Recall 22V439 affects 258 2019-2023 Thomas Built Buses Saf-T-Liner C2 and S2G vehicles for unexpected engine shutdown. Free repair once available.
Thomas Built Buses is recalling 258 2019-2023 Saf-T-Liner C2 and S2G vehicles with 8.8L LPG engines because the engine control module can set a fault code that shuts the engine down unexpectedly. An unexpected shutdown can increase crash risk, and the dealer repair will be free once Thomas Built Buses opens the remedy.
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What's wrong?
The engine control module, or ECM, is the computer that manages how the 8.8L LPG engine runs in affected 2019-2023 Thomas Built Buses Saf-T-Liner C2 and S2G vehicles. It reads sensor data, controls fuel and ignition commands, and keeps the engine operating within required emissions settings. When it sets the wrong fault response, the engine no longer gets the control commands it needs to keep running.
On these vehicles, the ECM can set a fault code tied to the propane engine system. When that happens, the engine can shut down unexpectedly, including while the vehicle is in motion. DTNA traced the concern through reports of stalling and related error codes, then tested ECM replacement as the repair path for the fault-code condition.
There is no warning sign before failure. The filing says the engine can stall suddenly without any warning, so an owner or fleet driver should not expect a dashboard message, noise, or drivability change before the shutdown.
Who's affected?
Covers the Saf-T-Liner C2 bus and S2G chassis across the 2019, 2020, 2021, 2022, and 2023 model years, all tied to the same engine control module.
| 2023 Thomas Built Buses Saf-T-Liner C2 | Engine control module (ecu/ecm) |
|---|---|
| 2020 Fccc S2G | Engine control module (ecu/ecm) |
| 2019 Fccc S2G | Engine control module (ecu/ecm) |
| 2021 Fccc S2G | Engine control module (ecu/ecm) |
| 2022 Fccc S2G | Engine control module (ecu/ecm) |
| Units affected | 258 |
| Field incidents | NHTSA has logged no field incidents to date. |
The year and model narrow the scope, but the VIN decides. Check your VIN to confirm whether your specific vehicle is included.
What's the safety risk?
An unexpected engine shut down can raise the risk of a crash. There is no warning before it happens, so treat any sudden loss of power as a reason to stop in a safe place and contact the dealer. Repair will be free at any franchised Thomas Built Buses dealer once available.
What should I do?
- Check your VIN to confirm your 2019-2023 Thomas Built Buses Saf-T-Liner C2 or S2G is included in this recall.
- Contact Thomas Built Buses customer service before scheduling because the remedy status is not marked available.
- Ask when the free ECM software update opens; the update fixes the fault-code issue that can shut the engine down unexpectedly.
- Reference recall number 22V439 and DTNA recall FL942 when you call.
- Avoid unnecessary driving until Thomas Built Buses confirms the repair path for your VIN.
What happens at the repair
At the dealer, a Thomas Built Buses technician will update the engine control module software once the final remedy is available. The software update is meant to address the fault code condition linked to unexpected engine shutdown. The dealer repair will be free once it opens, with parts and labor covered under the recall. Owner letters have already been mailed, and authorized Daimler Trucks North America service facilities are expected to perform the work.
Timeline
| June 20, 2022 | NHTSA published the recall |
|---|---|
| August 19, 2022 | Dealer notification began |
| August 19, 2022 | Dealer notification ended |
| August 19, 2022 | Interim owner notification (was planned for this date) |
| October 28, 2022 | Owner notification mailed |
Frequently asked questions
What is recall 22V439?
Recall 22V439 covers 258 2019-2023 Thomas Built Buses Saf-T-Liner C2 and S2G vehicles with 8.8L LPG engines. The engine control module can set a fault code that shuts the engine down unexpectedly, increasing crash risk. Dealers will update the ECM software for free.
What should I do if my 2019-2023 Thomas Built Buses Saf-T-Liner C2 or S2G is on this recall?
Check your VIN to confirm your specific vehicle is included in recall 22V439. If it is, contact a franchised Thomas Built Buses dealer and ask about the ECM software update. Reference recall number 22V439 and DTNA recall FL942 when you call.
Is the recall repair free?
Yes. Federal recall law requires the manufacturer to repair the defect at no cost, and DTNA says dealers will update the ECM software free of charge. Parts and labor are covered at a franchised Thomas Built Buses dealer.
What is the safety risk?
The safety risk is an unexpected engine shutdown while the vehicle is in use. If the engine shuts down, the driver can lose power unexpectedly, increasing crash risk. The repair path is the dealer ECM software update.
When were owner letters mailed for recall 22V439?
Owner notification letters were mailed October 28, 2022. If you bought the vehicle used or never received a letter, check your VIN to confirm whether your specific Saf-T-Liner C2 or S2G is included before calling the dealer.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/22V439000 |
|---|---|
| Thomas Built Buses customer service | 1-800-547-0712 |
| NHTSA recall # | 22V439 |
| NHTSA recall # (full) | 22V439000 |
Source documents
-
Download Recall Document (PDF) (PDF) - Download Quarterly Report (PDF)
- Download Owner Notification Letter (PDF)
- Download Misc. Document (PDF)
- Download Recall Report (PDF)
- Download Owner Notice (PDF)
- Download Recall Document (PDF) (PDF)
- Download Recall Acknowledgement (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 →