NHTSA safety investigation
NHTSA Investigation RQ25001
Recall Query · Phoenix Motorcars · ELECTRICAL SYSTEM:PROPULSION SYSTEM:TRACTION BATTERY
This investigation is open. That is not a finding that a defect exists.
NHTSA opens an investigation to examine whether a safety defect may exist. An open investigation is not a determination that a defect exists, and many investigations close without a recall. Investigations can, however, lead to one.
What NHTSA is examining
The agency's own description of the inquiry, quoted as published
Remedy Effectiveness of Recall 22V887
In November 2022, Proterra Operating Company, Inc. (Proterra) filed a safety recall (NHTSA recall 22V887) covering nineteen 2017-2019 Proterra Catalyst transit buses to address the potential of liquid accumulation in the 400-volt battery packs, increasing the risk of a fire. On December 16, 2022, Proterra mailed an interim owner notification letter stating that Proterra would physically inspect and analyze each recalled battery pack.In October 2023, Proterra amended their filing to now cover 300 vehicles, with a final remedy plan of updating the battery monitoring software. According to the final remedy documents from Proterra, should liquid be detected within the battery pack, the updated software would illuminate a warning light in the driver's dash display, prevent the batteries from being charged, and reduce the maximum speed of the buses.As of the most recent recall completion rate report, 109 of the 300 buses (36.3%) have received the software update. In August 2023, Proterra declared bankruptcy, with its the three major business areas going to three separate companies.Phoenix Motorcars assumed liability for recall 22V887. On June 5, 2025, a fire occurred at the Southeastern Pennsylvania Transportation Authority (SEPTA) decommissioning lot.Local officials stated that the fire initiated in a battery pack of one of the Proterra buses. The Office of Defects Investigation (ODI) is opening this Recall Query (RQ) to evaluate the remedy effectiveness of recall 22V887 and to further understand the effects of nearly two-thirds of the affected population having not yet received the recall remedy.
An investigation is a separate record from a recall and from a manufacturer communication. A manufacturer campaign to repair a safety defect or a failure to meet a federal safety standard.
Investigation details
Identifiers, dates and outcome as recorded by NHTSA
- Action number
- RQ25001
- Investigation type
- Recall Query (RQ)
- Status
- Open
- Manufacturer
- Phoenix Motorcars
- Component
- ELECTRICAL SYSTEM:PROPULSION SYSTEM:TRACTION BATTERY
- Opened
- Jun 27, 2025
- Closed
- Not recorded
- Associated recall campaign
- None recorded — the inquiry is ongoing
Vehicles named in this investigation
3 model years across 1 model
Being named here means NHTSA included the vehicle in the scope of its inquiry. It is not a statement that these vehicles have a defect.