Mack Anthem (An), Mack Pioneer Pr (4), model years 2025 to 2026. Filed by Mack Trucks, Inc. and reported to NHTSA on 11 August 2025. 32 vehicles potentially affected.
What the notice says Mack Trucks, Inc. (Mack) is recalling certain 2025 Anthem and 2025-2026 Pioneer vehicles. The dynamic steering and oversteer guidance feature may malfunction and cause a loss of steering control.
Is your vehicle included? Check with your VIN at NHTSA, or ask a dealer. This page is an independent copy of the notice, kept so you can see what changed after it was published. It is not the authority, and the authority’s own text is the one to act on.
Mack's own number for this recall: SC0483. That is the number on the owner letter and on the dealer paperwork. 25V521 is the number NHTSA gave the same campaign, and the number this page is filed under. They are one recall, written two ways.
What owners ask about this recall
- Which vehicles does recall 25V521 cover?
- Mack Anthem (An), Mack Pioneer PR (4), model years 2025-2026.
- What is wrong with them?
- Mack Trucks, Inc. (Mack) is recalling certain 2025 Anthem and 2025-2026 Pioneer vehicles. The dynamic steering and oversteer guidance feature may malfunction and cause a loss of steering control.
- What can happen if it is not put right?
- A loss of steering control increases the risk of a crash.
- Is there a fix yet?
- Yes, and it is free. The oversteer guidance feature will be disabled through an over-the-air (OTA) update or by a dealer, free of charge. Owner notification letters were mailed August 21, 2025. Owners may contact Mack's customer service at 1-800-866-1177. Mack's number for this recall is SC0483.
- What should I do now?
- Check your own vehicle by its VIN with NHTSA, which is the record to act on. Mack calls this recall SC0483, which is the number on the owner letter and the dealer paperwork.
Answered from the register this site holds. NHTSA is the record to act on.
What the authority says can happen if this is not fixed: “A loss of steering control increases the risk of a crash.”
affected
in the notice
caught
| Campaign | 25V521 |
|---|---|
| Filed by | Mack Trucks, Inc. |
| System at fault | Steering |
| Reported to NHTSA | 11 August 2025 |
| Model years | 2025-2026 |
| Vehicles named | MACK ANTHEM (AN), MACK PIONEER PR (4) |
What the notice says today
The defect
Mack Trucks, Inc. (Mack) is recalling certain 2025 Anthem and 2025-2026 Pioneer vehicles. The dynamic steering and oversteer guidance feature may malfunction and cause a loss of steering control.
The consequence
A loss of steering control increases the risk of a crash.
The remedy
The oversteer guidance feature will be disabled through an over-the-air (OTA) update or by a dealer, free of charge. Owner notification letters were mailed August 21, 2025. Owners may contact Mack's customer service at 1-800-866-1177. Mack's number for this recall is SC0483.
What it said before
Nothing has changed while we have been watching. We last read the wording of this campaign on 17 September 2026, and it matched the copy we already held.
That copy hashes to 09e276b8d355805b4a9e1f320e5a6921…, so if it is ever edited the change is provable rather than a matter of memory.
This is one of 745 notices in the record whose component field names steering. Across that group the median wait before owners were written to was 39 days.
Last checked . No change has been recorded in the wording.
The models named here, across their whole recall history
How to cite this record
Quoting the wording on this page means quoting a version, so the date belongs in the citation:
CarsMultiverse, recall 25V521, wording as read on 17 September 2026. https://carsmultiverse.com/recall/25v521/
The copy quoted above hashes to 09e276b8d355805b4a9e1f320e5a6921…. If the notice is reworded later, that fingerprint will not match, which is how a reader checks that the quotation was of the version we say it was.
The cross-border matches used on this site are deposited as a citable dataset: doi:10.5281/zenodo.22087136. The recall wording itself is published by the national authority named above and is theirs, not ours.
The recall record and its wording are published by the US National Highway Traffic Safety Administration and are US Government public domain. The dated archive, the comparison and any before-and-after above are CarsMultiverse. How fresh every engine behind this page is, is public on the status page. To check a specific vehicle, use NHTSA’s own VIN lookup.
Other Mack notices we hold
- 26V515: 2027 Anthem AN (4) and Pioneer PR (4)
- 26V509: 2025 TerraPro trucks
- 26V351: 2026 Anthem (AN), 2026-2027 Pioneer PR (4), Pinnacle (PI/PN), Granite (GR), and 2027 Anthem AN (4)
- 26V261: 2025-2027 Pioneer (4) and 2026-2027 Anthem (4)
- 26V207: 2025-2027 Pioneer (4) and 2027 Anthem (4) trailers
- 26V139: 2022-2027 TerraPro trucks
- 26E055: Grote replacement marker lights with part number 78513681
- 25V867: 2010-2016 Granite (GU) trucks
All 113 Mack campaigns we hold · Every manufacturer in the record
The fingerprint of this notice
We take a SHA-256 of each of the three blocks of text the authority publishes and keep the first eight characters. As we last read campaign 25V521 on 23 August 2026, they were:
- Defect summary
637a17ce - Consequence
cbb1fbdc - Remedy
36e1324d
We first read this notice on 21 August 2026. It has not moved since. If it ever does, these characters will not match, and the change will be dated here.
The wording we hold for 25V521 · how the whole register is watched
This notice names one vehicle among several registers that have written about it. Every notice this site holds for the Mack Pioneer PR (4), in all seven, is kept on that vehicle's own page, with the newest in each.
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Owners of these cars
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