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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Only bulletins with component: Transmission and driveline are shown. Show all
| LI27.00-P-073124 | 2026-10-06. Service bulletin. POWER TRAIN. 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. |
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| LI27.10-P-075869 | 2026-10-05. Service bulletin. POWER TRAIN. Complaint Only vehicles with a variable transfer case are affected. This 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. It may be mistaken for a harsh shift. Cause Modified oil quality of the transfer case over time Remedy 1. Check initial quick test for faults in the following control units. N45 or N15/7 ‑ 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: 2. Check the transmission oil level If the oil level is correct: 3. Unplug the connector for the transfer cases control unit and reassess the vehicle on a subsequent test drive If the complaint no longer occurs with the control unit disconnected: 4. Perform an oil change of the transfer case according to WIS specifications ‑ Collect an oil sample of the original fluid 5. Complete all transfer case Tech‑in processes located under VG Control Unit > Adaptations ‑ Resetting the oil service data ‑ Calibration of N15/7 5. Perform road test of vehicle to bring transmission to operating temperature (>60C ) 6. Operate vehicle in full circle with steering at full lock ‑ 5x to the left ‑ 5x to the right Return the vehicle to the client and request they drive the vehicle for at least 200 miles and return if the concern is not resolved. The extended drive will ensure the clutches are properly conditioned with the new oil and should resolve the concern. If this LI has already been applied to the vehicle, please submit a TIPS case to the Powertrain inbox with the following information: ‑ Initial quick test with fault freeze frame data ‑ Initial transmission EEPROM data ‑ VGS and Transfer Case Control Unit Log (N45 or N15/7) ‑ Special Acquisition Data .txt file (Transfer Case Control Unit > Special Procedures > Procedures for support queries to market support > Special Data Acquisition) ‑ Photo of the original oil condition ‑ What color was the fluid drained from the transfer case before the oil change? ‑ Was an oil sample collected, and can you provide a photo of the original fluid? ‑ What color and part number fluid was used during the oil change? ‑ How far was the vehicle driven after? |
| LI27.00-P-073124 | 2026-09-30. Service bulletin. POWER TRAIN. 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 ‑ AMG sports models (AMG 43 and AMG 53 with converter) NAG3 ‑ AMG 63 NAG3 ‑ Hybrid NAG3 Facelift (automatic transmission 725.1) NAG3 facelift (725.1) with engine 139/177 (AMG 43/63) 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: Perform quick test ·Access the transmission control unit via XENTRY Diagnosis ·Select "A customer complaint has been received" and carry out all subsequent operation steps (IPR diagnosis path). ·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. |
| LI27.00-P-075630 | 2026-08-10. Service bulletin. POWER TRAIN. Complaint This document is intended as a pre-case diagnostic reference for transmission related concerns. It will also ensure that if a case is necessary, all supporting documentation is available. This should not be used on its own as justification for creating a TIPS case. Cause The root cause will vary depending on the complaint. The goal of this document is to provide diagnostic checks and procedures that may help resolve customer complaints without opening a TIPS case. Remedy Before opening a transmission-related TIPS case, the following steps must be performed to ensure all relevant data has been collected and possible remedies (when applicable) have been performed. Please Note: At minimum, the documents below must be collected before proceeding to ensure the data in its original state when the vehicle arrived is captured. - Initial Quick Test w/ Freeze frame data - VGS Control Unit Log - Initial EEPROM data (.txt format) - IPR Result (if applicable. See LI27.00-P-073124 - Transmission diagnosis using the Intelligent Predictive Repair (IPR) tool) - Transmission Heath Page If the vehicle has previously been repaired for the same concern, note the date, mileage, and TIPS case or RO number, along with a brief description of the prior work performed. IPR Guidance: The IPR recommended repair should be completed prior to following any steps in this LI and prior to case creation. IPR repairs do not require additional warranty approvals or a TIPS case to validate/confirm the results. To ensure efficient case handling, please avoid opening TIPS cases for this reason. For further information regarding IPR please see the following documents: LI27.00-P-073124 - Transmission diagnosis using the Intelligent Predictive Repair (IPR) tool Oil Pan Condition Evaluation: In some situations, IPR will advise