Recall 18V670 covers 2 2017 Nova Bus Lfs and Lfs Artic buses for pressure-switch failure. Repair is free through Allison service centers.
Nova Bus is recalling 2 2017 Lfs and Lfs Artic transit buses under recall 18V670 because pressure switches in certain Allison hybrid drive units can fail and cause loss of drive. A loss of drive can disable the bus unexpectedly and increase crash risk, and Nova Bus dealers will complete the repair free of charge.
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What's wrong?
The automatic transmission hybrid drive unit on the 2017 Nova Bus Lfs and Lfs Artic transit buses helps turn engine and electric power into motion at the wheels. Inside that drive unit, pressure switches confirm that the transmission has the pressure it needs to operate and keep the bus moving.
On the affected buses, the pressure switch assembly was built with plastic molding that was outside specification. That plastic can fracture inside the switch. When the switch fails, the hybrid drive unit can lose the signal it needs to keep drive power engaged, resulting in a loss of drive.
There is no warning sign before failure. This recall does not list a warning light, noise, vibration, or shift symptom before the pressure switch fails.
Who's affected?
Covers the Lfs and Lfs Artic, with the same automatic-transmission component listed for each bus.
| 2017 Nova Bus Lfs | automatic transmission |
|---|---|
| 2017 Nova Bus Lfs Artic | automatic transmission |
| Units affected | 2 |
| 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?
A loss of drive can disable the bus without warning, which increases the risk of a crash. There is no warning sign before failure, so remove the vehicle from service if it loses propulsion and arrange the recall repair. Repair is free at any franchised Nova Bus dealer.
What should I do?
- Check your VIN to confirm your 2017 Nova Bus Lfs or Lfs Artic is included in this recall.
- Contact Nova Bus customer service at 1-800-350-6682 to confirm the service path for your bus.
- Schedule the free C1 and C2 pressure-switch replacement with an Allison Transmission service center; this repair addresses the hybrid drive-unit switch failure that can cause loss of drive.
- Bring any recall notice and reference recall number 18V670 and Nova Bus recall CR4435 when you schedule service.
- Drive cautiously until the repair is complete and remove the bus from service if drive power drops.
What happens at the repair
At an Allison Transmission service center, the C1 and C2 pressure switches on the hybrid drive unit are replaced. The replacement parts and labor are free under the recall. If you already paid for this repair before the owner notice, Nova Bus handles reimbursement case by case under its standard pre-notice reimbursement plan. Bring repair paperwork and ask Nova customer service or the service center how to submit the claim.
| Reimbursement | Reimbursement available |
|---|
Timeline
| September 26, 2018 | NHTSA published the recall |
|---|---|
| October 5, 2018 | Owner notification mailed |
| November 20, 2018 | Interim owner notification (was planned for this date) |
Frequently asked questions
What is recall 18V670?
Recall 18V670 covers 2 2017 Nova Bus Lfs and Lfs Artic transit buses with Allison hybrid drive units. The C1 and C2 pressure switches can fail, causing a loss of drive. Allison Transmission service centers replace the switches for free.
What should I do if my 2017 Nova Bus Lfs or Lfs Artic is on this recall?
Check your VIN to confirm whether your bus is included in recall 18V670. If it is, contact Nova Bus customer service at 1-800-350-6682 or an Allison Transmission service center to arrange the free C1 and C2 pressure switch replacement. Reference Nova Bus recall CR4435.
Is the recall repair free?
Yes. Federal recall law requires the defect repair at no cost, and Nova Bus says Allison Transmission service centers will replace the C1 and C2 pressure switches free of charge under recall 18V670.
What is the safety risk?
The safety risk is an unexpected loss of drive. If a pressure switch fails, the transit bus can lose propulsion and become disabled before the driver chooses to stop. That raises crash risk. If your VIN is included, arrange the free switch replacement before returning the bus to regular service.
When did the recall repair become available?
The recall repair began October 5, 2018. Because that date has passed, affected owners can contact Nova Bus customer service or an Allison Transmission service center now to arrange the free C1 and C2 pressure switch replacement.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/18V670000 |
|---|---|
| Nova Bus customer service | 1-800-350-6682 |
| NHTSA recall # | 18V670 |
| NHTSA recall # (full) | 18V670000 |
Source documents
-
Download Recall Investigation Document (PDF) (PDF) - Download Owner Notification Letter (PDF)
- Download Recall Report (PDF)
- Download Quarterly Report (PDF)
- Download Recall Acknowledgement (PDF)
This article is generated from NHTSA's primary recall filings and reviewed against the source on May 25, 2026. RecallNotify does not paraphrase NHTSA's consequence language; that text is reproduced as written above. Editorial standards →