Mercedes-Benz bulletin LI20.00-P-074205
What it saysComplaint Yellow Coolant warning comes on in cluster Fault codes below are current or stored in MED41 P0A0500- The actuation of the circulation pump for the low-temperature circuit has an open circuit. NHTSA’s full summary ↓
Mercedes-Benz filed this with NHTSA as a service bulletin dated Jul 20, 2024, received Jul 30, 2024, about the engine. It names 15 model years (2018–2023). 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 communicationComplaint Yellow Coolant warning comes on in cluster Fault codes below are current or stored in MED41 P0A0500- The actuation of the circulation pump for the low-temperature circuit has an open circuit. P00B700- The coolant flow is too low. P0C7300- Circulation pump 1 for the low-temperature circuit has a malfunction. Cause Air may be trapped in the coolant circuit for transmission cooler Remedy Check coolant level. -If coolant level is low, locate source of leak and correct. -If coolant level is ok, perform procedure in attached instructions to bleed the coolant circuit to transmission cooler. 1. Allow cooling system to cool to ambient temperature. 2. Fill coolant reservoir completely. 3. Slightly open coolant connection shown in attachment (red arrow) to allow air to escape. 4. Once coolant flows out, close connection and correct coolant level. 5. Clear fault codes and check for further symptoms.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| LI20.00-P-074205 | Service bulletin | Jul 20, 2024 | 11005314 | PDF, 367 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 themA 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 15 model years this bulletin names have filed 773 complaints with NHTSA since 2015. 204 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.
My 2020 E450 has not been serviced on schedule due to Mercedes-Benz of Indianapolis and its service manger banning and blacklisting me for months. This service department would not allow my vehicle to be serviced under a prepaid maintenance and wheel and tire plan, and most importantly my vehicle's warranty.
2020 Mercedes-Benz E-Class · Engine · filed with NHTSA Jul 13, 2026 · ODI 11749901
Engine runs rough and activates a flashing engine light. Sounds like the engine is misfiring. On two occasions the engine stalled,(no power steering, brakes...) luckily not in a dangerous situation. No engine codes were visible to a technician when try to diagnose. Car seemed to run fine again after restart
2019 Mercedes-Benz GLC-Class · Engine · filed with NHTSA Aug 21, 2025 · ODI 11682158
Engine keeps having a misfire that Mercedes put a TSB out for and once the misfire happen I cause the vehicle to go in a limp mode which causes the vehicle to loose power happened to me in the freeway. The car had 54K miles and Mercedes refused to repair the issue as the engine part failure isn’t common
2021 Mercedes-Benz E-Class · Engine · filed with NHTSA Dec 27, 2025 · ODI 11707258
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 group51 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 |
|---|---|---|---|
| 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… |
| LI20.10-P-075374 | Service bulletin | Sep 17, 2026 | Complaint Red coolant warning in instrument cluster. Fault codes U019F00 or U019F87 current/stored in MRG1 control unit. Cause Various cause… |
| PSL-NCU Return Parts 8/14 | Other | Aug 15, 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… |
| 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… |
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 LI20.00-P-074205 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 LI20.00-P-074205 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 LI20.00-P-074205 cover?
The manufacturer filed it against 15 model years: 2023 Mercedes-Benz C-Class, 2022 Mercedes-Benz C-Class, 2021 Mercedes-Benz C-Class, 2020 Mercedes-Benz C-Class, 2019 Mercedes-Benz C-Class, 2018 Mercedes-Benz C-Class and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.