GreenPower Motor Company told NHTSA that the interlock meant to hold a lift-equipped bus in place was never fully written into the vehicle’s operating software. The affected fleet is small, 94 buses in all, but the gap sits in the one system that protects a passenger who is on the wheelchair platform at the curb.
NHTSA received the filing on September 30, 2026, as campaign 26V629000. Its summary says a control module interlock software error may let the bus move while the wheelchair lift is deployed, and its consequence line says that movement during lift use raises the risk of injury.
Interlock logic that never made it into the software
The longer account sits in GreenPower’s defect report to NHTSA, which gives the cause as interlock logic for the vehicle’s operational software that was not properly added. Three failure paths are laid out. If an operator does not set the park brake, the bus could roll on an incline. If the park brake is released while the lift is out, the bus could roll or be shifted into drive or reverse and driven. And during manual lift deployment, the motion of the lift could interrupt power and let an unbraked bus roll.
The trigger for the review was a single piece of video. In February 2026, according to the report, NHTSA forwarded footage of a Nano-Beast school bus, a related GreenPower model, in which operators had not followed the proper procedure and the lift was only partly deployed, possibly because of a relaxed or failed control valve. The vehicle stopped moving once the lift was stowed by hand.
GreenPower then spent March through July running a failure mode and effects analysis and an interlock assessment. Its conclusion, as the report puts it, was that the interlock standard had not been written with non-powered manual operation in mind. The company decided to change the system so that raising or lowering the lift triggers the hill-hold function.
Which EV Stars are in the 94
NHTSA’s record names two products: the 2018 through 2024 EV Star and the 2020 through 2023 EV Star Mobility Plus. The report splits the population into 87 EV Stars and 7 Mobility Plus buses, with production dates running from January 1, 2018 through September 29, 2026. Two of the units were final-stage built by Weichai Yangzhou Yaxing Commercial Vehicle Co. Ltd.
The EV Star is a roughly 25-foot battery-electric minibus. GreenPower’s own delivery notice for the Sacramento Regional Transit District describes three of them equipped with curbside wheelchair lifts, ADA features and two ADA positions, for an on-demand shuttle booked through a phone app. That is the kind of duty cycle in play here: short stops, frequent boardings, and a lift cycled many times a shift.
One discrepancy sits inside the paperwork. The chronology refers to corrective action for about 102 vehicles, including 2021 Nano-Beast models, while the population section totals 94. A separate filing, 26V643000, covers eight Nano-Beast school buses, which accounts for the gap on the face of the data, though the report does not say so in terms. The 94 figure used here is the one NHTSA carries for this campaign.
The practical stakes are easiest to see at a curb. A lift platform carrying a rider in a powered chair sits at the side of the bus, often with the driver at the controls and a ramp or lift cycle in progress. If the drivetrain is not locked out at that moment, any unintended roll or shift into gear moves the vehicle away from the person on the platform. GreenPower’s fix targets that exact moment by tying lift activation to the hill-hold function and the park-brake interlock, so the controller refuses to treat the bus as free to move while the lift is out.
Park-brake fix and the October mailing
The NHTSA campaign record sets out the remedy: a software update to the control module so that lift operation is allowed only while the park brake interlock is engaged. The NHTSA record says dealers will perform the update at no cost, and it points owners to GreenPower customer service at 1-909-346-1090 under recall number GP2604002.
The report attaches a “Do Not Drive Park Outside” advisory and plans owner notices between October 12 and October 26, 2026, by mail or email, with the caveat that dates may change. The recall is phased, and the document says no dealer notification or interim owner letter is planned. The NHTSA record itself gives October 12, 2026 as the expected mailing date.
The report says GreenPower has received no further reports since the February video, and it describes no injuries, deaths or crashes. Testing and programming of the update were still being finalized when it was filed. Owners can check a vehicle identification number at NHTSA’s recall lookup, and the full row is also visible in the agency’s open recall data feed.
What remains unresolved is timing: the update was described as in final testing, with deployment slated for early to mid-October, and operators of the 94 buses have no published release date for the software itself.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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