2021 Mercedes-Benz GLA 250 4MATIC

On 7/17/26, while driving at highway speed, the check engine light illuminated and the vehicle lost power and shut off. I safely pulled over. It would not restart; a red battery warning displayed. Towed to Mercedes-Benz of Wilkes-Barre, RO #8388432. Dealer found battery severely discharged, replaced it, then found engine would not turn by hand. Diagnosis: internal engine damage/seized; recommended full engine replacement, est. $20,128, on a 2021 GLA 250 with 82,137 miles. MBUSA TSB MC-10241534-0001 (8/4/2023) extends the emission warranty on the exhaust valve assembly (cylinder head, exhaust valves, valve seat rings/guides) on the M260 2.0L turbo engine from 4yr/50k mi to 15yr/150k mi, covering MY2021-2022 GLA 250. My vehicle falls within this window. The bulletin's defect (valve guide/seat wear causing misfire and MIL activation) is consistent with the check engine light observed at failure. I have repeatedly asked MBUSA in writing to confirm whether the DTCs referenced in this bulletin were pulled/reviewed, and whether my case was cross-checked against the bulletin before any offer. MBUSA has not provided a written response. Reps made verbal offers ($2,100 toward the engine; separately $800.20 "service credit" equal to a battery charge that does not appear to have been performed), and on one call described the bulletin as "only a sensor issue," inconsistent with its own text. Filing to document a possible unaddressed engine defect on a GLA 250 within this TSB's covered model years, and concern that vehicles with catastrophic seizure may not be evaluated against this known condition before being treated as ordinary out-of-warranty repairs.

NHTSA ID

11765458

Incident

Jul 17, 2026

I recently purchased my vehicle with under 30k miles in July of 2026. Not long after my purchase my car began roughly idling with a blinking check engine light, and soon after the engine began misfiring. This also cause loss of power when attempting to accelerate creating dangerous conditions in high traffic/fast paced areas. After lots of research I found several reports of owners with cylinder failures. The dealership only responded to fixing the issue after calling them out directly on the issue.

NHTSA ID

11729834

Incident

Apr 6, 2026

Component/System: Engine cooling and lubrication system. Coolant was found mixing with engine oil (milky oil), indicating internal engine failure (I was informed it could be oil cooler/housing, thermostat, head gasket, or related components). Vehicle is currently at an authorized Mercedes-Benz dealership and available for inspection. The front left inner lining of my front break pad also "failed" inspection and the other 3 front break pads say "caution" and I never received a notification or warning about my breaks. Safety Risk: Coolant contamination of engine oil can cause sudden engine failure or loss of power without warning, creating a serious safety risk while driving, especially at highway speeds. There was no indication that engine oil was mixing with coolant, check engine light failed to illuminate/ no diagnostic warning illuminated. The condition was discovered incidentally during routine maintenance, which prevented any opportunity for corrective action prior to the failure. Confirmation: The condition was confirmed by an authorized Mercedes-Benz dealership during routine maintenance. The dealership stated the failure was not caused by owner misuse.Inspection: Vehicle has been inspected by an authorized Mercedes-Benz dealership (manufacturer representative). No police or insurance inspection occurred, as there was no accident or external event. Warnings/Symptoms: No check engine light or diagnostic warning ever illuminated. The issue was discovered incidentally after I received a low battery voltage notification and a routine maintenance reminder indicating service was due in approximately 1,000 miles, which I arranged promptly. The manufacturer will not perform full diagnostic teardown to determine the root cause unless I pay approximately $3,000 out of pocket. Link to video: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11715960

Incident

Jan 27, 2026

Complaint Temporary no start condition with check engine light and multiple warning messages. When performing a quick test, the following fault code is stored in Y3/14 ‑ Transmission control for 8‑speed dual‑clutch transmission (DKG): P24F100 The wake‑up line of the control unit has a short circuit to positive. Cause Possible signal timing between EZS control unit and Transmission Control Unit (DKG) Remedy As of 7/15/2026, new SCN coding is available for the EZS control unit. IPR will advise to open a TIPS case for EZS (N73), this is due to GLA models requiring support for SCN coding procedure. GLB (X247) and CLA (118) No TIPS case necessary. 1. SCN coding of EZS Control Unit 2. Clear all faults and perform extended road test with multiple drive cycles GLA (H247) Special function password required. 1. Verify if special procedure Central Locking ‑ Development Data is present in EZS (figure 1) 2. Submit a TIPS case to the Powertrain Inbox with the following information: ‑ Initial Quick Test w/ freeze frame data ‑ IPR Result ‑ DKG Control Unit Log ‑ EZS Control Unit Log ‑ Initial EEPROM data ‑ EZS special procedure menu If the vehicle has had this LI performed and P24F100 has returned, please submit a TIPS case to the Powertrain Inbox.

