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Service bulletins for the 2021 Mercedes-Benz AMG GT

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

244 on file from NHTSA, as of 2026-10-19.

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Bulletins, newest first
LI88.60-P-0720932025-01-29. Service bulletin. STRUCTURE:BODY. Complaint Fuel door may require several attempts to open. Please note that if the complaint "Fuel filler flap not opening" occurs, it is important to check the fuel filler flap before replacing the central locking actuator. For gasoline hybrid vehicles where the fuel filler flap fails to open or does so but slowly, observe the document "Fuel filler flap fails to open or does so but slowly on plug-in HYBRID gasoline vehicles"! Cause Central locking actuator may have an electrical fault and may not open. Remedy 1. Car locked: To rule out incorrect operation, operate the fuel filler flap in the area shown in Fig. 1 and listen out for the clicking noise of the microswitch in the central locking actuator. If no clicking can be heard, continue with point 4. 2. Car unlocked: Press area on flap to start the microswitch clicking. Flap opens - show the customer the area to press. 3. Car unlocked: Flap cannot be opened regardless of which area you press. Open the flap by operating the emergency release for the CL actuator (through trunk, fender gap cover, etc, depending on specific vehicle) 4. Central locking actuator pressed directly, no clicking of microswitch, no electrical release of central locking actuator => Clicking of microswitch, electrical release of central locking actuator => Tank filler recess/charging recess not OK; report results via a TIPS case to B/C/E Inbox. 5. Replace central locking actuator; check function of new part before installing it: Do not dispose of damaged part. New central locking actuator does not release: More detailed examination of connector coupling, wiring harness, electrics required.
LI63.20-P-0690562025-01-29. Service bulletin. STRUCTURE:BODY. Complaint Noise from windshield (WSS) or A-pillar at left area at speeds between 110 - 140 mph (see "Complaint area" attachment).
LI07.61-P-0707072025-01-28. Service bulletin. ENGINE. Complaint The customer complains of a check engine light (CEL) on. May also complain of the engine running roughly and/or a loss of power. Cause Multiple Causes Remedy Please see the document "Remedy Instructions" in attachments. For MY19-24 G63 there may be an alternate solution available, please reference LI07.61-P-076755 before performing the steps in this LI for MY19-24 G63 vehicles.
LI42.10-P-0635022025-01-24. Service bulletin. SERVICE BRAKES. Complaint Noises/ squealing from the service brake in various driving situations and ambient conditions. Cause Frictional vibrations Remedy AMG brake systems are designed for high loads. This can result in noises under certain operating conditions and driving styles. Please refer to the Operator's Manual for further information such as care and maintenance instructions (washing vehicle directly after heavy use and using approved cleaning agents). These are dependent on speed, brake pressure or ambient conditions such as temperature and air humidity. 1. Beginning Diagnostics: a) Check whether, apart from this document, an additional document exists for the model series in question, and if so, work through it and then continue with1b. b) Check whether the complaint can be reproduced and at which axle or side the noises occur (ideally together with the customer while driving). c) Check the affected system for component wear, mechanical damage or localized overheating damage. 1. Replace damaged components as necessary and re-assess noise concern. d) Secure vehicle on a lift. 1. Start the engine and depress the brake pedal 3-4 times. 2. Check each wheel to see if they turn freely by hand. 3. If a wheel is not turning freely by hand, this needs to be addressed prior to re-assessing the noise concern. e) Assess condition of brake rotors and pads per WIS and visually (i.e. long periods of stagnation, etc...). 2. Specific Axle Work: NOTE: If brake pad has a metal backing plate, there is no need to affix the adhesive film. a) If the noises are coming from the front axle => Affix linings with adhesive film (see attachments for front axle). If backing plate is installed on pads, move to step 3. 1. Remove brake linings of front axle. 2. Clean all contact points on brake lining and brake caliper/carrier. 