Verdict · NHTSA data
Limited data — recalls on file
NHTSA has just 0 complaints on file for the 2021 Proterra Zx5 — too few to judge reliability from owner reports alone — but 6 recall campaigns apply to this year, so any used example should have its VIN checked for completed recall work.
0
NHTSA complaints
6
Recalls
0
Investigations
0
Crash-involved
0
Fires reported
0
Injuries
0
Deaths
—
NCAP overall
6 NHTSA recall campaigns on file. Recall repairs are free at franchised dealers.
Defect
Phoenix Motorcars (Phoenix) is recalling certain 2019-2021 800V Catalyst and 2020-2022 ZX5 transit buses. The vehicle controller software may allow the electrical circuit for the radiator fan to overheat.
Consequence
Electrical circuits that overheat increase the risk of a fire.
Remedy
Dealers will update the vehicle software, free of charge. Owner notification letters were mailed October 15, 2024. Owners may contact Phoenix customer service at 1-909-987-0815.
Defect
Proterra Operating Company, Inc. (Proterra) is recalling certain 2019-2022 40' and 35' Catalyst 800V transit buses equipped with ProDrive 1.0, and 40' and 35' ZX5 800V transit buses equipped with ProDrive 1.0. A transistor inside the inverter may overheat and fail, which can result in a loss of power steering and drive power.
Consequence
A loss of power steering and/or drive power increases the risk of a crash.
Remedy
Dealers will replace the inverter, free of charge. Owner notification letters were mailed December 16, 2023. Owners may contact Proterra customer service at 1-864-438-0000.
Defect
Proterra Operating Company, Inc. (Proterra) is recalling certain 2020-2022 35" Catalyst, 35" ZX5, and 40" ZX5 vehicles. The windshield wiper motors may operate intermittently or may fail to operate. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 104, "Windshield Wiping and Washing Systems."
Consequence
Inoperative windshield wipers can reduce visibility in certain driving conditions, increasing the risk of a crash.
Remedy
Dealers will replace the wiper motors, free of charge. Owner notification letters were mailed April 3, 2023. Owners may contact Proterra customer service at 1-864-438-0000.
Defect
Proterra Operating Company, Inc. (Proterra) is recalling certain 2020-2021 Catalyst and 2019-2022 ZX5 transit buses. Back pressure in the shared air exhaust for the pneumatic ride height system and parking brake control valve may engage the parking brake while the vehicle is in motion.
Consequence
Unintentional engagement of the parking brake increases the risk of a crash.
Remedy
Proterra will install a redesigned air circuit, free of charge. Owner notification letters were mailed on December 21, 2022. Owners may contact Proterra's customer service at 1-864-438-0000.
Defect
Proterra, Inc. (Proterra) is recalling certain 2017-2019 35 foot Catalyst E2, 2017-2019 40 foot E2, 2020-2021 35 foot RR, 2019-2020 40 foot RR, 2019-2022 40 foot ZX5, and 2020-2022 35 foot ZX5 buses. The plexus adhesive between the torque limiter plate and the bus body may be insufficient, causing the bolts that secure the steering gearbox to loosen.
Consequence
A loose steering gearbox can cause a loss of steering control, increasing the risk of a crash.
Remedy
Dealers will install a mechanical fastener and new bolts on the steering gearbox, and install a new torque plate, as necessary, free of charge. Owner notification letters were mailed October 7, 2022. Owners may contact Proterra's customer service at 1-864-438-0000.
Defect
Proterra, Inc. (Proterra) is recalling certain 2020-2021 40' ZX5 vehicles. These vehicles have a front fender flare which may cause mud, dirt, debris, rain and snow to splash onto the driver's side window and mirror.
Consequence
Driver visibility may become impeded, increasing the risk of a crash.
Remedy
Proterra will notify owners, and dealers will install a retrofit fender flare, free of charge. The recall began February 9, 2021. Owners may contact Proterra customer service 1-864-438-0000. Proterra's number for this recall is SC-21-13.
The record is thin — 0 NHTSA complaints — so owner-report data can't strongly confirm reliability either way, though 6 recalls should be verified as completed.
Yes — NHTSA lists 6 recall campaigns affecting the 2021 Proterra Zx5. Recall repairs are free at franchised dealers; check the VIN at nhtsa.gov/recalls to confirm the work was done.
Based on NHTSA ODI data through June 2026. Complaints are consumer-reported and unverified. Updated July 5, 2026.
Compiled by Sharon Ben-Moshe, Founder.