Mack Trucks has recalled 2024 through 2026 MD Electric medium-duty trucks because they were built with the hill start assist message turned on when it should be off. Federal records list 151 potentially affected units. A truck showing that message on an incline can roll backward unexpectedly, which raises the risk of a crash.
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NHTSA received Mack’s report on Oct. 29 under campaign number 26V719000. The repair is a software and manual correction, and the dealer does the work at no charge.
A dashboard message that promises help the truck is not giving
According to the National Highway Traffic Safety Administration’s record, the vehicles carry a hill start assist notification that is incorrectly enabled. The summary says the trucks were “built with the hill start assist message incorrectly enabled,” so a driver who sees the message may release the brake on a grade expecting help that is not being given. The consequence listed is an unexpected rollback on an incline. The filing reads as a software and documentation defect more than a hardware one. Nothing in it describes a failed part, and the component category is the owner’s manual, not the brake system. The remedy follows that logic: dealers update the dashboard notification software and add a correction to the owner’s manual. The federal data lists no crashes or injuries tied to the message and no interim instruction beyond contacting Mack. Mack customer service answers at 1-800-866-1177, and the manufacturer’s internal recall number is SC0502.
The trucks at issue are not small. Mack’s introduction of the MD Electric lists gross vehicle weight ratings of 25,995 pounds in Class 6 and 33,000 pounds in Class 7, with peak output of 260 horsepower and 1,850 pound-feet of torque. Range is quoted at up to 140 miles with two batteries and 230 miles with three. Martin Weissberg, Mack’s global president, framed the truck at launch as central to the company’s push to decarbonize, and Mack Trucks North America president Jonathan Randall said at the launch that the truck would help customers meet sustainability goals “without sacrificing durability, reliability and total cost of ownership.” A loaded 33,000-pound truck that drifts backward on a grade gives a driver very little room to react, which is why a misleading on-screen prompt belongs in a recall even when no part has failed. Until letters arrive, the federal record offers drivers no workaround beyond the VIN search and the Mack customer line. The federal filing does not say which weight class or body type the 151 units carry, so the real-world exposure depends on how fleets use them.
Counting 151 units across three model years
The federal database lists the campaign three times, once each for model years 2024, 2025 and 2026, and each entry shows 151 potential units. The data does not give a combined total, so the sum could be 151 vehicles spread across the three years or a repeated figure; the record does not settle it. The summary refers to “certain” 2024-2026 medium-duty electric vehicles. Those are small numbers for a heavy-truck maker. Mack’s October 2025 seat-belt anchorage recall covered about 15,841 trucks across several lines, including the 2024 MD Electric, and was caused by an improperly welded bracket. The latest campaign is roughly a hundredth of that size.
Owner letters, the 60-day clock and the VIN search
NHTSA expects owner notification letters to be mailed on Dec. 28, which sits 60 days after the Oct. 29 report. That matches the agency’s published rule that manufacturers must mail registered owners within 60 days of notifying it of a recall decision, as described on NHTSA’s recall lookup page. Affected VINs became searchable on NHTSA.gov starting Nov. 5. The lookup page notes limits worth knowing for fleet managers: a recently announced recall may not yet list all affected VINs, and the tool will not show recalls that have already been repaired. Owners of medium-duty electrics tend to be fleets, so a depot manager can search many VINs at once, up to 100 per query.
The campaign is also not Mack’s first brush with this model. A 2024 recall, added to the federal database on June 4, 2024, covered 24 MD Electric vehicles whose battery management software could shut down the high-voltage battery, causing a sudden loss of steering control and drive power. Letters in that case went out on July 10, 2024. A different hill-related defect surfaced at a rival in August 2025. International Motors recalled more than 1,000 trucks after the Hill Start Assist exhaust port could be blocked by ice or debris, which could keep the service brakes from releasing. In that case a part was at fault. In Mack’s case, a message was.
What is still open is the gap between report and fix. Owner letters are due Dec. 28, and the filing gives no date for when the software will be ready, so trucks may run with a misleading prompt into the new year.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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