2020 Mercedes-Benz GLS450

AMENDMENT TO ACTIVE CASE 11723015. CRITICAL AIRBAG & SAFETY DEFECTS. This files a safety defect amendment to open case 11723015. Diagnostic scans confirm central data bus network collapse on VIN [XXX] has migrated into safety-critical occupant restraint and visibility modules, violating 49 U.S.C. § 30118. I. AIRBAG & RESTRAINT HAZARDS Scans from [XXX], document active faults: DTC U042782: "Implausible data received from Electronic Ignition Lock." The SRS module receives corrupted data from the failed ignition gateway, creating risk of airbag non-deployment. DTC B007A13: Passenger seatbelt pre-tensioner open circuit; occupants are unprotected against crash displacement. DTC B11FA4B: Active "Overtemperature" faults in heating elements indicate localized thermal short-circuit risk. II. HARDWARE DECAY Physical teardown confirmed structural oxidation on the central gateway motherboard and corroded connector pins. Modular swaps failed; network lock code U016887 returned within 8 months. Raw dealer records are available for federal inspection. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11741714

Incident

Mar 18, 2026

The contact owns a 2020 Mercedes Benz GLS. The contact stated that while driving on the highway, the rear door window trim bars on the passenger side detached from the window. The vehicle was taken to the dealer where they diagnosed as a rear door window trim detachment however the vehicle was not repaired. The manufacturer was not notified of the issue. The approximate failure mileage 65,000.

NHTSA ID

11738177

Incident

Apr 22, 2026

Mileage

65,000 mi

Window trim on the passenger rear window fell off while driving- it put others at risk by flying off the vehicle on the interstate- Mercedes Benz of Omaha quoted replacement of the window trim parts- no warning messages on dash

NHTSA ID

11738164

Incident

Apr 15, 2026

The engine wiring harness insulation near the ignition coil connectors prematurely deteriorated due to prolonged exposure to engine heat in the turbocharger/exhaust area. Multiple wiring connectors exhibited brittle, cracked insulation with exposed conductors. The degraded wiring began shorting within the ignition system, causing engine misfires, ignition circuit faults, and eventual loss of engine operation. While being operated by a rental customer the vehicle developed severe misfires followed by electrical shorting, smoke, localized flames in the engine harness area, and eventual engine shutdown. The flames self-extinguished after the electrical shorting stopped, but portions of the harness insulation showed thermal damage and overheating. The customer became stranded due to the vehicle becoming inoperable. Diagnostic faults included ignition coil circuit open faults and ignition primary circuit faults. The vehicle ultimately became inoperable due to the electrical failure. Inspection revealed multiple adjacent ignition harness connectors showing progressive heat-related insulation degradation in the same high-temperature area, indicating a broader harness material failure rather than isolated damage. This failure occurred on a 5-year-old vehicle. Engine wiring harness insulation should not prematurely degrade and short under normal operating conditions.

NHTSA ID

11736819

Incident

Apr 28, 2026

On a sunny afternoon without zero clouds in the sky, 75 degrees I was driving at 35 mph on a two-lane road with no cars in front of me, behind me, or coming in the other direction, the brakes were urgently and automatically applied and the seat belts dramatically tightened. The system showed a large red X on the screen. It was obvious the automated safety system mistakenly thought we were about to crash into something but there wasn't anything but smooth asphalt.

NHTSA ID

11726166

Incident

Mar 22, 2026

The vehicle (2020 GLS 450) suffers from terminal infrastructure "Electronic Rot," resulting in a consistent Breach of FMVSS 111 (Rearview Visibility) and dangerous Automatic Emergency Braking hallucinations. On 03/08/2026, a routine car wash triggered multiple system failures, including "Camera View Restricted" and "Adaptive Highbeam Assist Currently Unavailable," proving the electrical architecture is compromised by minor moisture. This is a multi-dealer failure: the vehicle was sold as "Certified Pre-Owned" by Mercedes-Benz of Fredericksburg with undisclosed active "Special Procurement" status; a 200-day attempted EIS remediation at i.g. Burton failed to resolve the hazards; and the regular service center, Mercedes-Benz of Annapolis, has failed to remediate the ongoing "Electronic Rot." All parties are currently withholding machine-level XENTRY diagnostic sequences required to verify the vehicle's safety status.

NHTSA ID

11723015

Incident

Mar 8, 2026

The vehicle is experiencing deterioration of the main engine wiring harness insulation, resulting in exposed wires contacting each other. This condition has caused intermittent check engine lights and electrical fault codes. The dealership has confirmed that the wiring insulation has degraded, allowing wires to contact each other. The issue appears related to material durability of the harness rather than external damage. The concern is that continued deterioration could result in: •Sudden engine misfire •Loss of power while driving •Engine stalling •Potential electrical short circuit An unexpected loss of engine power at highway speeds could increase the risk of a crash. The dealership indicated that similar harness insulation concerns have been observed on other M256-equipped vehicles. This appears to be a potential safety-related defect involving engine wiring insulation durability.

