V041000.