checking the oil pan condition and determining a repair based on the evaluation. Example photos in Xentry can be found in two ways: • Use the blue hyperlink in the IPR result, and it will take you to the Condition check of transmission oil • Navigate to Xentry Bluebook > Help for control unit > Condition check of transmission oil If a different repair that what is recommended by IPR is performed, attaching photo documentation of the complaint vehicle oil pan and the IPR example to the claim is required. Reproducing the Concern: Proper evaluation of transmission concerns generally requires the condition to be reproducible. It is recommended to compare the vehicle to a similar model, if available, to help determine whether the shift behavior is characteristic of the drivetrain or uncharacteristic for the vehicle. If the concern cannot be duplicated: • A test drive with the customer may assist in understanding and reproducing the complaint. • The vehicle shift quality should be compared to a known-good vehicle with identical drivetrain and model year. • Check Shift Quality History (VGS Control Unit > Adaptations > Shift Quality History) Shift Quality History will show the last 5 noticeable harsh shifts and some of the parameters in which it occurred. You can use this to attempt recreation of the operating conditions and increase likelihood of reproducing the complaint. Complaint A: Shift Quality Note: Certain AMG variants may exhibit more firm and noticeable shift behavior as a normal characteristic. Refer to LI27.60‑P‑075147 for additional information. 1. Perform Valve flushing procedure 2. Perform 5 Torque Converter adaptions in a row - Allow the vehicle to warm up naturally, DO NOT power brake as it will increase the temperature in the torque converter. - After the 5th adaptation, collect a screen shot showing all 5 on one page 3. Perform a standstill adaption - collect a screen shot Recheck vehicle operation. If the concern has not improved, driving adaptations should be performed to target specific gear shifts. |
| LI27.00-P-080840 | 2026-08-05. Service bulletin. POWER TRAIN; UNKNOWN OR OTHER. Complaint Mercedes-Benz USA is currently experiencing limited availability of transmission fluid specification ATF 236.17 due to a global supply constraint. 236.17 ATF 1L and 5L (PNs: A002989060312 and A002989060313) bottles are out of stock or in limited supply at Zep. This LI has been created with the following intention: - Provide dealers with additional workshop-focused guidance regarding the current ATF 236.17 supply constraint and the planned introduction of ATF 236.18. - Supplement existing communications and address common workshop questions related to maintenance, repairs, and fluid applicability. - Provide technical clarification and practical workshop guidance during the temporary supply constraint period. Dealers should continue to reference the latest News Channel Updates (NCUs) for the most current information regarding availability, ordering processes, supply status, and other related updates. Cause Damage to the Shell production facility has resulted in 236.17 oil supply being reduced to 50% of normal output until the end of 2026. Remedy Please first check Latest NCU updates for latest detailed information. Please continue placing orders through Paragon as normal. Supply is expected to remain reduced and allocation measures are currently in place. We ask for your patience through this restricted supply period. Most orders will be filled in the order in which they were received, as supply is replenished. Those dealers with zero inventory, and pending orders, will receive priority. We expect supply to be stabilized in September 2026. Approved Fluids: Only use transmission fluid from the approved list found on the Mercedes-Benz Operating Fluids website. Non-approved fluid will result in mechanical damage to the transmission and must be avoided. https://operatingfluids.mercedes-benz.com/sheet/236.17 Approved fluids can be claimed as follows if there is no Mercedes-Benz part number: Part # ATFSUB1L - TRANSMISSION FLUID 1 LITER ATFSUB5L - TRANSMISSION FLUID 5 LITER Dealerships with Zero Inventory AND Grounded Vehicles: If a vehicle is currently grounded for repair at your dealer due to no 236.17 inventory, we may be able to expedite your order. Please open a StarSupport ticket including the following information: (Parts Related Inquiry>National Accounts>Zep) • LI document number • Short explanation of repair needed for grounded vehicle • Current days down of RO Maintenance and Service Interval Guidance Published maintenance intervals remain unchanged. Vehicles should continue to be maintained in accordance with the applicable maintenance schedule. This LI does not revise or extend any published maintenance interval requirements. If all required parts and materials are not available prior to scheduling or beginning a transmission service, dealers should consider postponing routine preventative