NHTSA ID

11719907

Incident

Dec 14, 2025

The sunroof spontaneously shattered while driving down the interstate. No other cars involved and no rocks or debris caused it. It was inspected and repaired at a Mercedes dealer, however, Mercedes refused to cover the repair under the pre-owned certified warranty. We had to file an insurance claim. In doing research, it appears this is a common and ongoing problem with various models of Mercedes.

NHTSA ID

11658502

Incident

Apr 20, 2025

Complaint Customer concern of Air Conditioning not cooling. *NOTE ‑ Use of tracer DYE for leak checks is not approved. Only approved leak check procedures as per WIS are approved. Cause Possible refrigerant leak. Remedy Perform the following measures : *Important* ‑ Photo documentation requirement is no longer in effect as of 10/1/2025. Remedy 1: Replace Evaporator (Only applies to vehicles produced PRIOR to April 15, 2022 and has NOT had the evaporator replaced previously) 1. Ensure that the rest of the AC system has been thoroughly checked for leaks with forming gas as per WIS before condemning the evaporator. 2. If no other leaks are found, replace the evaporator 3. *Important* ‑ when you get the new evaporator, check the expansion valve bracket to see if there are any bends (see attachment "Bent Bracket"). a. If bent, remove the expansion valve and bracket and check for damage to the flange (see attachment "Flange Damage"). i. If damage is found, order another evaporator and claim the part under parts warranty. The warranty claim MUST include a photo of the damage found. ii. If no damage is found, flip the bracket and torque to 7Nm. Check the evaporator for proper sealing before fully installing. b. If no bends are found, the evaporator should be installed in the vehicle. Note ‑ *If the evaporator housing has been opened or the evaporator or housing has been tampered with, the claim will be debited. Remedy 2: (Applies to all vehicles produced on or AFTER April 15, 2022 up to August 1, 2025) 1. Ensure that the entire AC system has been thoroughly checked for leaks with forming gas as per WIS . 2. If no leaks were found AND the system came in with no cooling/low charge, OR the evaporator is suspected of leaking: 3. Replace ONLY the expansion valve bracket, seals, and bolts as supplied in kit A 167 832 47 00, in accordance with the procedure outlined in WIS document AR83.30‑P‑5520ME. 4. IF THE PRODUCTION DATE IS BETWEEN JUNE 1, 2023 AND JULY 1, 2024, REPLACE THE DRYER AS WELL. (NOT THE CONDENSER) 5. After, charge the system and perform a few drive cycles. 6. Recheck the vehicle for leaks. 7. If no leaks are found, the vehicle can be released. 8. If a minor leak is detected that is less than 50ppm, then perform the following steps: • If a leak is detected, fill the system with forming gas • Close all doors and windows for 10 minutes. • Vehicle off with no blower activation. • Open the driver's door and measure ppm detection as soon as the door is open and the sniffer goes into the vehicle. • If no leaks are measured, fill the system and release. • If you still feel the evaporator is needed/leaks are still detected, a TIPS case is required for replacement. Provide all documentation listed in Remedy 3. Remedy 3: (Only applies to vehicles produced AFTER August 1, 2025) Ensure that the entire AC system has been thoroughly checked for leaks with forming gas as per WIS . If no leaks are found or the expansion valve has been found to be leaking, remove the expansion valve and check the bracket. If the bracket is bent, replace the expansion valve bracket, seals, and bolts as supplied in kit A 167 832 47 00. In the warranty submission, include photos of both sides of the bracket and a side profile so it can be seen that the bracket is bent. If the bracket is NOT bent or leaks from other locations are found, then open a TIPS case with the following: 1. Initial Quick Test 2. Create a short video of the actual pressures via AC machine, showing the engine running, and hold a copy of the VIN/RO in view as well. 3. OBS recording of XENTRY AC actual values of compressor request to be on and current value. (Instructions in Attachments) 4. Video recording of the leak being found via sniffer at the R/F AC drain after removing the under dash panel if the evaporator is suspected. (see attached videos) 5. If the evaporator is found to be leaking via sniffer, another video needs to be uploaded (or a continuation if only making the video after checks

