Mercedes-Benz bulletin LI09_40-N-079144
Mercedes-Benz filed this with NHTSA as a service bulletin dated Jun 29, 2026, received Jul 2, 2026, about the power train — 2 documents under this number: LI09.40-N-079144. It names 3 model years (2023–2025). A service bulletin is not a safety recall: it is the manufacturer telling its dealers how to diagnose or repair a condition, and whether the work is paid for depends on the warranty in force. Quoting the number at a service desk can save a diagnosis.
What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationComplaint The check engine light is activated, accompanied by one or more of the following fault codes related to the Boost Pressure Positioner: • P300A6D The boost pressure is too low. Charge Air Cooler. • P300974 Component 'Boost pressure positioner' has a malfunction. The boost pressure is too low. • P300DFB Component 'Boost pressure positioner' has a malfunction. • P300DE8 Boost pressure control A has a malfunction after the cold start. Cause The potential causes for these fault codes are: A. Leak or Blockage in the Intake or Charge Air System: This can prevent the proper flow of air, affecting the boost pressure. B. Insufficient Source Vacuum, Vacuum Leak, or Sticking/Weak Vacuum Component: These issues can prevent the boost pressure positioner from functioning correctly. • For Model Year 2023-Cuurent vehicles operating at approximately 4,000 ft elevation or above, reduced ambient pressure and/or high brake demand may contribute to reduced available vacuum differential and under boost com-plaints, even when no discrete vacuum component failure is identified. C. Internal Malfunction of the Boost Pressure Positioner: The component itself may be faulty. D. Internal Defect with the Variable Turbine Geometry (VTG) System inside the Turbocharger: Issues within the turbo-charger can affect boost pressure control. Remedy Engineering Review Required: For vehicles operating at approximately 4,000 ft elevation or above, a TIPS case MUST be opened before replacing any component for fault codes P300A6D, P300974, P300DFB, or P300DE8.
Documents filed under this number
| Document | Kind | Dated | NHTSA id |
|---|---|---|---|
| LI09_40-N-079144 | Service bulletin | Jun 29, 2026 | 11034408 |
| LI09.40-N-079144 | Service bulletin | Jun 3, 2026 | 11034409 |
The summary is NHTSA’s abstract of the document, as filed under 49 CFR 579.5; the full text comes from the manufacturer or a dealer. 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. Quote it at a service desk; it is what the dealer’s system is keyed on.
Model years it names
Source: as the manufacturer filed themA vehicle page’s bulletin list shows the newest few communications filed against that model year; the count there is every one.
Common questions
Source: NHTSA, 49 CFR 579.5Is Mercedes-Benz LI09_40-N-079144 a recall?
No. A service bulletin 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, or on its page here.
Is the LI09_40-N-079144 repair free?
Not automatically. A service bulletin describes how to diagnose or repair a condition; who pays depends on the warranty in force, any extension, and the dealer. Quoting the number can save a diagnosis either way.
Which vehicles does LI09_40-N-079144 cover?
The manufacturer filed it against 3 model years: 2025 Mercedes-Benz Sprinter, 2024 Mercedes-Benz Sprinter, 2023 Mercedes-Benz Sprinter. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.