3. Clean bonding surface (where pistons contact back of brake pad). Apply adhesive film to the backplate of the piston-side brake lining. For 6 piston calipers, only in the area of the center piston. For other piston caliper configurations less than 6, apply where the piston(s) makes contact with the back of the pad. 4. After installing the brake linings, actuate the brake for 30 seconds. b) If the noises are coming from the rear axle => Affix linings with adhesive film and grease the lining as per the specification (see attachments for rear axle). 1. Remove brake pads of rear axle. 2. Cleaning all contact points on brake lining and brake caliper/carrier. 3. Grease contact points (red areas) between brake lining and guide of brake caliper with heat-resistant lubricating paste. 4. Clean bonding surface (where pistons contact back of brake pad). Apply adhesive film to the backplate of the piston-side brake lining. IMPORTANT: Be absolutely certain to not allow paste between friction surfaces of the pad and disc! 3. Brake Bedding Process: a) Before trip, the mileage incurred must be clarified with the customer (approx. 30 miles). b) Select a suitable route so speeds of approximately 65 MPH can be achieved. c) Brake the vehicle 15 times with a brake pressure of approx. 30 bar (have the passenger read it out using XENTRY) from 62 MPH to 30 MPH (no emergency stops and no braking in the ESP control range). Maintain a cooling distance of approx. 1 mile between brake applications. d) Finally drive approx. 3 miles to allow the system to cool. e) Reassess noise.
LI42.10-P-0635022025-01-16. Service bulletin. SERVICE BRAKES. Complaint Noises/ squealing from the service brake in various driving situations and ambient conditions. Cause Frictional vibrations Remedy AMG brake systems are designed for high loads. This can result in noises under certain operating conditions and driving styles. Please refer to the Operator's Manual for further information such as care and maintenance instructions (washing vehicle directly after heavy use and using approved cleaning agents). These are dependent on speed, brake pressure or ambient conditions such as temperature and air humidity. 1. Beginning Diagnostics: a) Check whether, apart from this document, an additional document exists for the model series in question, and if so, work through it. b) Check whether the complaint can be reproduced and at which axle or side the noises occur (ideally together with the customer while driving). c) Check the affected system for component wear, mechanical damage or localized overheating damage. 1. Replace damaged components as necessary and re-assess noise concern. d) Secure vehicle on a lift. 1. Start the engine and depress the brake pedal 3-4 times. 2. Check each wheel to see if they turn freely by hand. 3. If a wheel is not turning freely by hand, this needs to be addressed prior to re-assessing the noise concern. e) Assess condition of brake rotors and pads per WIS and visually (i.e. long periods of stagnation, etc...). 2. Specific Axle Work: a) If the noises are coming from the front axle => Affix linings with adhesive film (see attachments for front axle). 1. Remove brake linings of front axle. 2. Clean all contact points on brake lining and brake caliper/carrier. 3. Clean bonding surface (where pistons contact back of brake pad). Apply adhesive film to the backplate of the piston-side brake lining. For 6 piston calipers, only in the area of the center piston. For other piston caliper configurations less than 6, apply where the piston(s) makes contact with the back of the pad. 4. After installing the brake linings, actuate the brake for 30 seconds. b) If the noises are coming from the rear axle => Affix linings with adhesive film and grease the lining as per the specification (see attachments for rear axle). 1. Remove brake pads of rear axle. 2. Cleaning all contact points on brake lining and brake caliper/carrier. 3. Grease contact points (red areas) between brake lining and guide of brake caliper with heat-resistant lubricating paste. 4. Clean bonding surface (where pistons contact back of brake pad). Apply adhesive film to the backplate of the piston-side brake lining. 5. IMPORTANT: Be absolutely certain to not allow paste between friction surfaces of the pad and disc! 3. Brake Bedding Process: a) Before trip, the mileage incurred must be clarified with the customer (approx. 30 miles). b) Select a suitable route so speeds of approximately 65 MPH can be achieved. c) Brake the vehicle 15 times with a brake pressure of approx. 30 bar (have the passenger read it out using XENTRY) from 62 MPH to 30 MPH (no emergency stops and no braking in the ESP control range). Maintain a cooling distance of approx. 1 mile between brake applications. d) Finally drive approx. 3 miles to allow the system to cool. e) Reassess noise.
