Mack service campaign S4437- 202502
What it saysMack Trucks has identified that certain MMDE model trucks may encounter charging issues when using a Heliox brand charger. NHTSA’s full summary ↓
Mack filed this with NHTSA as a service campaign dated Feb 28, 2025, received Mar 3, 2025, about the fuel/propulsion system. It names 2 model years (2024–2025). A service campaign is not a safety recall — there is no NHTSA campaign number and no federal requirement — but it is usually work the manufacturer pays for on the vehicles it names; the dealer checks the VIN against the manufacturer’s list.
What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationMack Trucks has identified that certain MMDE model trucks may encounter charging issues when using a Heliox brand charger.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| S4437- 202502 | Service campaign | Feb 28, 2025 | 11014713 | PDF, 2,227 KB |
The summary is NHTSA’s abstract of the document, as filed under 49 CFR 579.5. One communication is usually filed as several documents — the bulletin, a dealer notice, an owner letter — and the number on any of them finds this page. A PDF link is shown only once NHTSA’s own server has been seen to serve that document; the rest are checked over the following nights. Quote the number at a service desk; it is what the dealer’s system is keyed on.
Model years it names
Source: as the manufacturer filed themAlso filed against: 2024 Mack MD (electric); 2025 Mack MD (electric).
None of these model years has a page on this site (it covers EPA-certified cars, trucks and SUVs from 2016), so the bulletin is listed here on its own.
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Mack, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is Mack S4437- 202502 a recall?
No. A service campaign is a manufacturer communication filed with NHTSA under 49 CFR 579.5; a safety recall carries an NHTSA campaign number (two digits, a letter, six digits) and a federal duty to repair for free. Check the vehicle’s recalls by VIN at nhtsa.gov/recalls.
Is the S4437- 202502 repair free?
A service campaign is usually paid by the manufacturer on the vehicles it names, within the terms and time limit the document sets; the dealer checks the VIN against the manufacturer’s list.
Which vehicles does S4437- 202502 cover?
The manufacturer filed it against 2 model years: 2024 Mack MD (electric), 2025 Mack MD (electric). Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.