2022 Mercedes-Benz AMG GLC63S

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.

Complaint Oil leaks found on M176 or M177 engines diagnosed to be from the cylinder head cover area Cause Unknown (under investigation) Remedy If oil leaks are found at left or right cylinder head cover area please collect the following information and open TIPS case. 1. Collect photos of the leak 2. Include close up and wide view photos to accurately represent the location 3. Include if the vehicle has a "check oil level" Light on in the cluster or fault codes 4. Check oil level as per WIS to verify level and calculate possible oil loss from the leak 5. Identify and communicate the severity of the leak and provide supporting documentation 6. Open a TIPS case with the above information and submit to the Powertrain team for processing

Complaint Clanking noise from the area of the speakers in the doors. Cause Under analysis. Remedy To narrow down the cause, first of all remove the door trim. • If the noise continues to occur even with the door trim removed, then continue the diagnosis working towards the speaker and if necessary, create a TIPS case with an informative video as an attachment. Information: Please refer to this document in the warranty claim and, after completing diagnosis, select the damage code corresponding to the component part that caused the problem. • If the noise stops when the door trim is removed, please proceed in accordance with LI72.10-P-067691. Information: In this case, do not use a damage code for the speakers in the warranty claim!

Complaint This document is intended as a pre-case diagnostic reference for transmission related concerns. It will also ensure that if a case is necessary, all supporting documentation is available. This should not be used on its own as justification for creating a TIPS case. Cause The root cause will vary depending on the complaint. The goal of this document is to provide diagnostic checks and procedures that may help resolve customer complaints without opening a TIPS case. Remedy Before opening a transmission-related TIPS case, the following steps must be performed to ensure all relevant data has been collected and possible remedies (when applicable) have been performed. Please Note: At minimum, the documents below must be collected before proceeding to ensure the data in its original state when the vehicle arrived is captured. - Initial Quick Test w/ Freeze frame data - VGS Control Unit Log - Initial EEPROM data (.txt format) - IPR Result (if applicable. See LI27.00-P-073124 - Transmission diagnosis using the Intelligent Predictive Repair (IPR) tool) - Transmission Heath Page If the vehicle has previously been repaired for the same concern, note the date, mileage, and TIPS case or RO number, along with a brief description of the prior work performed. IPR Guidance: The IPR recommended repair should be completed prior to following any steps in this LI and prior to case creation. IPR repairs do not require additional warranty approvals or a TIPS case to validate/confirm the results. To ensure efficient case handling, please avoid opening TIPS cases for this reason. For further information regarding IPR please see the following documents: LI27.00-P-073124 - Transmission diagnosis using the Intelligent Predictive Repair (IPR) tool Oil Pan Condition Evaluation: In some situations, IPR will advise checking the oil pan condition and determining a repair based on the evaluation. Example photos in Xentry can be found in two ways: • Use the blue hyperlink in the IPR result, and it will take you to the Condition check of transmission oil • Navigate to Xentry Bluebook > Help for control unit > Condition check of transmission oil If a different repair that what is recommended by IPR is performed, attaching photo documentation of the complaint vehicle oil pan and the IPR example to the claim is required. Reproducing the Concern: Proper evaluation of transmission concerns generally requires the condition to be reproducible. It is recommended to compare the vehicle to a similar model, if available, to help determine whether the shift behavior is characteristic of the drivetrain or uncharacteristic for the vehicle. If the concern cannot be duplicated: • A test drive with the customer may assist in understanding and reproducing the complaint. • The vehicle shift quality should be compared to a known-good vehicle with identical drivetrain and model year. • Check Shift Quality History (VGS Control Unit > Adaptations > Shift Quality History) Shift Quality History will show the last 5 noticeable harsh shifts and some of the parameters in which it occurred. You can use this to attempt recreation of the operating conditions and increase likelihood of reproducing the complaint. Complaint A: Shift Quality Note: Certain AMG variants may exhibit more firm and noticeable shift behavior as a normal characteristic. Refer to LI27.60‑P‑075147 for additional information. 1. Perform Valve flushing procedure 2. Perform 5 Torque Converter adaptions in a row - Allow the vehicle to warm up naturally, DO NOT power brake as it will increase the temperature in the torque converter. - After the 5th adaptation, collect a screen shot showing all 5 on one page 3. Perform a standstill adaption - collect a screen shot Recheck vehicle operation. If the concern has not improved, driving adaptations should be performed to target specific gear shifts.