OTA - 20250100102025-01-14. Over-the-air update. ELECTRICAL SYSTEM. Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain MY21-25 C-Class, CLA, EQB, AMG GT, EQE, EQS, G-CLASS, GLB, GLC, GLE, GLS, S-CLASS, AMG SL (206, 118, 243, 290, 192, 294, 295, 296, 297, 465, 247, 254, 167, 223, and 232 platform) vehicles, the MBUX multimedia system does not correspond with the latest series production configuration. The MBUX multimedia system control unit will receive an OTA software update. MBUSA will conduct an OTA service campaign. Remote software updates are automatically downloaded and installed in the customer’s vehicle free of charge and do not require a dealer visit. No customer letter will be mailed for this OTA software update.
LI46.80-P-0780432025-01-10. Service bulletin. ELECTRICAL SYSTEM. Complaint Message in the instrument cluster regarding rear axle steering • In the short test, the fault > Actuator blocked < appears Cause Vehicle may detect high adjustment force in the rear axle steering. Remedy NOTE: If hardware and software numbers do not match exactly what is listed below, please follow DTC guided tests. Old Hardware: A 290 460 3300 / 3400 > SW A 290 902 7400 Caution! This hardware cannot be flashed with the new software version. Only the current hardware with the corresponding previous software release can be flashed. Current Hardware: A 290 460 3900 / 4000 >> SW A 290 902 5101 This hardware can be flashed with A 290 902 1005. Flash control unit N68/3 and N68/4 with current software release A 290 902 1005 using XD.
LI09.41-P-0787352024-12-23. Service bulletin. ENGINE. Complaint Check engine light illuminated Fault code present in MRG3 control unit P22C900 - The valve of the exhaust gas turbocharger is jammed closed. Cause Check valve in charge air pipe jammed closed. Remedy Replaced charge air line with check valve.
LI03.20-P-0787152024-12-23. Service bulletin. ENGINE. Complaint Low engine oil level warning. Engine oil leak under vehicle. Cause Rear crankshaft radial seal rolled during installation Remedy -Check for external oil leak with visual inspection. -Remove inspection cover on left side of transmission and check for oil in bell housing. -If oil is found in bell housing, remove transmission and determine location of leak. Replace rear crankshaft sealing ring if found damaged or leaking. -If ISA is found to be contaminated with engine oil, replace the integrated starter/alternator.
20240900072024-12-06. Service bulletin. ENGINE; ELECTRICAL SYSTEM. Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain MY 2020-2023 CLS (257 platform), E-Class (213 and 238 platform), GLE (167 platform), and AMG GT 4-Door (290 platform) vehicles, the engine control unit software does not correspond to current production specifications. As a consequence, the functionality of the post-catalyst oxygen sensor may be impaired due to increased thermal loading . MBUSA will conduct a service campaign. An authorized Mercedes-Benz dealer will update the engine control unit software.
OTA - 24P54978132024-12-03. Over-the-air update. ELECTRICAL SYSTEM. Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain MY21-25 C-Class, CLA, EQB, EQE, EQS, G-Class, GLA, GLB, GLC, GLE, GLS, GT, S-Class, and SL (206, 118, 243, 294, 296, 465, 247, 254, 167, 192, 223, and 232 platform) vehicles, the MBUX multimedia system does not correspond with the latest series production configuration. The MBUX multimedia system control unit will receive an OTA software update. MBUSA will conduct an OTA service campaign. Remote software updates are automatically downloaded and installed in the customer’s vehicle free of charge and do not require a dealer visit. No customer letter will be mailed for this OTA software update.