Complaint Customer complaints relating to automatic transmission 725.0 (NAG3 Classic /9G‑TRONIC automatic transmission) and 725.1 (NAG3 facelift/9G‑TRONIC automatic transmission facelift) For faster, more effective and more targeted diagnosis, Intelligent Predictive Repair (IPR) has been developed and integrated into XENTRY Diagnosis. This ensures an automated diagnosis process. Cause As part of the on‑going quality monitoring process and associated quality and damaged part appraisals, a high number of ineffective repairs have been discovered. Such ineffective repairs have a negative impact on all those involved. For the customer, it means high costs and long repair times and for the dealer, it may result in the warranty claim being rejected. Remedy General note: IPR is available for: ‑ NAG3 Classic (automatic transmission 725.0) ‑ NAG3 Classic ‑ AMG sport model (AMG 43 and AMG 53 with converter, automatic transmission 725.0) ‑ NAG3 Classic ‑ Hybrid (automatic transmission 725.0) ‑ NAG3 Classic ‑ AMG 63 (automatic transmission 725.0) ‑ NAG3 MOPF ISG2 (automatic transmission 725.1) ‑ NAG3 MOPF Hybrid (automatic transmission 725.1) ‑ NAG3 MOPF AMG sport model (AMG 53/AMG 53e with ISG48V2 & converter /hybrid, automatic transmission 725.1) ‑ NAG3 MOPF AMG 43/63 with engine 139/177 (automatic transmission 725.1) Steps for the Service Advisor: Important: The more information and detail that can be given to the workshop about the complaint, then the more effective the subsequent diagnosis with IPR can be. To this end, a detailed service reception questionnaire has been provided to help the Service Advisor ask the right questions about the complaint. ‑ Ask precise details about the customer complaint and the conditions and context. ‑ Fill out the service reception questionnaire (please see WIS document: OF27.00‑P‑3000‑05A) for customer complaints in detail and forward it to the workshop. Operation steps for the workshop employee: 1. Perform quick test 2. Access the transmission control unit via XENTRY Diagnosis 3. Select "A customer complaint has been received" and carry out all subsequent operation steps (IPR diagnosis path). 4. The IPR repair instructions are displayed, Carry out the IPR repair instructions without performing any further diagnostic or repair steps. ‑ Important: The IPR repair instructions are binding and must be carried out. Differing repairs are possible; such repairs must be documented in XENTRY in free text. Please observe the information regarding the IPR diagnosis process in XENTRY. Conventional diagnosis and subsequent appropriate repairs are only permitted if IPR does not specify any repair instructions. Invoicing for the guided IPR steps: Operation item 27‑0640 and 0.1 hours Notice regarding warranty: The use of IPR in association with warranty claims is mandatory! If the IPR repair instructions are disregarded without justification, the warranty claims may be rejected and/or are subject to debit. IPR will provide a measure to repair the vehicle based on various data sources (EEPROM, fault codes, etc). Please consider the vehicle maintenance record of the vehicle. For warranty and goodwill repairs, the transmission ECU test log and/or IPR test result must be uploaded into Paperless XENTRY Diagnosis (pXD) . If repair is being determined based of oil pan condition pictures of oil pan MUST be provided to warranty as justification. ·Tamper‑proof documentation: The IPR repair instructions are stored in the control unit log. Please file this document in a tamperproof manner ‑ either in digital form or as a hard‑copy printout and also enclose a printout with the damaged part. In this regard, please comply with the country‑specific warranty requirements of the MPC/general distributor.

Complaint Sporadic warning message in instrument cluster "Engine oil pressure, stop switch off vehicle" (or similar) is shown in red on vehicles with low mileage. Cause Directional control valve may stick. Remedy 1‑ Read off oil level in instrument cluster and correct if necessary. 2‑ Perform approx. 10‑15 engine starts, then clear fault codes. 3‑ Perform road test with vehicle. If fault code reoccurs during road test: Install new directional control valve.

Complaint Slight creaking noises when steering. Cause Noises may come from one or more sleeves of the horn contact plate. Remedy Remove the horn contact plate and check the sleeves for noise; see attached video. If necessary, apply lubricant to the sleeves.

Complaint Repeat workshop visit for vehicle vibration while braking from 60MPH. NOTE: Although the symptom is similar to a tire or wheel vibration, it is usually readily noticeable that it is distinctly different if it happens at all times or only while braking. Cause Although the cause of the vibration is most likely due to excessive lateral runout on the rotor or hub/wheel bearing, the system as a whole needs to be checked for other possible contributors. 1. Prior collision damage. 2. Excessive vehicle sitting times without rotating components. 3. Wheel bearing/hub lateral runout. 4. Wheel mating interface has been overtightened (did not follow WIS torque procedures). 5. Mating interfaces have been excessively modified (painted, gouged, bent, etc...). Remedy Read through the entire attached worksheet prior to performing. After performing, please review the final page and perform work accordingly. NOTE: This document is not pre‑authorization or otherwise dealing with warranty. This is intended for diagnostic purposes only. If there are any questions on how to proceed OR The work sheet has been performed and the vehicle has returned with the same concern. Please perform the measurements as seen in the worksheet again and open a TIPS case to the Body, Chassis, and Entertainment team.

Complaint Red coolant warning in instrument cluster. Fault codes U019F00 or U019F87 current/stored in MRG1 control unit. Cause Various causes Remedy Perform guided test for fault code U019F with XENTRY diagnosis. Verify the following connections are clean and tight. Correct any problems and retest pump actuation: ‑12V plug at M75/11 ‑48V plug at M75/11 ‑48V connector X192/4 ‑Connections at 48V fuse box F153/2 ‑Sockets 1,2, and 5 at connector 2 of MRG1 control unit ‑M75/11 circuit 41 ground If actuation and above connections are OK, but resistance between M75/11 and engine block is less than 2 ohms or heat shield touching coolant pump, proceed with below steps. 1‑Modify engine insulation per attached instructions. 2‑Remove engine control module and measure continuity within control unit between connector 2 pin 1 and connector 6 pin 2. 2a‑If open circuit is found, replace engine control unit (MRG1) and perform initial startup. Refer to XENTRY parts information group 54/054 item 300. 3‑Clear faults and verify M75/11 operating normally.