On 1,376 transit buses and coaches, the hazard lights come on without telling the driver

When a driver switches a bus off with the hazard lights running, the flashing lamps outside keep going while the indicator on the dash can stay dark. That is the fault behind two NHTSA campaigns announced the same week: 26V644000, covering 693 New Flyer transit buses, and 26V645000, covering 683 Motor Coach Industries coaches. Together they reach 1,376 vehicles, and both manufacturers trace the problem to a programming error.

Stay ahead on AI: Join 600,000+ professionals who read The Deep View, the daily newsletter that keeps you up to date with artificial intelligence.

Subscribe to The Deep View →

We may earn a commission if you sign up.

The exposure is specific. Both filings state the risk the same way: operators may not know the exterior hazard lamps are flashing, which may confuse other drivers and increase the risk of a crash. With the master run switch off, the dash indicator that would normally confirm the flashing stays dark. Neither filing reports a crash, an injury or a warranty claim, and the defect was found by a customer who compared the buses to older ones.

A program error behind the master run switch

New Flyer’s Part 573 report for 26V644 says the hazard indicator tell-tale lamps do not flash when the master run switch, the bus’s equivalent of an ignition switch, is off. The cause is given as “a program error” in the hazard warning indicator software, and the standard involved is Federal Motor Vehicle Safety Standard 108 on lamps and reflective devices. The NHTSA campaign record quotes the summary that the instrument panel indicator light may not illuminate when the hazard warning lights are on.

The discovery came from a customer, not a test. In late August 2026, a U.S. customer noticed that the hazard lamps did not behave as they had on previous buses with the master run switch off. New Flyer began checking similar programs in September for an ignition condition, discussed it briefly at a Vehicle Safety Committee meeting on September 16, found documentation of a programming error on September 24, and had the committee agree on September 28 that a noncompliance recall was warranted.

693 New Flyer buses, from fuel cell to battery electric

The New Flyer population is a cross-section of the company’s catalog, which is why the model-year span in the record runs from 2013 to 2027. The filing’s largest block is battery-electric: 269 XE40 buses built between June 2014 and May 2026, 105 XE35 and 24 XE60, for 398 in all. Hybrid-electric buses add 110 XDE40 and 58 XDE60. Fuel-cell XHE60 and XHE40 models account for 62, compressed natural gas XN60 buses for 64, and a single 2026 XD40 with a compression-ignition engine, built on September 8, 2026, completes the 693.

The propulsion system does not matter to a software fault of this kind. New Flyer says it determined the recall population by verifying a program condition tied to the hazard warning tell-tale function, and it counts all 693 buses as carrying the defect. A fuel-cell bus built in January 2015 and a compression-ignition XD40 built on September 8, 2026 are in the same recall, and the filing’s build dates run across that whole span. New Flyer says buses built from September 28, 2026 already leave the plant with updated software.

683 Motor Coach Industries coaches share the same code

The coach maker’s filing uses almost the same words. Motor Coach Industries, based in Des Plaines, Illinois, says in its Part 573 report for 26V645 that a U.S. customer of its affiliate New Flyer reported the problem, and that as a precaution it began validating its own programs for an ignition condition on the hazard indicators. Its chronology matches New Flyer’s date for date on September 16, 24 and 28. Its 683 coaches are mostly D45CRTLE, with 254 units, and D45CRT, with 244, plus 89 D4020ISTV, 56 D4520, 36 electric D45CRTELE, 2 D4020, and one each of the 2018 D4520 and 2024 D45CRTE.

Build dates run from September 2017 for the single 2018 D4520 to September 25, 2026, and coaches built since September 28, 2026 carry corrected software. The campaign record for 26V645000 gives the remedy in a single sentence: “MCI will update the software, free of charge.” Customer service for both campaigns is listed at the same number, 1-800-241-2947, and the New Flyer record names the same line.

A software update, applied in the field from October

Both remedies are software only, and the revision level determines the difference from the recalled version. New Flyer says it will provide software for affected buses starting October 2026, while Motor Coach Industries gives the same October start. Neither company lists dealer notification or an interim owner notice, and both say a general reimbursement plan is on file. Both say some customers may receive the update before the formal notice arrives, and the notice will say the update may already have been applied.

Planned owner notification dates are November 20, 2026 for New Flyer and November 24, 2026 for Motor Coach Industries. Both filings give drivers a way to cover the gap: whether the hazards are on can be confirmed by visually checking the position of the hazard lamp switch. Both reports were received on October 5, 2026, and both entries appear in NHTSA’s recall dataset for reports received September 29 through October 7. The companies told NHTSA that draft owner letters would go in for the agency’s review in late October, with customer mailings planned for mid-November and later in the month.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

Stay ahead on AI: Subscribe to The Deep View →

We may earn a commission if you sign up.