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Federal filingsHome›Bulletins›Mercedes-Benz› LI09_41-N-079165_2_en
Manufacturer communication · Service bulletin

Mercedes-Benz bulletin LI09_41-N-079165_2_en

What it saysComplaint Low Coolant warning with possible engine misfire caused by a leaking Charge Air Cooler (Intercooler), accompanied by one or more of the following possible fault codes related to the coolant system: P30040B… NHTSA’s full summary ↓

Mercedes-Benz filed this with NHTSA as a service bulletin dated Aug 3, 2026, received Sep 4, 2026, about the engine. It names 4 model years (2023–2026). 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.

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What the bulletin says

Source: NHTSA's summary of the manufacturer's communication

Complaint Low Coolant warning with possible engine misfire caused by a leaking Charge Air Cooler (Intercooler), accompanied by one or more of the following possible fault codes related to the coolant system: P30040B: Component 'Temperature sensor downstream of charge air cooler' has an open circuit or short circuit to positive. P25567B: Sensor 'Coolant level' has a malfunction. The fluid level is too low. Cause The potential causes for this topic are: A. A leak in the Coolant System, other than the Charge Air Cooler. B. An Internal leak of the Charge Air Cooler. C. An unapproved/aftermarket upfit or modification to the coolant system. Remedy A. A leak in the Coolant System, other than the Charge Air Cooler 1. Complete a coolant system pressure test: •Refer to WIS Doc AR20.00‑D‑1011TS ‑ Check engine cooling system for leak tightness. •Use Tester Cap 210 589 00 91 and Pressure Pump 124 589 24 21 00. •Apply test pressure to the engine cooling system. Do not exceed the specified test pressure of 1.5 Bar to prevent damage to the engine cooling system. •Perform a visual check on the top and bottom of the engine compartment and in the vehicle interior. •If coolant loss or pressure loss is present, perform suitable repair measures depending on the vehicle equipment. •If NO signs of coolant loss are found but pressure loss is present, proceed to Step B. B. An Internal leak of the Charge Air Cooler 1. Inspect the Charge Air Cooler for an internal leak: •Remove either the Throttle Valve or Charge Air Temperature Sensor to inspect for coolant loss. See attachments for the failed Charge Air Cooler. •If coolant is found inside the Charge Air Cooler: •Perform a manual compression test to confirm the absence of internal engine failures per WIS Doc AR01.00‑D‑1201TSM ‑ Check compression pressure. •Remove and clean any coolant present in the Charge Air System, Intake System, and Cylinders. •Replace the Charge Air Cooler, the glow plugs, and then conduct an oil and filter change. Refer to AR09.41‑D‑6817TSM ‑ Remove/install charge air cooler. •If coolant is not found inside the Charge Air Cooler, proceed to Step C. C. An unapproved/aftermarket upfit or modification to the coolant system 1. Inspect the Coolant system for any unapproved/aftermarket upfits or modifications: •See the Attachments for examples of non‑approved upfits or modifications. •Note: The OM654 cannot have any a

Kind Service bulletin Manufacturer date Aug 3, 2026 Received by NHTSA Sep 4, 2026 Components Engine

Document filed under this number

DocumentKindDatedNHTSA idAt NHTSA
LI09_41-N-079165_2_enService bulletinAug 3, 202611036853PDF, 40 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 them

A vehicle page’s bulletin list shows the newest few communications filed against that model year; the count there is every one.

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What owners reported

Source: NHTSA complaint database

Owners of the 4 model years this bulletin names have filed 58 complaints with NHTSA since 2015. 6 of them name Engine — the same broad component group this bulletin is filed under. NHTSA groups complaints coarsely, so that means the same area of the vehicle, not necessarily the same fault.

The ECM harness was wired too close to a sharp metal piece within the engine bay, the clip MBZ uses to secure it was insufficient to hold it back, the thick wiring harness got caught on the metal piece and overtime got cut deeply causing a short with thermal issues spreading to other components, the wiring harness melted together and…

2023 Mercedes-Benz Sprinter · Engine · filed with NHTSA Oct 8, 2026 · ODI 11769942

Complaint Description I am filing this complaint with the National Highway Traffic Safety Administration regarding a safety issue with my new Mercedes Benz Sprinter 2500. I purchased this vehicle brand new from Mercedes Benz Manhattan. From the first day of ownership, I began experiencing multiple serious problems with the van.

2024 Mercedes-Benz Sprinter · Engine · filed with NHTSA Mar 15, 2026 · ODI 11724480

A complaint is one owner’s account, not a defect finding, and a bulletin is not a recall. Nothing here says this bulletin was issued because of these complaints, or that the repair it describes fixed them. Complaint files on this site begin in 2015.

More bulletins about the engine

Source: same model, same component group

32 other manufacturer communications filed against the Mercedes-Benz Sprinter under the same component group (engine), newest first. The eight newest are listed; the rest are on the Mercedes-Benz list.

NumberKindDatedNHTSA’s summary
LI20_10-N-080868_2_enService bulletinSep 2, 2026Coolant warning light (MIL) lights up on the display Complaint The coolant warning lamp may be displayed in the instrument cluster. The malf…
LI07.16-N-080731Service bulletinJun 18, 2026Complaint The customer reports an exhaust odor from the engine compartment, potentially accompanied by a check engine light and/or engine mi…
LI14.20-N-073867Service bulletinJun 15, 2026Complaint Complaint A: The engine is jolting/bucking between 1700 and 1900 rpm. Complaint B: One or more mechanical related fault codes for…
LI09.41-N-080666Service bulletinJun 3, 2026Check engine light with reduced power –P300A6D due to charge air system contamination Complaint The check engine light is activated, accompa…
LI05.30-N-080518Service bulletinJun 3, 2026OM654 Extended engine crank or starting concerns and/or poor running characteristics Complaint One or more of the following may be reported:…
LI4910-N-060969Service bulletinApr 18, 2026Complaint Rattling noise from underneath the vehicle. Cause One or more of the following conditions may be present: 1. The exhaust bracket f…
LI49.20-N-075995Service bulletinMar 23, 2026Vehicles with SCR Generation 4: SCR/AdBlue® warning message cannot be reset with fault code P13DF00 or P300685 Complaint SCR or AdBlue warni…
LI4920N078838Service bulletinFeb 24, 2026Check engine light or Adblue warning with fault codes P206B31, P203B31, or P300494 present in AdBlue (SCR) control unit (N118/5) Complaint T…

Quote the number at the service desk. It is what the dealer’s system is keyed on.

Every manufacturer communication NHTSA holds for Mercedes-Benz, by the number printed on the letter.

Photo: Christian Buehner / Unsplash

Common questions

Source: NHTSA, 49 CFR 579.5

Is Mercedes-Benz LI09_41-N-079165_2_en 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_41-N-079165_2_en 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. Every Mercedes-Benz warranty extension on file lists the ones Mercedes-Benz has filed.

Which vehicles does LI09_41-N-079165_2_en cover?

The manufacturer filed it against 4 model years: 2026 Mercedes-Benz Sprinter, 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.