Powering the Toyota Prius Battery
Some 2016-2019 Toyota Prius vehicles equipped with a NiMH HV battery may exhibit one or both the following conditions after repeated driving on long downhill slopes or while driving in high ambient temperatures, then turned off for approximately one to two hours and restarted:
- When accelerating from a stop or from extremely low speeds, the vehicle may have a reduction of power;
- The HV battery monitor on the multi-information display continually shows one bar, indicating that the battery state of charge is at its lowest level.
The Hybrid control computer (HV ECU) logic has been modified to reduce the possibility of these conditions. Confirm that the vehicle has a NiMH battery by inspecting the 5th digit or character of the VIN. If the fifth character is a “B” or a “9”, check for an authorized modifications label to see if the HV ECU calibration has been updated. If not already calibrated, flash reprogram the HV ECU with the latest calibration.
About the Author
Information courtesy of Mitchell 1
Information for Technical Service Bulletins comes from ProDemand, Mitchell 1's auto repair information software for domestic and import vehicles. Headquartered in San Diego, Mitchell 1 has provided quality repair information solutions to the automotive industry since 1918.
Mike Mavrigian
Motor Age Editor
Mike Mavrigian has written thousands of automotive technical magazine articles involving a variety of specialties, from engine building to wheel alignment, and has authored more than a dozen books that crisscross the automotive spectrum. Mike operates Birchwood Automotive, an Ohio shop that builds custom engines and performs vintage vehicle restorations. The shop also features a professional photo studio to document projects and to create images for articles and books.