Complaint Intermittent shift feel or thud/clunk noise perceived, such as a brief jerk or transmission reaction during certain driving situations. May be most noticeable when transitioning from a coasting condition to accelerator pedal application. May occur in all drive modes. Cause Dual‑clutch transmissions (DCT) inherently exhibit more dynamic shifting behavior compared to other types of transmissions. This is due to the use of physical clutches for starting and gear changes. In certain situations, dynamic driving behavior can lead to a slight jerk sensation which is a normal technical characteristic of the transmission. A typical example is a "Change of Mind" situation: • The customer is coasting towards a red traffic light. • The traffic light turns green while the vehicle is still coasting. • The customer then presses the accelerator pedal. In these situations, a slight jerk may occur briefly because the transmission must quickly engage the appropriate gear and control the clutches accordingly. Since shift forks are responsible for engaging the gears during shifting, a slight shifting noise may also be noticeable. Please note driving programs S, S+, and M are designed to provide sportier vehicle behavior and are not optimized primarily for maximum comfort, so this operation may be more audible. Remedy Verify the customer's concern and confirm proper transmission operation. If no faults or abnormal operating conditions are identified by IPR (Intelligent Predictive Repair), no hardware replacement is necessary. Inform the customer that the transmission has been designed to provide direct gear engagement and responsive vehicle performance. Under certain operating conditions, brief shift sensations may be perceptible and are consistent with the operating characteristics of the dual‑clutch transmission

Complaint Customers may report one or more of the following: • Transmission malfunction message • Check engine light illuminated • Shifts into N • Concern disappears after ignition cycle When performing a quick test, the following fault code is stored in Y3/14 ‑ Transmission control for 8‑speed dual‑clutch transmission (DKG): P056300 The on‑board power supply voltage is too high. Cause An overvoltage condition is detected exclusively within the transmission control unit, storing fault P056300 once the measured voltage exceeds 16V. Remedy This LI applies if the freeze frame data for P056300 show a supply voltage between 15.75 to 16.50 volts, and no other control units report overvoltage. (figure 1) Long Term Resolution: Software resolutions have been released. Check validity and ensure your Xentry is updated with latest Addons before continuing: 1. Perform software update for Y3/14 ‑ Transmission control for 8‑speed dualclutch transmission (DKG) available software listed in Parts 2. Clear fault memory and perform final test drive If the customer complaint matches this LI and the software currently installed on the vehicle is not listed, please submit a TIPS case to the Powertrain inbox with the following information: ‑ Initial Quick Test w/ Freeze Frame Data ‑ DKG Control Unit Log ‑ Latest EEPROM data ‑ Screenshot of software availability

Complaint Tailgate opens unintentionally. Cause Accidental or unnoticed activation of the button to open the tailgate on the vehicle key. EXAMPLE: when stored in trouser pocket, handbag etc. Remedy As of the 6th generation, the vehicle key can be recoded so that the tailgate no longer opens as a result of a long press on the button, but by double‑clicking on the button instead. This reduces the likelihood of the button being activated accidentally or unintentionally. The recoding can be carried out as follows: 1. Add SA Code O19 into VeDoc (O for Oscar, not "zero") • an XSS ticket may be necessary to add the SA code 2. Perform SCN coding of EIS N73 control unit 3. Deactivate the vehicle key (a successful deactivation is indicated by the LED lighting up 2x briefly and then 1x for a long period). 4. Place the vehicle key in the storage compartment on the key symbol and turn on the ignition. IMPORTANT: all other vehicle keys must be outside the recognition range of the vehicle when doing this! Perform steps 3 and 4 successively for all vehicle keys. Notes: 6th, 7th and 8th generation keys can be deactivated as follows: Up to modification year 22/1 by double clicking the "Lock button" As of modification year 22/1, by press and holding the “Lock button", then double‑click the “Unlock button" at the same time. On model series 167, the storage compartment with the key symbol is located in the armrest. The SCN coding from the EZS is only transferred correctly to the vehicle key under the following conditions: Only one vehicle key is located in the vehicle, this key has been deactivated and it is positioned on the marking in the storage compartment for the data transfer. The costs for this adaptation are to be borne by the customer. For the newer BR 174, 178, 244, 248, 520, and 540, a software update must be initiated, as there is no way to perform SCN coding.

Dear 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.

Dear Mercedes-Benz Owner: In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA is extending the warranty coverage for the Diagnostic Module for Tank Leakage Detection ("DMTL") on your vehicle from the original New Vehicle Limited Warranty of 4 years / 50,000 miles to 15 years/150,000 miles (whichever occurs first). This applies to the vehicle regardless of ownership. Why the Warranty extension? On certain Model Year 2018 - 2024 A / C / CLA / CLS / E / G / GLA / GLB / GLC / GLE / GLS / GT / S / SL Mercedes-Benz vehicles, under certain circumstances, the DMTL may trigger erroneous Diagnostic Trouble Code ("DTC") entries that may result in the illumination of the Check Engine Malfunction Indicator Lamp ("MIL"). Any repairs under this warranty extension must be performed by an authorized Mercedes-Benz dealership. • If your preferred authorized Mercedes-Benz dealership performs a diagnosis and confirms that your vehicle has the issue, the repair will be covered under this extended warranty and performed at no cost to you. • This extended warranty does not apply to any other components or conditions beyond the ones mentioned above, and standard warranty terms apply, including the exclusions with respect to extra expenses, as identified in the Service and Warranty Information booklet.