Toyota Motor Engineering & Manufacturing is recalling 20,991 model-year 2026 battery electric vehicles in the United States after identifying a software defect in the battery electronic control unit (ECU) that could cause the electric drive system to shut down while driving.
The voluntary safety campaign, filed under National Highway Traffic Safety Administration (NHTSA) Recall No. 26V393, affects the Toyota bZ, Lexus RZ and Subaru Solterra. Toyota estimates that all recalled vehicles contain the affected battery ECU software.
Battery ECU Software Issue
According to Toyota, the battery ECU contains two integrated circuits that share part of the same memory address.
Under certain operating conditions, the monitoring integrated circuit can repeatedly overwrite data written by the battery control integrated circuit. If this occurs repeatedly, the ECU may fail an operational memory check.
Toyota said the issue is more likely when CPU workload increases, such as when the high-voltage battery is at a low state of charge.
If multiple memory checks fail, the vehicle displays an “EV System Malfunction” warning, illuminates several warning indicators and shuts down the electric drive system.
While power steering and power-assisted braking remain functional, the loss of propulsion increases the risk of a crash. Toyota also noted that some driver assistance systems, including Pre-Collision System (PCS) and Vehicle Stability Control (VSC), could become unavailable.
The affected battery ECU is supplied by Denso Corporation.
Vehicles Included in the Recall
The recall covers three battery electric vehicle models:
- 2026 Toyota bZ: 11,495 vehicles
- 2026 Lexus RZ: 4,739 vehicles
- 2026 Subaru Solterra: 4,757 vehicles
The affected vehicles were produced between April 2025 and April 2026, depending on the model.
Toyota said not every vehicle manufactured during the production period is affected, as only vehicles equipped with the specific battery ECU software are included in the recall.
Investigation and Remedy
Toyota first identified the software behavior during development testing of a new plug-in hybrid vehicle.
Engineers initially concluded the issue would not affect battery electric models because of differences in the monitoring software. However, subsequent analysis of remote diagnostic data from vehicles already in service revealed similar fault patterns.
Additional bench testing confirmed the software defect, leading Toyota to initiate the voluntary recall.
The company said it has received one U.S. warranty claim potentially related to the issue and no field technical reports.
Free Software Update
Toyota, Lexus and Subaru dealerships will update the battery ECU software free of charge.
Owner notification letters are scheduled to begin mailing on August 3, 2026, with the phased remedy campaign expected to continue through August 17, 2026.
Owners who previously paid for repairs related to the condition may be eligible for reimbursement under Toyota’s or Subaru’s reimbursement programs.
Toyota’s internal recall identification numbers are 26LA07 and 26TA11, while Subaru has designated the campaign as WRG26.
