2021 Mercedes-Benz AMG C43

The contact owns a 2021 Mercedes-Benz C43 AMG equipped with Continental Tires, Tire Line: Sport Contact, Tire Size: 225/40/R19, DOT Number: LMJAD5UR (Front Tires) and Pirelli Tires, Tire Line: P Zero, Tire Size: 225/40/R19, DOT Number: 93X2Y082 (Rear Tires). The contact stated while driving approximately 70 MPH, the TPMS warning light illuminated. The contact inspected the vehicle and became aware of blisters on the sidewall of the tires. The vehicle was taken to an unknown dealer where the failure was confirmed. The tires were replaced. The manufacturer was not notified of the failure. The approximate failure mileage was 12,000.

NHTSA ID

11517697

Incident

Apr 18, 2022

Mileage

12,000 mi

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’).

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 (205, 463, 253, 190 & 222 platforms) vehicles, the engine control unit software does not correspond to current production specifications. It is therefore possible that on-board diagnostics and/or exhaust gas emissions requirements may not be fulfilled.

Complaint Crackling and cracking noise from the outer wheel on the front axle when cornering Cause The noise is generated by a micromovement on the contact surface between the rim and the brake disk (wheel bolt group) and may be intensified by potential soiling. The more lightweight rim (AMG forged rim) transmits the noise louder; in the case of cast rims, the noise is generally not perceptible. This is not a technical defect, but rather a complaint concerning comfort. Safe operation of the vehicle is ensured at all times. Remedy Important note: The operations described below do not represent a permanent remedy in every case. The noise may reoccur again after an indefinite period of time; sanding the rims with abrasive media multiple times is not permissible. Only cleaning using the Hazet tool 4960-160 (recommendation) can be performed without any concerns each time the wheel is changed or if the complaint reoccurs. Replacing the parts (rim, wheel bolts, wheel bearings, wheel hub, brake disk) is not expedient in the event of this complaint. ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Clean the components of the wheel bolt connection according to the WIS instructions Sand down the rim and brake disk bowl by performing the following steps: • Manually sand rim (old design only) in area of water drain bores (Figure 1; item A), approx. 1.5 cm left and right of water drain bore (Figure 2) Note: Use abrasive paper with grit size 80. The grooving in this area should no longer be visible (sand down approx. 0.1-0.2mm) • Also sand brake disk bowl using emery cloth or abrasive paper with a grain size of 120 • For vehicles equipped with the AMG ceramic brake system (B07), abrasive paper may not be used for cleaning on the brake disk side Note: Do not use any cleaning agent when cleaning on the rim side. Cleaning using abrasive paper with a grain size of 80 will suffice. Do not apply any grease, lubricant or paste after cleaning The brake disk bowl should be "bare metal" in the area of the imprints made by the hole (Figure 3)

Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end). The noise is heard once in each instance when changing direction of travel. Note: Sound file in attachment Cause If the complaint is eliminated by experimentally loosening the outboard collar nut (by 1 turn), the problem is due to cracking of the microweld between the wheel bearing inner race and the joint housing of the side shaft. Note: The collar nut must always be replaced after being loosened. See also LI33.20-P-078406 Remedy Coat contact surface of side shaft with wheel bearing with Molykote paint. To do this, proceed as follows: 1. Remove side shafts 2. Clean contact surface A (see image file in attachment "Outer joint housing before") before coating with Molykote, using "spirit" (free of dust and grease) 3. Coat contact surface A (see image file in attachment "Outer joint housing after") with Molykote and leave to dry for "one hour" in removed condition 4. Reinstall side shafts Note: Before using the antifriction coating (Molykote), stir it or shake it thoroughly for (at least 1 minute).

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, July 9, 2026. After July 9th, 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.

Complaint Service code B1 displayed in the customer menu does not match the workshop code displayed in the workshop menu, e.g., 505 or 550A, which includes a service A. Cause The root cause is currently being investigated. Remedy To determine the cause, the instrument cluster control unit (N133/1) and powertrain control unit (N127) logs are required before confirming the service or correction using XENTRY Diagnosis. Please open a TIPS case to BCE inbox with the requested information in the attachments.