Mercedes-Benz bulletin PSL-NCU Return Parts 8/21
What it saysDear Mercedes-Benz USA Dealers, The part numbers listed in the chart below should no longer be installed, and any existing stock must be returned to your facing PDC. NHTSA’s full summary ↓
Mercedes-Benz filed this with NHTSA as a manufacturer communication dated Aug 21, 2026, received Aug 25, 2026, about the power train. It names 6 model years (2021–2026). A manufacturer communication 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.
Get the next Mercedes-Benz GLA-Class bulletin by email Weekly, only when something new is filed. Nothing else; one-click unsubscribe.
What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationDear Mercedes-Benz USA Dealers, The part numbers listed in the chart below should no longer be installed, and any existing stock must be returned to your facing PDC. The deadline for all dealer returns is no later than Thursday, September 10th, 2026. After September 10th, returns of these parts will no longer be accepted. These parts should be returned via ZSR Special Return, using item category SCM Authorized Part Return. Please include a copy of this NCU as your authorization to return these parts. This procedure will not affect your return allowance. All returned parts will be replaced in accordance with the chart provided below.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| PSL-NCU Return Parts 8/21 | Other | Aug 21, 2026 | 11036343 | PDF, 124 KB |
What the document itself lists
The manufacturer titles it “Notice to Return Parts DATE: August 21, 2026”.
Parts the bulletin names
| Part number | Description | Qty | Find it |
|---|---|---|---|
| A1773307201 | — | — | |
| A1773305802 | — | — |
Read by machine from the document NHTSA serves (1 page), read Sep 30, 2026. A part number is shown only where it matches Mercedes-Benz’s own catalogue shape, an operation only with its code and time, and a description only where the reader got it whole; anything it could not settle is left out, and the PDF is the record. Times are the manufacturer’s warranty allowances, not a quote. Listings and prices on eBay Motors are the seller’s.
Affiliate disclosure: some links on this page are affiliate links. If you request a quote or buy through them we may earn a commission at no extra cost to you. Nothing on this page changes because of it.
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.
Email me new Mercedes-Benz bulletins for the GLA-Class
A weekly email, sent only in a week when Mercedes-Benz files something new with NHTSA for the model you pick — service bulletins, campaigns, warranty extensions, over-the-air notices, every model year. Nothing else is sent; one-click unsubscribe in every message. Separate from recall alerts.
What owners reported
Source: NHTSA complaint databaseOwners of the 6 model years this bulletin names have filed 44 complaints with NHTSA since 2015. 4 of them name Power Train — 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 contact owns a 2025 Mercedes-Benz GLA250. The contact stated that while his wife was stopped at a traffic light and attempting to depress the accelerator pedal, the vehicle failed to respond as intended. The vehicle shut off unexpectedly, and the gear shifter ceased. A dealer was contacted.
2025 Mercedes-Benz GLA-Class · Power Train · filed with NHTSA Mar 26, 2026 · ODI 11727233
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 power train
Source: same model, same component group10 other manufacturer communications filed against the Mercedes-Benz GLA-Class under the same component group (power train), newest first. The eight newest are listed; the rest are on the Mercedes-Benz list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| LI 27.10-P-080851 | Service bulletin | Aug 29, 2026 | Complaint Intermittent shift feel or thud/clunk noise perceived, such as a brief jerk or transmission reaction during certain driving situat… |
| LI27.19-P-080823 | Service bulletin | Aug 25, 2026 | Complaint Customers may report one or more of the following: • Transmission malfunction message • Check engine light illuminated • Shifts in… |
| LI35.30-P-058566 | Service bulletin | Jul 14, 2026 | Complaint Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end). The noise is heard once… |
| LI35.31-P-074854 | Service bulletin | Jan 23, 2026 | Complaint Noises from the rear axle differential, particularly when cornering slowly Cause Small quantity of water entering into oil of mult… |
| LI27.19-P-080155 | Service bulletin | Dec 19, 2025 | Complaint Oil residue in connector of transmission control unit in dual-clutch transmission models 724.0 and 724.1. Cause As part of the pro… |
| LI33.30-P-056665 | Service bulletin | Nov 15, 2025 | Complaint Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end). The clunk is heard once… |
| LI35.31-P-077429 | Service bulletin | Oct 29, 2025 | Instrument cluster message "4MATIC inoperative". The following fault code may be present in all-wheel drive control unit N15/17: P147354 - E… |
| LI27.19-P-072588 | Service bulletin | Sep 17, 2025 | Complaint Transmission control unit Y3/8n4 (fully integrated transmission control unit (VGS)) not listed in quick test and/or no communicati… |
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 PSL-NCU Return Parts 8/21 a recall?
No. A manufacturer communication 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 PSL-NCU Return Parts 8/21 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 PSL-NCU Return Parts 8/21 cover?
The manufacturer filed it against 6 model years: 2026 Mercedes-Benz GLA-Class, 2025 Mercedes-Benz GLA-Class, 2024 Mercedes-Benz GLA-Class, 2023 Mercedes-Benz GLA-Class, 2022 Mercedes-Benz GLA-Class, 2021 Mercedes-Benz GLA-Class. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.