smart bulletin LI82.70-P-077433
smart filed this with NHTSA as a service bulletin dated Mar 5, 2025, received Sep 28, 2024, about the electrical system — 2 documents under this number. It names 4 model years (2016–2019). 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 During a phone call, the called party has difficulty understanding/cannot understand the driver, or interference/background noises are audible to the called party during a call. It becomes increasingly difficult to understand as the speed rises. Cause A. Seating of the microphones in the headliner. Side edges are covered by the textile cover (see picture "1") B. Assembly of microphones (B25/20 or B25/21) in the headliner. C. Dirt inside the microphone housing Remedy 1. Press finger on rear of microphone (on adhesive tape) 2. Remove microphone cap from the front 3. Eliminate protruding material residues of the microphone cutout at the headliner, e.g. with a soldering iron. The microphone must be seated in the headliner as shown in picture "2". 4. Push microphone from behind until it is firmly pressed into the headliner 5. Maintain pressure and press/clip cap into microphone from the front. Note: The cover cap must be clearly heard and felt to engage. 6. This procedure must be carried out on both microphones (B25/20 and B25/21) Note: • It is recommended to replace the cover caps. • The non-woven cloth in the cover cap protects the microphone from soiling and must not be removed. NOTE: The information contained in this document is intended for use by trained, professional technicians with the knowledge to properly and safely perform diagnosis and repairs on Mercedes-Benz vehicles, using Mercedes-Benz approved tools and equipment. It informs service technicians about conditions that could occur in certain vehicles and provides information that could assist in proper vehicle diagnosis, service, or repair. It does not indicate that a defect is present in any vehicle referenced in this document nor does it imply warranty coverage. DO NOT assume that a symptom or condition, or a described cause of a symptom or condition, affects any particular vehicle or groups of vehicles, or that a described repair applies to any particular vehicle or groups of vehicles. There can be multiple causes resulting in the same or similar symptoms or conditions described in this document, and trained professional service technicians must use their diagnostic skills to make evaluations on a case-by-case basis. The information contained in this document does not guarantee warranty coverage nor does it extend the vehicle’s warranty in any way.
Documents filed under this number
| Document | Kind | Dated | NHTSA id |
|---|---|---|---|
| LI82.70-P-077433 | Service bulletin | Mar 5, 2025 | 11015640 |
| LI82.70-P-077433 | Service bulletin | Sep 28, 2024 | 11008091 |
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 smart LI82.70-P-077433 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 LI82.70-P-077433 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 LI82.70-P-077433 cover?
The manufacturer filed it against 4 model years: 2019 smart fortwo, 2018 smart fortwo, 2017 smart fortwo, 2016 smart fortwo. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.