LI27.19-P-0725882024-11-27. Service bulletin. POWER TRAIN. Complaint Transmission control unit Y3/8n4 (fully integrated transmission control unit (VGS)) not listed in quick test and/or no communication possible with VGS. Cause Transmission control unit Y3/8n4 Remedy It is important that LI54.15-P-057373 is processed before replacing any component parts (transmission 722.9). After processing and complying with the above documents, perform a reset on the transmission control unit Y3/8n4 (VGS) (ignition reset), check that the transmission connector is seated correctly and inspect the PINs for concerns. If communication with the VGS cannot be established afterwards, the component part 'electrohydraulic controller unit (EHS)' must be replaced, as it is not possible to transfer the valve characteristics under the above-mentioned conditions. Installation of a VGS repair kit is not permitted in this case.
LI82.85-P-0784732024-11-23. Service bulletin. ELECTRICAL SYSTEM. Complaint After a control unit replacement of "N112/9 - control unit for telematics services (HERMES)" or the "N112/2 - control unit for telematics services (RAMSES)", the Digital Extras (previously Mercedes me) cannot be activated. The DTC B15CE00 is active or active+saved. In vehicles with "N112/9 - control unit for telematics services (HERMES)": • The message "SOS - service not activated" permanently lights up in the instrument cluster AND the actual value "Error when replacing certificate (CEP.36)" is displayed in the actual values for the activation status under "Registration status" (see picture 1). • In the control unit log of the "N112/9 - control unit for telematics services (HERMES)", the registration error "CEP Invalid VIN/UniqueID combination" is displayed. In vehicles with "N112/2 - control unit for telematics services (RAMSES)": • The actual value "Error when replacing certificate (CEP.36)" is displayed in the actual values for the activation status under "Registration status" (see picture 1). • In the control unit log of the "N112/2 - control unit for telematics services (RAMSES)", the registration error "CEP_ VIN_UNIQUEID_INVALID" is displayed. The emergency call is not impaired. Cause In the event of a control unit replacement, sporadic problems in the back end could result in data from the new control unit not being updated in the back end system. Remedy Please create a TIPS case. In some cases, the problem rectifies itself on its own after a little while.
LI20.40-P-0785932024-11-22. Service bulletin. ENGINE. Complaint Engine cooling fan running for an extended time after switching off vehicle. Cause Optimized thermal management in latest PTCU software. Remedy This is a normal function in the latest PTCU software. Engine fan will operate for up to 20 minutes after ignition is switched off. Note: Repair work should only be performed if a clear malfunction is identified
LI54.10-P-0786052024-11-19. Service bulletin. ELECTRICAL SYSTEM. Complaint The 12V battery (A0009824113) cannot be mounted with the holder (A2175453100) provided. Cause Incorrect documentation in replacement parts system. Holder is only intended for model series 217. Remedy Mount new 12V battery on old holder (see attachment).
LI82.10-P-0780692024-11-13. Service bulletin. EXTERIOR LIGHTING; VISIBILITY/WIPER. Complaint Rear lamps fogged up/not leaktight. Cause Fogging of the rear lamps is a natural phenomenon, which can occur under certain climatic conditions. This does not lead to any technical impairment of the rear lamps. Remedy Rear lamp: Remedy 1: Clearing fogged/condensed rear lamps: 1. Drive the vehicle into the workshop (temperature higher than +18 °C/+64.4 °F) Note: Do not wash the vehicle or subject it to high-pressure cleaning before the defogging test. 2. Switch off the engine and connect battery support via a charger. 3. Open the trunk. 4. Switch on the exterior lighting. 5. Leave the vehicle in this state for 60 minutes. 6. Check for formation of condensation -> a significant reduction in the formation of condensation must be clearly recognizable (defogging progress). Note: -If no reduction in the degree of fogging is visible, the rear lamp is defective and must be replaced. -It is not physically possible to defog the headlamps completely – some residual fogging may remain. Fogging does not impair the functionality or the service life of the rear lamps. -Simultaneous fogging of multiple component parts indicates extreme climatic conditions and also does not impair the functionality or the service life of the rear lamps. Remedy 2: You can recognize a defective rear lamp as follows: 1. Check the rear lamps to ensure that no external damage is present, and that the differential aeration cells and the diaphragm are present and correctly seated. -> If there are signs of external damage on the rear lamp, the component parts must be replaced as per WIS instructions. 2. Check the electrical connectors of the plugs and pins. -> If moisture/corrosion/etc. is present, the component part must be replaced as per WIS instructions. 3. Check for leak tightness -> Close all openings with Terostat IX or similar and establish and stabilize via an overpressure (40–50 mbar) via the plug. -> In the event of a sudden pressure drop, the component part must be replaced as per WIS instructions. Note: External damage to the rear lamps does not constitute a warranty or goodwill case.
