Mercedes-Benz bulletin LI20.10-P-075374
What it saysComplaint Red coolant warning in instrument cluster. NHTSA’s full summary ↓
Mercedes-Benz filed this with NHTSA as a service bulletin dated Sep 17, 2026, received Dec 5, 2022, about the engine — 2 documents under this number. It names 59 model years (2016–2027). 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 communicationComplaint Red coolant warning in instrument cluster. Fault codes U019F00 or U019F87 current/stored in MRG1 control unit. Cause Various causes Remedy Perform guided test for fault code U019F with XENTRY diagnosis. Verify the following connections are clean and tight. Correct any problems and retest pump actuation: ‑12V plug at M75/11 ‑48V plug at M75/11 ‑48V connector X192/4 ‑Connections at 48V fuse box F153/2 ‑Sockets 1,2, and 5 at connector 2 of MRG1 control unit ‑M75/11 circuit 41 ground If actuation and above connections are OK, but resistance between M75/11 and engine block is less than 2 ohms or heat shield touching coolant pump, proceed with below steps. 1‑Modify engine insulation per attached instructions. 2‑Remove engine control module and measure continuity within control unit between connector 2 pin 1 and connector 6 pin 2. 2a‑If open circuit is found, replace engine control unit (MRG1) and perform initial startup. Refer to XENTRY parts information group 54/054 item 300. 3‑Clear faults and verify M75/11 operating normally.
Trouble codes it names: U019F
Documents filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| LI20.10-P-075374 | Service bulletin | Sep 17, 2026 | 11038176 | PDF, 33 KB |
| LI20.10-P-075374 | Service bulletin | Nov 10, 2022 | 10227141 | not found |
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 themand 4 more on this site: 2024 Mercedes-Benz S-Class, 2023 Mercedes-Benz S-Class, 2022 Mercedes-Benz S-Class, 2021 Mercedes-Benz S-Class.
Also filed against model years this site has no page for: 2021 Mercedes-Benz AMG E53 S; 2022 Mercedes-Benz AMG E63S; 2022 Mercedes-Benz AMG GT63; 2022 Mercedes-Benz AMG GT63 S; 2024 Mercedes-Benz AMG GT63 S E; 2024 Mercedes-Benz AMG GT63 S E Performance; 2026 Mercedes-Benz AMG GT63 S E Performance 4MATIC+; 2024 Mercedes-Benz AMG S 63 E 4MATIC+; 2026 Mercedes-Benz AMG S 63 E 4MATIC+; 2018 Mercedes-Benz E 400 4MATIC Cabriolet; 2018 Mercedes-Benz E 400 4MATIC Wagon; 2019 Mercedes-Benz E 450 4MATIC Cabriolet; 2020 Mercedes-Benz E 450 4MATIC Cabriolet; 2019 Mercedes-Benz E 450 4MATIC Wagon; 2020 Mercedes-Benz E 450 4MATIC Wagon.
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 44 model years this bulletin names have filed 1,292 complaints with NHTSA since 2015. 283 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.
Multiple engine ignition coils have failed on this low mileage vehicle. History of failures are as followed. 1/18/2022 Mileage 39,246 Ignition Coil #4 6/16/2022 Mileage 40,915 Ignition Coil #2 3/16/2023 Mileage 43,866 Ignition Coil #6 and #2 4/23/2023 Mileage 44,275 Ignition Coil #1 1/15/2025 Mileage 51,560 Ignition Coil #4 Mercedes Benz…
2016 Mercedes-Benz GLE-Class · Engine · filed with NHTSA Jan 18, 2025 · ODI 11636782
I brought my car in for routine service and was told I needed a rear main seal. I had the car inspected when I purchased it appx 13k miles ago because I saw online there was a lot of people having this issue with their vehicles. It’s a known manufacturer defect. At that time there was no issue. Now at 40k miles it began to leak.
2019 Mercedes-Benz E-Class · Engine · filed with NHTSA Jan 4, 2026 · ODI 11708627
On July 7, 2026, my 2022 Mercedes-Benz GLE 350 experienced a serious engine malfunction. After stopping at a traffic light, the engine began shaking violently and idling roughly. When the traffic light turned green, the vehicle accelerated extremely slowly and had very little power, making it difficult to clear the intersection.
2022 Mercedes-Benz GLE-Class · Engine · filed with NHTSA Jul 13, 2026 · ODI 11749953
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 group58 other manufacturer communications filed against these Mercedes-Benz models under the same component group (engine), newest first. The eight newest are listed; the rest are on the Mercedes-Benz list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| LI20.00-P-080222 | Service bulletin | Oct 23, 2026 | Complaint Customer states that the yellow "Coolant" message is populated in the instrument cluster. The following DTC is found stored in th… |
| LI18.00-P-073137 | Service bulletin | Sep 26, 2026 | Complaint Sporadic warning message in instrument cluster "Engine oil pressure stop switch off vehicle" (or similar) is shown in red on vehi… |
| LI01.20-P-080884 | Service bulletin | Aug 12, 2026 | Complaint Oil leaks found on M176 or M177 engines diagnosed to be from the cylinder head cover area Cause Unknown (under investigation) Reme… |
| LI07.10-P-080384 | Service bulletin | Aug 7, 2026 | Complaint Customer reports Check Engine Light with possible loss of power concern. The Following DTC's are present • P210185 - The throttle… |
| NCU - 2026010004 | Service campaign | Jul 27, 2026 | • Always use the latest XENTRY Diagnosis software release with all available add-ons. • Make sure to follow the operation steps exactly as d… |
| LI20.10-P-072886 | Service bulletin | Jul 24, 2026 | Complaint Check Engine Light ON with DTC P012800 "The Coolant Temperature is Below the Specified Temperature" active and/or stored in the ME… |
| Emissions - 2024100016 | Emissions | Jul 24, 2026 | Mercedes-Benz AG (“MBAG”), the manufacturer of Mercedes-Benz, has determined that on certain MY 2019-2021 C-Class, G-Class, GLC, GT, S-Class… |
| PSL-NCU Return Parts 6/19 | Other | Jun 19, 2026 | Dear Mercedes-Benz USA Dealers, The part numbers listed in the chart below should no longer be installed, and any existing stock must be ret… |
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 LI20.10-P-075374 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 LI20.10-P-075374 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 LI20.10-P-075374 cover?
The manufacturer filed it against 59 model years: 2026 Mercedes-Benz AMG GT, 2025 Mercedes-Benz AMG GT, 2024 Mercedes-Benz AMG GT, 2023 Mercedes-Benz AMG GT, 2022 Mercedes-Benz AMG GT, 2021 Mercedes-Benz AMG GT and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.