PACCAR service campaign 37-004
What it saysPACCAR MX-13 VECU3 Software Update - Certain heavy-duty chassis equipped with a PACCAR MX-13 engine are eligible for a Vehicle Electronic Control Unit (VECU3) software update. NHTSA’s full summary ↓
PACCAR filed this with NHTSA as a service campaign dated Mar 27, 2026, received Apr 7, 2026. It names 15 model years across Kenworth and Peterbilt (2024–2026). 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.
One page for every brand it was filed under. Each brand’s bulletins: Kenworth · Peterbilt.
What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationWhat it applies to, as the document itself states it — the build window in the manufacturer’s own words, read by machine from the PDF NHTSA serves. The build date is on the certification label in the driver’s door jamb; the dealer settles a borderline vehicle by its VIN.
PACCAR MX-13 VECU3 Software Update - Certain heavy-duty chassis equipped with a PACCAR MX-13 engine are eligible for a Vehicle Electronic Control Unit (VECU3) software update.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| 37-004 | Service campaign | Mar 27, 2026 | 11030933 | PDF, 382 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 themKenworth 6 model years
Also filed against: 2024 Kenworth T680; 2025 Kenworth T680; 2026 Kenworth T680; 2024 Kenworth T880; 2025 Kenworth T880; 2026 Kenworth T880.
Peterbilt 9 model years
Also filed against: 2024 Peterbilt 567; 2025 Peterbilt 567; 2026 Peterbilt 567; 2024 Peterbilt 579; 2025 Peterbilt 579; 2026 Peterbilt 579; 2024 Peterbilt 589; 2025 Peterbilt 589; 2026 Peterbilt 589.
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 Kenworth and Peterbilt, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is PACCAR 37-004 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 37-004 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 37-004 cover?
The manufacturer filed it against 15 model years across 2 brands (Kenworth and Peterbilt): 2024 Kenworth T680, 2025 Kenworth T680, 2026 Kenworth T680, 2024 Kenworth T880, 2025 Kenworth T880, 2026 Kenworth T880 and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone. The document itself sets the build window: built 26 Jun 2023 – 4 Sep 2025; built 19 Jun 2023 – 4 Dec 2025 — the build date is on the certification label in the driver’s door jamb.