Recall 20V457 affects 34 2016 Nova Bus Lfs Artic and Lfs buses for transmission pressure-switch failure. Repair is free at a franchised Nova Bus dealer.
Nova Bus is recalling 34 2016 Lfs Artic and Lfs buses under recall 20V457 because pressure switches in certain Allison Transmission drive units can fail and cause a loss of drive. That loss of drive can disable the bus unexpectedly, raise crash risk, and add injury risk during passenger transfers; Nova Bus dealers will complete the repair free of charge.
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What's wrong?
The C1/C2 pressure switch in the Allison H 40/50 EP Drive Unit helps the transmission control hydraulic pressure inside the drive system. On 2016 Nova Bus Lfs and Lfs Artic buses, that switch is part of the automatic transmission equipment that lets the bus move when the driver requests power.
The problem is inside the pressure switch assembly. The plastic molding in the recalled switches was made with 100% recycled regrind material instead of the virgin resin required by Allison Transmission's design. That weaker plastic can fracture inside the switch assembly. When the switch fails, the drive unit loses the pressure signal it needs, and the bus can lose drive.
In some circumstances, a malfunction indicator lamp, or MIL, can turn on shortly before the pressure switch fails. That warning light is the sign to report when contacting Nova Bus service or the transit maintenance team.
Who's affected?
Covers the Lfs Artic and Lfs configurations, both tied to the automatic transmission pressure switch.
| 2016 Nova Bus Lfs Artic | automatic transmission |
|---|---|
| 2016 Nova Bus Lfs | automatic transmission |
| Units affected | 34 |
| Field incidents | NHTSA has logged 1 field incident to date. |
A matching 2016 Nova Bus Lfs Artic or Lfs does not guarantee inclusion. Check your VIN to confirm whether your specific bus is included.
What's the safety risk?
Loss of drive can disable the bus unexpectedly, increasing crash risk. If the malfunction indicator lamp turns on, treat it as a warning sign and schedule service before returning the bus to passenger use. Offloading passengers for transfer after a failure also raises injury risk. Repair is free at any franchised Nova Bus dealer.
What should I do?
- Check your VIN to confirm your 2016 Nova Bus Lfs Artic or Lfs is included in this recall.
- Contact a franchised Nova Bus dealer to schedule the free transmission pressure-switch repair.
- Schedule the C1 and C2 pressure-switch replacement that fixes the transmission switch failure linked to loss of drive.
- Bring the recall notice if Nova Bus mailed one. If not, reference recall number 20V457 and Nova Bus recall CR4943 when you call.
- Plan service before passenger routes, and use a backup bus until the repair is complete.
What happens at the repair
At the dealer, a Nova Bus technician replaces the C1 and C2 pressure switches in the affected Allison Transmission drive unit. The switch replacement and labor are free under recall 20V457. Out-of-pocket repairs before owner notification are handled through the manufacturer's warranty or goodwill coverage, not through a separate reimbursement program. Ask the service desk how that warranty or goodwill coverage applies if you have prior repair paperwork for a related pressure switch failure or loss of drive.
| Reimbursement | Warranty coverage applies |
|---|
Timeline
| August 5, 2020 | NHTSA published the recall |
|---|---|
| September 15, 2020 | Owner notification mailed |
| September 18, 2020 | Dealer notification began |
| September 18, 2020 | Dealer notification ended |
| September 18, 2020 | Interim owner notification (was planned for this date) |
Frequently asked questions
What is recall 20V457?
Recall 20V457 covers 34 2016 Nova Bus Lfs Artic and Lfs buses equipped with specific Allison Transmission drive units. The C1 and C2 pressure switches can fail, resulting in a loss of drive. Allison Transmissions will replace the pressure switches free of charge.
What should I do if my 2016 Nova Bus Lfs Artic or Lfs is on this recall?
Check your VIN to confirm your specific bus is included in recall 20V457. If it is, contact Nova Bus customer service at 1-800-350-6682 and reference recall CR4943. Allison Transmissions will replace the C1 and C2 pressure switches for free.
Is the recall repair free?
Yes. Federal recall law requires the manufacturer to repair the defect at no cost, and Nova Bus says Allison Transmissions will replace the C1 and C2 pressure switches free of charge for buses included in recall 20V457.
What is the safety risk?
A loss of drive can disable the bus unexpectedly and increase crash risk. Nova Bus also warns that moving passengers to another bus after a roadside disablement can increase injury risk. The repair path is to have Allison Transmissions replace the affected pressure switches for free.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/20V457000 |
|---|---|
| Nova Bus customer service | 1-800-350-6682 |
| NHTSA recall # | 20V457 |
| NHTSA recall # (full) | 20V457000 |
Source documents
-
Download Recall Document (PDF) (PDF) - Download Quarterly Report (PDF)
- Download Recall Document (PDF) (PDF)
- Download Recall Investigation Document (PDF) (PDF)
- Download Owner Notification Letter (PDF)
- Download Recall Report (PDF)
- Download Recall Acknowledgement (PDF)
This article is generated from NHTSA's primary recall filings and reviewed against the source on May 24, 2026. RecallNotify does not paraphrase NHTSA's consequence language; that text is reproduced as written above. Editorial standards →