Mack bulletin M0304 EC0033 202606
What it saysMack Trucks has determined that certain vehicles equipped with a model year (“MY”) 2017-2018 MP8 Turbo Compound (TC) engine may not meet California and Federal Regulations (CARB). NHTSA’s full summary ↓
Mack filed this with NHTSA as an emissions communication dated Jun 29, 2026, about the engine. It names 5 model years (2018–2019). An emissions communication 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 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.
Mack Trucks has determined that certain vehicles equipped with a model year (“MY”) 2017-2018 MP8 Turbo Compound (TC) engine may not meet California and Federal Regulations (CARB). This Recall is for updated software that will reduce the amount of time necessary for the system to operate in a cold engine warm-up strategy and provide health monitoring of the Selective Catalyst Reduction (SCR).
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| M0304 EC0033 202606 | Emissions | Jun 29, 2026 | 11034136 | PDF, 693 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: 2018 Mack Anthem (an); 2019 Mack Anthem (an); 2018 Mack CXU; 2018 Mack Pinnacle (pi/pn); 2019 Mack Pinnacle (pi/pn).
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.
More bulletins about the engine
Source: same model, same component group14 other manufacturer communications filed against these Mack models under the same component group (engine), newest first. The eight newest are listed; the rest are on the Mack list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| S4533 202608 | Service campaign | Aug 5, 2026 | Mack Trucks has determined that certain AN model trucks equipped with an MP8 Turbo Compound (TC) engine may experience TC Double Idler Gear… |
| M0039 032026 | Emissions | Mar 2, 2026 | Emissions - EC0039 MST21 Failure to Detect P20EE - AN, CHU. |
| M0302 022026 | Emissions | Feb 1, 2026 | Emissions - Mack Trucks has determined that certain vehicles equipped with a model year (“MY”) 2017-2018 MP7 engine may not meet California… |
| S4533 072025 | Service campaign | Jul 1, 2025 | SC - Mack Trucks has determined that certain AN model trucks equipped with an MP8 Turbo Compound (TC) engine may experience TC Double Idler… |
| M0350 202504 | Emissions | Apr 2, 2025 | ER - Mack Trucks has identified that the Selective Catalyst Reduction (SCR) system in certain vehicles equipped with the MY 2017 or 2018 MP8… |
| M0311 202410 | Emissions | Oct 25, 2024 | EMISSION RECALL - SCR Replacement |
| M0310 202410 | Emissions | Oct 25, 2024 | EMISISON RECALL - SCR Replacement. |
| M0296 202410 | Emissions | Oct 1, 2024 | Emission Recall - Mack Trucks has determined that certain vehicles equipped with a model year (“MY”) 2022-2024 MP8 model engines, may be equ… |
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 M0304 EC0033 202606 a recall?
No. A emissions communication 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 M0304 EC0033 202606 repair free?
A emissions communication 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 M0304 EC0033 202606 cover?
The manufacturer filed it against 5 model years: 2018 Mack Anthem (an), 2019 Mack Anthem (an), 2018 Mack CXU, 2018 Mack Pinnacle (pi/pn), 2019 Mack Pinnacle (pi/pn). 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 on or after 24 Jan 2017 — the build date is on the certification label in the driver’s door jamb.