Mercedes-Benz bulletin NCU-2024020012
What it saysThis is to notify you of the Service Campaign Launch to update the Engine Control Unit Software in 51234 Model Year ("MY") 2022- 2023 SL (232 platform). NHTSA’s full summary ↓
Mercedes-Benz filed this with NHTSA as a service bulletin dated Mar 1, 2024, received Mar 5, 2024, about the electrical system — 2 documents under this number: NCU - 2024020012 and 1 more. It names 3 model years (2022–2023). 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 communicationPicked out of NHTSA’s summary below, word for word. The document itself is the record, and the dealer checks the VIN.
This is to notify you of the Service Campaign Launch to update the Engine Control Unit Software in 51234 Model Year ("MY") 2022- 2023 SL (232 platform). The vehicles will be visible and flagged in VMI as "OPEN" on March 1, 2024. Mercedes-Benz AG ("MBAG"), the manufacturer of Mercedes-Benz vehicles, has determined that on certain MY 2022-2023 SL (232 platform) vehicles, the Engine Control Unit software might not correspond to the current production specifications. As a consequence, the engine fan may run for an excessive amount of time after the vehicle is shut off. MBUSA will conduct a service campaign. An authorized Mercedes-Benz dealer will update the Engine Control Unit software.
Documents filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| NCU - 2024020012 | Service bulletin | Mar 1, 2024 | 10252793 | PDF, 4,196 KB |
| NCU-2024020012 | Service bulletin | Feb 29, 2024 | 10251184 | PDF, 856 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 model years this site has no page for: 2022 Mercedes-Benz AMG SL43.
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 databaseOwners of the 2 model years this bulletin names have filed 10 complaints with NHTSA since 2015. 9 of them name Electrical System, 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.
My mom and I were in her car brand new Mercedes adaptive cruise was on the car started to act up with all the warning lights again, which shut all safety systems down air back seatbelts, adaptive cruise, Tronics and the engine wall between 18 wheeler and the freeway wall slammed the vehicle into the freeway hall causing about $5000 worth…
2023 Mercedes-Benz SL-Class · Electrical System · filed with NHTSA Jan 21, 2025 · ODI 11637467
The contact owns a 2022 Mercedes-Benz AMG SL55. The contact stated that upon entering the vehicle, the vehicle failed to detect the presence of the key, after which the vehicle failed to start. No warning lights were illuminated. The vehicle was taken to the dealer, who was unable to determine the cause of the failure.
2022 Mercedes-Benz SL-Class · Electrical System · filed with NHTSA Aug 19, 2024 · ODI 11609466
The electrical systems drains the two batteries after the car sits idle for a few hours. If it can be started, many of the safety features are inoperable until the car is driven for 30 or 40 minutes. I've had it to multiple Mercedes dealers and all they do is re-charge the battery and told me to get a trickle charger.
2022 Mercedes-Benz SL-Class · Electrical System · filed with NHTSA Sep 10, 2025 · ODI 11686246
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 electrical system
Source: same model, same component group72 other manufacturer communications filed against these Mercedes-Benz models under the same component group (electrical system), newest first. The eight newest are listed; the rest are on the Mercedes-Benz list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| LI54.30-P-080963 | Service bulletin | Sep 17, 2026 | Complaint Issue after OTA Update IC Odometer Reading blank("_ _ _ _") IC Maintanence data unavailable Cause OTA Update E61.0 Remedy In the I… |
| LI54.71-P-079104 | Service bulletin | Sep 11, 2026 | Complaint Traffic sign symbol for "Traffic Sign Assist" is blinking in instrument cluster without obvious cause usually with one of the foll… |
| LI82.85-P-079088 | Service bulletin | Aug 14, 2026 | Complaint The following most common complaints may be observed: • Brief connectivity interruptions when using Apple CarPlay over Wi-Fi • Aud… |
| LI54.65-P-080132 | Service bulletin | Aug 12, 2026 | Complaint 1. General Diagnostic Tips 2. One or More PARK Sensor Activations 3. Red Ring Around Vehicle 4. "Active Parking and Parking Assist… |
| LI54.10-P-080880 | Service bulletin | Aug 12, 2026 | Complaint Customer Complaint: - AC charging is not possible. - The departure time, charging pause, location-based charging or target SOC lim… |
| LI82.60-P-080806 | Service bulletin | Aug 4, 2026 | Complaint After an "Over the Air" update (OTA), FM or SDARS radio reception is limited; only a few stations are found. Cause The firmware in… |
| LI46.10-P-078012 | Service bulletin | Jul 17, 2026 | Complaint Hand detection system – malfunction / vehicles with code 266 Fault message in instrument cluster: "Active Emergency Stop Assist no… |
| LI00.20-P-077615 | Service bulletin | Jul 1, 2026 | The following symptoms may be present in the instrument cluster: 1. "Perform vehicle handover" in the workshop menu to start the maintenanc… |

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.
Common questions
Source: NHTSA, 49 CFR 579.5Is Mercedes-Benz NCU-2024020012 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 NCU-2024020012 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 NCU-2024020012 cover?
The manufacturer filed it against 3 model years: 2023 Mercedes-Benz SL-Class, 2022 Mercedes-Benz SL-Class, 2022 Mercedes-Benz AMG SL43. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.