Complaint Mercedes-Benz USA is currently experiencing limited availability of transmission fluid specification ATF 236.17 due to a global supply constraint. 236.17 ATF 1L and 5L (PNs: A002989060312 and A002989060313) bottles are out of stock or in limited supply at Zep. This LI has been created with the following intention: - Provide dealers with additional workshop-focused guidance regarding the current ATF 236.17 supply constraint and the planned introduction of ATF 236.18. - Supplement existing communications and address common workshop questions related to maintenance, repairs, and fluid applicability. - Provide technical clarification and practical workshop guidance during the temporary supply constraint period. Dealers should continue to reference the latest News Channel Updates (NCUs) for the most current information regarding availability, ordering processes, supply status, and other related updates. Cause Damage to the Shell production facility has resulted in 236.17 oil supply being reduced to 50% of normal output until the end of 2026. Remedy Please first check Latest NCU updates for latest detailed information. Please continue placing orders through Paragon as normal. Supply is expected to remain reduced and allocation measures are currently in place. We ask for your patience through this restricted supply period. Most orders will be filled in the order in which they were received, as supply is replenished. Those dealers with zero inventory, and pending orders, will receive priority. We expect supply to be stabilized in September 2026. Approved Fluids: Only use transmission fluid from the approved list found on the Mercedes-Benz Operating Fluids website. Non-approved fluid will result in mechanical damage to the transmission and must be avoided. https://operatingfluids.mercedes-benz.com/sheet/236.17 Approved fluids can be claimed as follows if there is no Mercedes-Benz part number: Part # ATFSUB1L - TRANSMISSION FLUID 1 LITER ATFSUB5L - TRANSMISSION FLUID 5 LITER Dealerships with Zero Inventory AND Grounded Vehicles: If a vehicle is currently grounded for repair at your dealer due to no 236.17 inventory, we may be able to expedite your order. Please open a StarSupport ticket including the following information: (Parts Related Inquiry>National Accounts>Zep) • LI document number • Short explanation of repair needed for grounded vehicle • Current days down of RO Maintenance and Service Interval Guidance Published maintenance intervals remain unchanged. Vehicles should continue to be maintained in accordance with the applicable maintenance schedule. This LI does not revise or extend any published maintenance interval requirements. If all required parts and materials are not available prior to scheduling or beginning a transmission service, dealers should consider postponing routine preventative transmission maintenance until the necessary parts become available. For vehicles that have not yet reached the applicable maintenance interval and do not exhibit transmission-related concerns, there is no need to recommend preventative transmission services prior to the scheduled maintenance interval. When evaluating whether routine transmission maintenance can be deferred until parts become available, dealers should consider: • Overall vehicle condition • Vehicle usage and operating conditions • Presence of transmission-related symptoms or customer complaints • Customer expectations and vehicle operating requirements • Availability of required parts and materials Introduction of New Fluid Specification 236.18 Mercedes-Benz is currently preparing the introduction of ATF 236.18 as an additional approved transmission fluid solution for applicable NAG3 transmissions. At the time of publication of this LI, ATF 236.18 is not yet available for dealer ordering or workshop use in the U.S. market. See attachment for further details.

This NCU replaces the prior NCU issued on May 15, 2025, and contains additional MY 2023 and MY 2024 vehicles which are highlighted below. In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA, LLC (“MBUSA”) is extending the warranty coverage on the Diagnostic Module for Tank Leakage detection (DMTL) in certain Model Year (“MY”) vehicles listed below from the original New Vehicle Limited Warranty of 4 years/50,000 miles to 10 years/120,000 miles (vehicles certified as LEV II) and 15 years/150,000 miles (vehicles certified as LEV III), whichever occurs first, for the following condition: •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’).