Toyota is recalling 16,679 units of the 2021 RAV4 Prime plug-in hybrid over a software logic problem that can potentially occur in narrow circumstances. The Hybrid Vehicle Control ECU (HEV ECU) contains programming managing parameters for the high-voltage hybrid battery that ensures safe running and protects the battery. It’s been found that when a driver’s been in EV Mode in cold temperatures and pushes the throttle pedal quickly, the battery voltage can plummet below a safety threshold. If that happens, the vehicle will display a warning message before shutting down the hybrid system, which shuts down the vehicle. If this occurs at higher speeds, the occupants face increased risk of a crash.
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 every one of the recalled vehicles has the software in question, not all of the vehicles were sold in the U.S. Also, no other Toyota or Lexus product uses the same HEV ECUs. Only five warranty claims have been filed in the U.S. since the initial report, Toyota saying the recall decision came when it “concluded that voltage reduction due to hybrid battery deterioration over time could contribute to further occurrences.”
The fix is a trip to the dealer for updated HEV ECU software, installed free of charge. 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 get in touch with the National Highway Traffic Safety Administration at 888-327-4236 (TTY 1-800-424-9153), or go to www.nhtsa.gov, and refer to campaign number 23V041000.