2021 Mercedes-Benz AMG E53

Was driving the car when it gave me a -48v malfunction. This was quickly followed by an overheat warning to turn the car off. It appears to be an issue with the -48v battery. Still waiting to hear what root cause is as MBUSA has had the car for 24 days and counting without many answers.

NHTSA ID

11534064

Incident

Jun 30, 2023

What component or system failed or malfunctioned, and is it available for inspection upon request? Automatic Emergency Braking / Selt Belt Pretensioner. Car can be inspected at dealer during a scheduled service if needed. How was your safety or the safety of others put at risk? I was driving on a local road (paved, no painted road markings, some small cracks/pot holes but all minor) that I frequently drive without issue. This time as I was coming out of a minor left-hand curve and about 30 meters from a slightly sharper right hand turn the Automatic Emergency Braking warning light activated, as well as the warning alarm, and the Seal Belt Pretensioner engaged and yanked me (driving) back (as it would if the vehicle was preparing for a collision. However, the vehicle never activated the brakes to slow the vehicle and the warning light and alarm deactivated and the seat belt released the tension. There were no vehicles coming from the other direction, no animals or pedestrians in sight. There is a utility pole located about 2-3ft off the right side of the road near this area. I've now had this occur two more times (three total) in the same location driving in the same direction. Twice I was the only occupant, and once there were two occupants, one in the driver's seat and one in the passenger seat (the Seat Belt Pretensioner activated for both occupants). Safety Issue: Automatic Emergency Braking System activating unexpectedly and unnecessarily. When Automatic Emergency Braking System is activated the Seat Belt Pretensioner activates and forcefully restrains the occupant (as I assume it should the vehicle expects a collision or harsh braking). This is very surprising and distracting for the driver (and in one instance also a passenger, who afterwards said they remarked they felt like it almost gave them a heart attack). This can lead to an accident given the unexpectedness. Additionally, the brakes never engaged or slowed the vehicle in any of the three instances.

NHTSA ID

11497646

Incident

Jun 2, 2022

The doors are very Heavy and it is difficult to get it to stay open. Additionally if the car is on a slight uphill and the door is fully open, the door tends to start closing and is not held in place-it becomes very dangerous if you are stating to get out of the car.The door is so heavy that a leg can get caught and broken I have advise Mercedes of this problem but they tell me that the tension is not adjustable It is very dangerous getting both in and out even wee on a flat surface and much more dangerous on the slighted of inclines

NHTSA ID

11462896

Incident

Apr 1, 2022

Car displays blank screen when transmission is placed in reverse with the words in RED: "System Inoperative".

NHTSA ID

11431562

Incident

Sep 2, 2021

WHILE GOING 45 MPH ON A CLEAR FOUR LANE SMOOTH BLACKTOP CITY STREET THE CAR CAME TO A COMPLETE EMERGENCY STOP. A RED TRIANGLE APPEARED ON THE DASH BUT BECAUSE OF THE STARTLING NATURE I COULD NOT REMEMBER EXACTLY WHERE. THERE WAS NO APPARENT REASON FOR THIS EMERGENCY STOP, THIS STREET WAS FAMILIAR AND HAD BEEN DRIVEN DAILY FOR OVER THIRTY YEARS. IF THIS HAD HAPPENED ON THE FREEWAY AT FREEWAY SPEEDS THIS COULD HAVE BEEN A DISASTER.

NHTSA ID

11373428

Incident

Nov 4, 2020

Mileage

90 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’).