LI27.10-P-0758692024-11-12. Service bulletin. POWER TRAIN. Complaint Only vehicles with a variable transfer case are affected. Can be identified through control unit N45 or N15/7 in the quick test When accelerating with light load, vibrations or jolting sensation may come from the drivetrain Cause Modified oil quality of the transfer case over time Remedy Check initial quick test for faults in the following control units N45 - All-wheel drive (ARS) N127 - 'Drivetrain' (PTCU) control unit Y3/8 - Transmission control for 9-gear transmission (VGS) N3/10 - Engine electronics for combustion engine If faults are present, process them as per the guided test in Xentry If no faults are present: Check the oil level of the transmission If the oil level is correct: Unplug the connector for the transfer cases control unit Reassess the vehicle on a subsequent test drive If the complaint no longer occurs: Perform an oil change of the transfer case according to WIS specifications After please complete all transfer case Tech-in processes located under VG control unit Adaptations tab - Resetting the oil service data - Calibration of N15/7 Perform road test of vehicle to bring transmission to operating temperature ( >60C ) Operate vehicle in full circle with steering at full lock - 5x to the left - 5x to the right Reassess the vehicle following the oil change and teach in If the problem continues to occur with the plug removed or after the oil change has been carried out: Create a TIPS case with the following data Initial quick test with fault freeze frame data EEPROM data from Y3/8 Transmission control unit EEPROM data from N45 All-wheel drive Injector performance data
LI77.25-P-0737492024-11-12. Service bulletin. STRUCTURE:BODY; ELECTRICAL SYSTEM. Complaint Rear spoiler sporadically remains in opened position or does not extend and a fault message appears in the instrument cluster. The rear spoiler can then no longer be retracted manually using the button. The function of the rear spoiler is re-established after an ignition reset and the fault message is no longer present in the instrument cluster. Cause Possible causes: • Coding of the AMG DRIVE UNIT for recognition of Hall sensor when retracting rear spoiler. • Hardware tolerances / hardware wear Remedy If new software for the AMG DRIVE UNIT is available, carry out the software update. If the vehicle already has the most current version of the AMG DRIVE UNIT software installed, conduct SCN coding of the AMG DRIVE UNIT. Software remedy: Up to YoM 19/2 -> AMG Drive Unit N145/1 Software A001 902 6208 As of YoM 20/1 up to YoM 20/2 -> AMG Drive Unit N145/1 Software A001 902 6108 As of YoM 21/1 -> AMG Drive Unit N145/1 Software A001 902 6008 Then check the currently learned actual values under the path "DRVU -> Actual values -> Rear wing sensor system": Are the actual values all in the specified range (green): --> Subject the vehicle to a final inspection/test drive and, if the findings report is OK, hand it over to the customer. If the actual values are outside of the specified range (red) or final inspection is not OK: --> Initialize the rear spoiler (if necessary up to 5x) until all values are in the target range (green). If subsequently OK: -> Subject the vehicle to a final inspection/test drive and, if the findings report is OK, hand it over to the customer. If still not OK: -> Check screw connection of rear spoiler adjuster (see attachment 1) for tight seating. If screws loose: -> Bond loose screw (see following steps and attachment 3 to 5). 1. Unscrew screw with Torx TX25 screwdriver from the housing guide. 2. Dip screw in Loctite 603 (at least 3 threads) 3. Screw the screw back into the housing guide with 2 Nm torque. (IMPORTANT: Loctite 603 finger-tight after 8 minutes and cured after 24 hours) 4. Initialize rear spoiler after the curing time. 5. Subject the vehicle to a final inspection/test drive and, if the findings report is OK, hand it over to the customer. If screws tight: -> Create a TIPS case with the following information: 1. When exactly does the fault message appear (at which speed, when accelerating or braking, automatic mode, etc.)