Recall 24V655 affects 483 2019-2022 Proterra ZX5 and Catalyst transit buses for radiator fan circuit overheating. Repair is free at any franchised Proterra dealer.
Proterra is recalling 483 2019-2022 ZX5 and Catalyst transit buses because vehicle controller software can allow the radiator fan circuit to overheat. Overheated electrical circuits increase the risk of a fire, and Proterra dealers will complete the repair free of charge.
Does this recall apply to your specific vehicle?
The official, free per-VIN recall check is run by NHTSA. Enter your VIN and we'll forward you directly — and add you to a free watchlist so you hear about new recalls for your vehicle.
Check my VIN at NHTSARecallNotify doesn't check your VIN — NHTSA's official tool does. We use your email only to alert you to new recalls.
Watch this vehicle for recalls
Add it to your free watchlist and we will alert you as new federal recalls are posted for your year, make and model. New-recall alerts are rolling out now.
You are on the watchlist.
We will email you as new federal recalls are posted for your vehicle.
What's wrong?
The radiator fan circuit on 2019-2022 Proterra ZX5 and Catalyst transit buses powers the fan that helps move heat out of the cooling system. The vehicle controller software commands that fan and sends electrical load through a pass-through connector in the harness. That connector is supposed to carry the circuit load without overheating.
On these buses, the circuit was designed too close to its maximum current limit once heat, vibration, and other operating stress are counted. Poor crimping in the harness can add resistance, which raises heat at the connector. If the controller allows the fan to run at a high enough load for long enough, the connector pins can discolor or suffer thermal damage.
Operators can see warning lights on the dash when the fan is commanded on but feedback shows it is off. Phoenix diagnostic tools or telemetry can show related diagnostic codes, which tell the operator to remove the bus from service and inspect the circuit.
Who's affected?
Spans the ZX5 and Catalyst bus lines across the 2019-2022 model years, with the electrical system listed for each model year.
| 2021 Proterra ZX5 | electrical system |
|---|---|
| 2019 Proterra Catalyst | electrical system |
| 2020 Proterra Catalyst | electrical system |
| 2020 Proterra ZX5 | electrical system |
| 2021 Proterra Catalyst | electrical system |
| 2022 Proterra ZX5 | electrical system |
| Units affected | 483 |
| Field incidents | NHTSA has logged 20 field incidents to date. |
A matching year and model does not guarantee inclusion. Check your VIN to confirm whether your specific bus is included.
What's the safety risk?
An overheated electrical circuit increases the risk of fire. If a fan warning light appears while the fan is commanded on, remove the vehicle from service and have the circuit inspected before further operation. Repair is free at any franchised Proterra dealer.
What should I do?
- Check your VIN to confirm your 2019-2022 Proterra ZX5 or Catalyst is included in this recall.
- Contact a franchised Proterra dealer to schedule the free vehicle software update.
- Ask for the software update that prevents the radiator-fan electrical circuit from overheating.
- Bring the recall notice if you have it. If not, reference recall number 24V655 when you call.
- Ask the dealer about operating limits until the update is complete, because overheating electrical circuits increase the risk of a fire.
What happens at the repair
At the dealer, a Proterra technician updates the vehicle controller software on the recalled 2019-2022 ZX5 and Catalyst buses. The update is meant to correct the software condition that allows the radiator fan circuit to overheat. The recall repair is free, and parts and labor are covered. Ask the dealer to confirm that campaign 24V655 is open for your VIN before arranging service.
Timeline
| September 6, 2024 | NHTSA published the recall |
|---|---|
| September 23, 2024 | Dealer notification began |
| September 23, 2024 | Interim owner notification (was planned for this date) |
| September 30, 2024 | Dealer notification ended |
| October 15, 2024 | Owner notification mailed |
Frequently asked questions
What is recall 24V655?
Recall 24V655 covers 483 2019-2022 Proterra ZX5 and Catalyst transit buses. The vehicle controller software can let the radiator fan circuit overheat, which increases fire risk. Dealers will update the vehicle software for free.
What should I do if my 2019-2022 Proterra ZX5 or Catalyst is on this recall?
Check your VIN to confirm your specific bus is included in recall 24V655. If it is, contact a franchised Proterra dealer to schedule the vehicle software update. Reference recall number 24V655 when you call. The repair is free.
Is the recall repair free?
Yes. Federal recall law requires manufacturers to fix safety recalls at no cost, and the recall remedy says dealers will update the vehicle software free of charge at a franchised dealer.
What is the safety risk?
The safety risk is fire. Recall 24V655 says the vehicle controller software can allow the radiator fan electrical circuit to overheat, and overheating electrical circuits increase fire risk. Confirm the VIN and arrange the free software update if the bus is included.
When were owners notified about recall 24V655?
Owner notification letters were mailed October 15, 2024. If you own or operate a 2019-2022 Proterra ZX5 or Catalyst bus and never received a letter, check your VIN and contact a franchised Proterra dealer about the free software update.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/24V655000 |
|---|---|
| Proterra customer service | 1-909-987-0815 |
| NHTSA recall # | 24V655 |
| NHTSA recall # (full) | 24V655000 |
Source documents
-
Download Quarterly Report (PDF) - Download Recall Investigation Document (PDF) (PDF)
- Download Owner Notification Letter (PDF)
- Download Recall Acknowledgement (PDF)
- Download Recall Report (PDF)
This article is generated from NHTSA's primary recall filings and reviewed against the source on May 20, 2026. RecallNotify does not paraphrase NHTSA's consequence language; that text is reproduced as written above. Editorial standards →