2021 Mercedes-Benz GLS580

The vehicle suffered a sudden, catastrophic 48V mild-hybrid electrical power supply breakdown and complete system failure while traveling at highway speeds during a cross-country move. The sudden failure forced an emergency lane change into an isolation zone just off the highway. The sudden failure left the cabin completely powerless with no operational safety systems, hazard lights, or air conditioning in extreme 100+ degree heat. This roadside isolation created an immediate physical hazard and directly inflicted acute heat exhaustion and severe dehydration, requiring a subsequent emergency clinical medical evaluation on July 5 for lingering environmental exposure symptoms. Subsequent forensic diagnostics performed at an authorized secondary dealership (Mercedes-Benz of North Scottsdale) captured digital video evidence of active, high-voltage 48V electrical arcing across a completely loose, un-torqued main grounding network connection left by a prior repair facility (Mercedes-Benz of Syracuse) during a major warranty engine removal repair just 7 days prior. Secondary dealer diagnostics officially logged this internal structural failure under factory tracking as Damage Code 5482G388. The loose connection created an active, immediate thermal and fire hazard capable of igniting nearby fuel or fluid lines. The original repairing facility deflected liability, claiming the high-voltage ground studs 'loosen due to many reasons' on an asset with no prior electrical faults. This creates a severe ongoing fire, thermal, and crash risk for this model year's 48V electrical system architecture.

NHTSA ID

11753406

Incident

Jun 30, 2026

The contact owns a 2021 Mercedes-Benz GLS580. The contact stated that after entering the vehicle, the contact became aware of an abnormally strong fuel odor inside the vehicle. There was no warning light illuminated. The vehicle was taken to two independent mechanics who referred the contact to the local dealer for assistance. The local dealer was contacted, but the vehicle was not diagnosed or repaired. The manufacturer was not contacted. The failure mileage was approximately 83,000.

NHTSA ID

11701200

Incident

Nov 16, 2025

Mileage

83,000 mi

Delivered an unfinished or car with a broken part,Seat Problem not locking properly, Electrical Problem, Engine Light Came on, ESP warning, Suspension Problem, Battery Problem, Steering Jerking, Mirror Problem which they said Mercedes Benz aware of it, some sort of sound, car getting hot excessively.

NHTSA ID

11574364

Incident

Nov 24, 2023

Continuous malfunctioning front windshield wipers. In light to medium rain/wet condition the wipers chatter/jump on the windshield, leaving residue on windshield and causing substantial distraction to driving and even discourages use of wipers (leaving visibility poor). Mercedes Dearler/Service center has attempted multiple remedies over time but to no avail. Internet search of multiple forums on the web show many people with similar issues so thought it would be relevant for NHTSA to know. Issue is ongoing.

NHTSA ID

11491095

Incident

Mar 1, 2021

The contact owns a 2021 Mercedes Benz GL550. The contact stated that while driving 30 -35 mph an unknown vehicle crossed her path, the driver depressed the brake pedal but was unable to stop before colliding with a vehicle. The steering wheel air bag split open and deployed. The contact sustained injuries, the inside of her right arm was cut. The air bags on the floor deployed and contact sustained severe burns on her shin medical attention was provided. The contact stated she still has an open wound. The distance warning indicator light was illuminated. There was no reported fire. The police were on the scene however, there was no police report filed. The vehicle was towed to an independent lot. The local dealer was contacted but the vehicle was not diagnosed. The manufacturer was contacted but, no further assistance was provided The failure mileage was approximately 3,000. The contact mentioned the floor air bag was removed by the tow company. The VIN was not available. UPDATES- Due to the impact of the airbags on the floor, it caused major bruising, restricted blood flow and two hematomas to my right shin. In August of 2020 I had major surgery to remove the hematoma and healing for this open wound took seven months. I have a major scar on my right shin. Additionally, I have a scar on the inside of my lower right arm as the airbag on the steering wheel split open and cut my arm. Steigler Automotive Repair, in Reseda, California repaired all damages to my vehicle (approximately $30,000k) and the car was released back to me.

NHTSA ID

11444154

Incident

Jul 3, 2021

Mileage

3,000 mi

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 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.

Complaint Radio station cover art does not refresh when switching stations. The UI continues to show the old station’s artwork instead of updating to the new one. Cause When a new station change request is triggered, a temporary glitch is causing the Head Unit application to fail to overwrite the previous request. This glitch is causing the cover art mismatch in the Radio application. Remedy Please do not replace any parts. Please update the Head unit software to E505.9