Recall 15V623 covers 4 Thomas Built Buses Saf-T-Liner C2 buses for an ECM short circuit. Free ECM replacement at a franchised Thomas Built Buses dealer.
Thomas Built Buses is recalling 4 2016 Saf-T-Liner C2 school buses under recall 15V623 because the Cummins engine control module can short circuit, blow a fuse, and stall the engine without warning. An unexpected stall increases crash risk, and Thomas Built Buses dealers will complete the recall repair free of charge.
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What's wrong?
The engine control module, or ECM, on the 2016 Thomas Built Buses Saf-T-Liner C2 is the computer that manages engine operation. On buses equipped with the Cummins ISB 6.7 engine, it reads engine signals and sends commands that keep fuel, ignition, and other engine functions coordinated while the bus is running.
On included buses, the ECM can develop an internal electrical short. That short can overload the ECM power circuit and blow its fuse. Once that happens, the engine loses the electronic control it needs to keep running, so the bus stalls.
There is no warning sign before failure. The engine stalls without warning, and if the fuse blows, the engine cannot be restarted until the ECM and fuse are replaced.
Who's affected?
The same bus group appears under electrical system and engine because the defect involves more than one vehicle system.
| 2016 Thomas Built Buses Saf-T-Liner C2 | electrical system |
|---|---|
| 2016 Thomas Built Buses Saf-T-Liner C2 | Engine |
| Units affected | 4 |
| Field incidents | NHTSA has logged no 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 ECM electrical short can blow the ECM supply fuse, stall the engine without warning, and increase the risk of a crash. If the bus stalls, it will not restart until the ECM and fuse are replaced. Schedule the repair soon. Repair is free at any franchised Thomas Built Buses dealer.
What should I do?
- Check your VIN to confirm your 2016 Thomas Built Buses Saf-T-Liner C2 is included in this recall.
- Contact a franchised Thomas Built Buses dealer to schedule the free ECM replacement that fixes the short-circuit risk behind the no-warning engine stall.
- Bring the recall notice if Thomas Built Buses mailed one. If not, reference recall number 15V623 when you call.
- Drive cautiously until the repair is complete. An engine stall without warning increases crash risk.
What happens at the repair
At the dealer, a Thomas Built Buses technician replaces the engine control module that can short circuit and stall the engine without warning. The replacement parts and labor are free under recall 15V623. If you've already paid out of pocket for an ECM repair tied to this issue, Thomas Built Buses' standard reimbursement plan covers documented expenses. Bring repair paperwork and receipts to the service desk when you arrive.
| Reimbursement | Reimbursement available |
|---|
Timeline
| October 5, 2015 | NHTSA published the recall |
|---|---|
| October 22, 2015 | Owner notification mailed |
| November 28, 2015 | Dealer notification began |
| November 28, 2015 | Dealer notification ended |
| November 28, 2015 | Interim owner notification (was planned for this date) |
Frequently asked questions
What is recall 15V623?
Recall 15V623 covers 4 2016 Thomas Built Buses Saf-T-Liner C2 school buses with a Cummins ISB6.7 engine control module that can short circuit, blow a fuse, and stall the engine without warning. Thomas Built Buses dealers will replace the ECM for free.
What should I do if my 2016 Thomas Built Buses Saf-T-Liner C2 is on this recall?
Check your VIN to confirm your specific bus is included in recall 15V623. If it is, contact a franchised Thomas Built Buses dealer to schedule the ECM replacement. Reference recall number 15V623 when you call. The repair is free.
Is the recall repair free?
Yes. Federal recall law requires manufacturers to repair safety defects at no cost, and Thomas Built Buses dealers will replace the engine control module free of charge. Parts and labor are covered under recall 15V623.
What is the safety risk?
The safety risk is an engine stall without warning. If the ECM short circuits and blows a fuse, the engine can stall while the bus is moving, increasing crash risk. The free dealer repair replaces the ECM.
What warning signs should I watch for?
There is no warning sign before the stall described in recall 15V623. The filing says the ECM can short circuit, blow a fuse, and cause the engine to stall without warning. Confirm the VIN and schedule the free ECM replacement with a Thomas Built Buses dealer.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/15V623000 |
|---|---|
| Thomas Built Buses customer service | 1-800-745-8000 |
| NHTSA recall # | 15V623 |
| NHTSA recall # (full) | 15V623000 |
Source documents
This article is generated from NHTSA's primary recall filings and reviewed against the source on May 31, 2026. RecallNotify does not paraphrase NHTSA's consequence language; that text is reproduced as written above. Editorial standards →