Complaint Hand detection system – malfunction / vehicles with code 266 Fault message in instrument cluster: "Active Emergency Stop Assist not available" "Active Lane Keeping Assist not available" "Active steering assist not available" Cause Possible causes: Hand detection mat, hand detection control unit, contacts, and electrical feed line. Remedy In the event of a customer complaint and fault code in IDC control unit: U186B29 in IDC223 or fault code U0429E0, U042941, U042929, U042902, U0429E1 in IDC213 or fault code in HOSWD control unit: B1E7614 Check: Please do not replace the HOSWD control unit. Please flash the new SW and perform the SCN coding for the HOSWD control unit (N179/1) (available from July 2026). The software can be flashed onto all HOSWD213 with HW number A0009011522 and all HOSWD223 with HW number A0009011422. Please also flash the SW for the IDC control unit (N62/4), if possible (only applies to HOSWD223). Erase fault memory Remedy: Turn on the ignition or start the engine without touching the steering wheel. If, after 10 seconds without touching the steering wheel, one of the three fault messages appears on the instrument cluster: Check the contacts and feed lines in the steering wheel by means of a visual inspection for damage, crimp connections, loose connections, etc. (example in picture 2 and 3). If there is visible damage -> replace the steering wheel electronics or the feed lines. If there is not any visible damage -> replace the steering wheel rim. If a yellow message does not appear on the instrument cluster within 10 seconds: Grasp the steering wheel fully with both hands, including the chrome molding at the 6 o'clock position (see picture 1). If the fault is triggered by grasping the steering wheel rim or pressing the clip at the 6 o'clock position, check the contacts and feed lines in the steering wheel by means of a visual inspection for damage, kinked connections, loose connections, etc. (example in picture 2 and 3). Check the ground connections (screw connections and cables to the steering wheel rim); if necessary, retighten the screws/bolts and check for corrosion (picture 4). If there is visible damage -> replace the steering wheel electronics or the feed lines. If there is not any visible damage: Replace the steering wheel rim. Please do not replace the HOSWD control unit. A TIPS case should be created if fault profile is unclear. In the event of a customer complaint and a further fault code in HOSWD: B1E7713: Check the ground connections (screw connections and cables to the steering wheel rim); if necessary, retighten the screws/bolts and check for corrosion (picture 4). B1F1F04: Check the control unit of the hand detection system; if necessary, replace this with the control unit from a donor vehicle (make sure that the hardware part numbers are identical).

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).

Complaint Creaking noise, in irregular sequence when driving slowly in combination with slight steering movements and/or Creaking/crackling noises from the area of the wheel bearing on the front axle when cornering/ maneuvering. Sound file attached for comparison. MUST match noise for proper diagnosis. NOTE: Steering functionality is not affected. Cause Contact area between wheel bearing and steering knuckle. See also: LI35.30-P-058566 (Throttle Lift-Off Noise - Rear) LI33.30-P-056665 (Throttle Lift-Off Noise - Front) LI40.10-P-059248 (Wheel cracking noise when cornering) Remedy 1. Perform Operation A and evaluate by testing vehicle. 2. If noise is still present after re-testing: • If 192/232 chassis, verify FIN is in the listed range below in "Operation B" and perform. • If not 192/232 chassis or vehicle is a 192/232 not in the listed FIN range, additional verifications of where the noise is coming from are needed. Use multiple channel NVH method to narrow down location. Verify the LI's listed above were completed or if there are other similar noises associated with the chassis (Example: 192/232 also has under panel noises and an associated LI). Operation A: 1. Clean contact surfaces of wheel bearing and steering knuckle with brake cleaner (see areas marked blue in pictures "2.jpg" and "3.jpg"). NOTE: The front area of the wheel bearing and the seals must not come into contact with the cleaner, otherwise, the sealing rings will be damaged. 2. Clean threads of wheel bearing mounting. 3. Thinly coat contact surfaces of wheel bearing, steering knuckle, and axle mating face with Molykote (annular joint grease) (see areas marked blue in pictures "2.jpg" and "3.jpg"). NOTE: Axle mating face greasing is also covered in LI35.30-P-058566 and LI33.30-P-056665. Operation B (Only applies to 192 and 232 in listed FIN range): Only affects vehicles up to FIN end number: • Model series 192: xxx xxx xx 002 876 • Model series 232: xxx xxx xx 022 312 1. Replace steering knuckle. 2. Wheel bearings do not need to be replaced.

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.