? 2. Is the problem sporadic or continuous? 3. Does the fault message disappear following an ignition reset/BUS idle and is the function of the rear spoiler then (momentarily) restored? 4. Is the fault reproducible and if so, how? Attach the following files: 1. Quick test 2. Control unit log for AMG DRIVE UNIT + rear wing (DRVU + HFL) 3. IC event memory 4. Currently learned actual values prior to initialization 5. Currently learned actual values following initialization 6. Power consumption of rear spoiler (XENTRY: Configuration -> Coding -> Coding of power parameter) 7. Photo of the label on the rear spoiler drive (IMPORTANT: Production/manufacturing date of the rear spoiler must be easily readable, for an example see attachment 2)
LI27.60-P-0777042024-10-26. Service bulletin. POWER TRAIN. Complaint DSI selection lever module cannot be switched to park position "P" - malfunction of "P" button. Vehicle will shift into park automatically at ignition off or with opening the driver door. Cause Possible causes: 1. Contamination/ingress of dust 2. Short circuit due to ingress of water Note: This repair may not be covered by warranty due to outside influence. Remedy Clean printed circuit board under plastic housing and button "P": 1. Remove DSI (AR27.60-P-0901FRX) 2. Remove housing of DSI (see picture 1) 3. Remove cover around "P" button above printed circuit board (see picture 2) 4. Check printed circuit board: Liquid residues and/or contamination (cf. picture 3) 5. Check "P" button: Water residues and/or contamination (cf. picture 4) 6. Carefully clean the affected areas. We recommend an electrical contact cleaner such as BW-100 or CRC QD Electronic Cleaner as example. 7. Assemble and check for proper function
LI82.35-P-0784672024-10-25. Service bulletin. VISIBILITY/WIPER; STRUCTURE:BODY. Complaint Washer fluid system leaks Cause Various possible causes: 1. Washer fluid reservoir itself. 2. Seal on washer fluid pump/washer fluid reservoir. 3. Washer fluid pump. 3.1. Distributor housing leaks. 3.2. Pump fitting leaks. 3.3. Washer fluid hose cannot be snapped into place on pump fitting. 3.4. Washer fluid hose will not stay on pump fitting, although connector OK. 4. Washer fluid line. 4.1 Connector will not stay on pump fitting because it is broken. 4.2 Sealing ring in connector missing. 4.3 Sealing ring in connector fitted, but deformed and therefore leaks. 4.4 Damage to washer line by animal. 5. Seal on heating washer fluid reservoir/washer fluid reservoir. Remedy Replace defective component parts only. Do not replace any adjacent component parts that are intact. Note: Repair kits for washer line hoses do exist to allow patches for line damage.
LI54.71-P-0784982024-10-22. Service bulletin. ELECTRICAL SYSTEM; WHEELS. Complaint "Active Emergency Stop Assist Currently Unavailable" and "Active Steering Assist Inoperative" instrument cluster messages along with Tire Pressure Light on in Instrument Cluster. Cause Both systems are temporarily unavailable due to low tire pressures. An active tire pressure monitor light may result in some assistance features being temporarily unavailable until tire pressures are corrected. Remedy Check/adjust tire pressures and reset monitoring through the instrument cluster.
NCU - 20220700042024-10-21. Service campaign. FUEL/PROPULSION SYSTEM. Mercedes-Benz AG ("MBAG"), the manufacturer of Mercedes-Benz vehicles, has determined that on certain Model Year (“MY”) 2018 - 2024 E-Class, S-Class & AMG GT (213, 217, 222, 223 and 290 platforms) vehicles, the low pressure fuel line does not meet current production specifications. Therefore, it is possible that accelerated aging in the area of connection could occur, resulting in a leak. A risk of fire can be ruled out. MBUSA will conduct an Emission Service Campaign. An authorized Mercedes-Benz dealer will replace the braided hose of low-pressure fuel line and install a heat shield over the new braided hose.
