Toyota Says Future-EV Testing Led It to an 8,521-Vehicle C-HR Recall

Toyota says development testing on an unnamed future battery-electric vehicle led it to discover the software issue behind a U.S. safety recall covering 8,521 potentially involved 2026 C-HRs. In the Part 573 report Toyota submitted to the National Highway Traffic Safety Administration, the company says an incorrect software parameter found during future-BEV testing prompted it to review battery-electric models already on the market, where it identified an incorrect battery-charging-control parameter in the C-HR.¹

NHTSA campaign 26V570, which Toyota identifies as campaign 26TA17, lists 8,521 potentially involved vehicles. Toyota's filing gives an affected production range of Feb. 6 through July 10, 2026, while noting that not every vehicle built in that range was sold in the United States.¹²

When Toyota says the shutdown can happen

Toyota's filing says the C-HR's battery-control software is supposed to limit charging to protect the drive battery, but the programming can allow the battery to become overcharged under certain conditions. Toyota says the condition is particularly associated with a high battery state of charge and prolonged regenerative braking, such as coasting a long distance downhill, especially in low temperatures.¹

If the condition occurs, Toyota says warning lights illuminate and a warning buzzer sounds as the electric drive system shuts down. The recall filing says the resulting loss of motive power can increase crash risk when the vehicle is traveling at higher speed.¹ NHTSA's Sept. 9 acknowledgement similarly describes the issue as one that can result in a loss of drive power.²

The Part 573 lists the estimated percentage of vehicles with the defect as 100%, but that figure should not be read as a 100% shutdown rate. Toyota explains that all vehicles in the recall population contain the software programming at issue; whether an individual C-HR actually reaches the overcharge and shutdown condition depends on the driving conditions described in the filing.¹

The problem surfaced during development work

Toyota says it first identified an incorrect BEV-ECU software parameter in late April while development-testing a future battery-electric model. The filing does not identify that future vehicle. Toyota says the finding prompted a review of other BEVs already in the market, which led it to the C-HR's battery-charging-control parameter.¹

The company says it then carried out vehicle-bench and simulation testing in July, varying temperature and vehicle speed while testing high-state-of-charge regenerative braking. Toyota says that work reproduced a condition in which overcharging could cause the electric drive system to shut down, particularly at low temperatures. Toyota says it decided to conduct a voluntary safety recall on Aug. 28.¹

Toyota's filing also says its record review found no related Toyota Field Technical Reports and no warranty claims from U.S. sources as of Aug. 26.¹ That statement is limited to those two record categories and that date; the filing does not establish the broader claim that there were no complaints, crashes, injuries or other owner incidents.

The remedy is a dealer software update

The remedy is a no-cost update to the C-HR's BEV-ECU software performed by a Toyota dealer.¹² The current Part 573 form has neither the Do Not Drive nor Park Outside consumer-advisory box selected, which does not negate the loss-of-motive-power risk described elsewhere in the same recall filing.¹

Toyota's Part 573 lists planned remedy-owner notification from Oct. 18 through Nov. 1, 2026. NHTSA's acknowledgement says owner notification letters are expected to begin mailing Oct. 18.¹²

Sources

Footnotes

1. Part 573 Safety Recall Report 26V570 — Toyota Motor Engineering & Manufacturing submission published by the National Highway Traffic Safety Administration, Sept. 2, 2026. https://static.nhtsa.gov/odi/rcl/2026/RCLRPT-26V570-8322.pdf Establishes the 8,521-vehicle campaign population, production range, software/overcharge condition, Toyota's development and testing chronology, the bounded Aug. 26 record-review statement, dealer remedy, advisory selections and planned owner-notification schedule. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹

2. NHTSA Recall Acknowledgement — 26V570 — National Highway Traffic Safety Administration, Office of Defects Investigation, Recall Management Division, Sept. 9, 2026. https://static.nhtsa.gov/odi/rcl/2026/RCAK-26V570-3899.pdf Confirms campaign 26V570 / Toyota 26TA17, 8,521 potentially affected vehicles, the loss-of-drive-power description, dealer BEV-ECU software remedy and expected Oct. 18 owner-letter timing. ↩ ↩² ↩³ ↩⁴