LI15.40-P-0779472024-10-18. Service bulletin. ELECTRICAL SYSTEM; ENGINE. Complaint Combustion engine could no longer be started, only electric driving possible. Cause High-voltage belt-driven starter-alternator faulty. Remedy Requirement: Prior to the implementation of the test work, it must be ensured that the person carrying out this work has successfully completed the required HV qualification to work on HV system.
LI82.85-P-0784732024-10-09. Service bulletin. ELECTRICAL SYSTEM. Complaint After a control unit replacement of "N112/9 - control unit for telematics services (HERMES)" or the "N112/2 - control unit for telematics services (RAMSES)", the Digital Extras (previously Mercedes me) cannot be activated. The DTC B15CE00 is active or active+saved. In vehicles with "N112/9 - control unit for telematics services (HERMES)": • The message "SOS - service not activated" permanently lights up in the instrument cluster AND the actual value "Error when replacing certificate (CEP.36)" is displayed in the actual values for the activation status under "Registration status" (see picture 1). • In the control unit log of the "N112/9 - control unit for telematics services (HERMES)", the registration error "CEP Invalid VIN/UniqueID combination" is displayed. In vehicles with "N112/2 - control unit for telematics services (RAMSES)": • The actual value "Error when replacing certificate (CEP.36)" is displayed in the actual values for the activation status under "Registration status" (see picture 1). • In the control unit log of the "N112/2 - control unit for telematics services (RAMSES)", the registration error "CEP_ VIN_UNIQUEID_INVALID" is displayed. The emergency call is not impaired. Cause In the event of a control unit replacement, sporadic problems in the back end could result in data from the new control unit not being updated in the back end system. Remedy Please create a TIPS case. In some cases, the problem rectifies itself on its own after a little while.
LI82.70-P-0774332024-09-28. Service bulletin. ELECTRICAL SYSTEM. Complaint During a phone call, the called party has difficulty understanding/cannot understand the driver, or interference/background noises are audible to the called party during a call. It becomes increasingly difficult to understand as the speed rises. Cause A. Seating of the microphones in the headliner. Side edges are covered by the textile cover (see picture "1") B. Assembly of microphones (B25/20 or B25/21) in the headliner. C. Dirt inside the microphone housing Remedy 1. Press finger on rear of microphone (on adhesive tape) 2. Remove microphone cap from the front 3. Eliminate protruding material residues of the microphone cutout at the headliner, e.g. with a soldering iron. The microphone must be seated in the headliner as shown in picture "2". 4. Push microphone from behind until it is firmly pressed into the headliner 5. Maintain pressure and press/clip cap into microphone from the front. Note: The cover cap must be clearly heard and felt to engage. 6. This procedure must be carried out on both microphones (B25/20 and B25/21) Note: • It is recommended to replace the cover caps. • The non-woven cloth in the cover cap protects the microphone from soiling and must not be removed. NOTE: The information contained in this document is intended for use by trained, professional technicians with the knowledge to properly and safely perform diagnosis and repairs on Mercedes-Benz vehicles, using Mercedes-Benz approved tools and equipment. It informs service technicians about conditions that could occur in certain vehicles and provides information that could assist in proper vehicle diagnosis, service, or repair. It does not indicate that a defect is present in any vehicle referenced in this document nor does it imply warranty coverage. DO NOT assume that a symptom or condition, or a described cause of a symptom or condition, affects any particular vehicle or groups of vehicles, or that a described repair applies to any particular vehicle or groups of vehicles. There can be multiple causes resulting in the same or similar symptoms or conditions described in this document, and trained professional service technicians must use their diagnostic skills to make evaluations on a case-by-case basis. The information contained in this document does not guarantee warranty coverage nor does it extend the vehicle’s warranty in any way.

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.