transmission maintenance until the necessary parts become available. For vehicles that have not yet reached the applicable maintenance interval and do not exhibit transmission-related concerns, there is no need to recommend preventative transmission services prior to the scheduled maintenance interval. When evaluating whether routine transmission maintenance can be deferred until parts become available, dealers should consider: • Overall vehicle condition • Vehicle usage and operating conditions • Presence of transmission-related symptoms or customer complaints • Customer expectations and vehicle operating requirements • Availability of required parts and materials Introduction of New Fluid Specification 236.18 Mercedes-Benz is currently preparing the introduction of ATF 236.18 as an additional approved transmission fluid solution for applicable NAG3 transmissions. At the time of publication of this LI, ATF 236.18 is not yet available for dealer ordering or workshop use in the U.S. market. See attachment for further details. |
| LI35.30-P-058566 | 2026-07-14. Service bulletin. POWER TRAIN. 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). |
| PSL-NCU Return Parts 5/22 | 2026-06-01. Other. POWER TRAIN; STRUCTURE:BODY. 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, June 11, 2026. After June 11th, 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. |
| PSL-NCU Return Parts 5/15 | 2026-05-18. Other. SUSPENSION; POWER TRAIN. 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, June 4, 2026. After June 4th, 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. |
| LI27.60-P-080449 | 2026-04-14. Service bulletin. POWER TRAIN. Complaint Harsh upshifts, downshifts, or jolting in lower gears when accelerating. Cause Incorrectly installed (rotated) rotational speed sensors on the EHS (VGS Control Unit) can cause abnormalities in signals. As a result, poor adaptation values are stored and harsh gearshifts are felt. This only affects vehicles with VGS control units produced between days 182-296 of 2025 (July 4, 2025-October 23, 2025). Remedy 1. Collect initial transmission EEPROM file 2. Check EEPROM .txt file for VGS control unit serial number and production date (attachment figure 1) - If the valve body is already removed, you can inspect the control unit for its stamped serial number (attachment figure 2) If the production date is or is within 25182-25296 (07/4/25-10/23/25): The complete valve body will require replacement. 1. Remove transmission oil pan & inspect fluid/pan/filter condition - compare findings to extended fluid condition examples provided in Xentry blue book under general information for VGS 2. Replace complete EHS valve body, fill to near max fluid level, & complete initial start-up - Ensure all oil guide pipes are installed in the new valve body to prevent a new concern after replacement. (See photos in WIS instructions) - Verify the new valve body production date is outside of day 182-296 of 2025 (attachment figure 2) If the production date is outside of this range: This LI is not applicable. 1. Perform IPR and follow recommended instruction |
| NCU - 2025120009 | 2026-03-14. Service campaign. ELECTRICAL SYSTEM; POWER TRAIN. Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain subject vehicles, the drivetrain control unit does not meet current production specifications. The system may experience an excessively high quiescent current draw on the vehicle, which could lead to an increased discharge of the 12V battery. MBUSA will conduct a service campaign. An authorized Mercedes-Benz dealer will update the drivetrain control unit software. |
| LI27.19-P-080219 | 2026-02-17. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN. Complaint Check engine light on with the following fault is current in the VGS Control Unit: P084300 Oil pressure sensor 'A' has a short circuit to positive stored in VGS control unit. Cause Electrical failure of oil pressure sensor integrated into VGS Control Unit Remedy Intelligent Predictive Repair (IPR) recognizes this fault pattern and will provide the necessary repair suggestion. 1. Perform IPR and follow the recommended procedures 2. Replace complete EHS valve body, fill to near max fluid level, & complete initial start-up - Ensure all oil guide pipes are installed in the new valve body to prevent a new concern after replacement. |
| LI27.10-P-075869 | 2026-02-04. Service bulletin. POWER TRAIN. Complaint Only vehicles with a variable transfer case are affected. This 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. It may be mistaken for a harsh shift. Cause Modified oil quality of the transfer case over time Remedy 1. Check initial quick test for faults in the following control units. N45 or N15/7 - 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: 2. Check the transmission oil level If the oil level is correct: 3. Unplug the connector for the transfer cases control unit and reassess the vehicle on a subsequent test drive If the complaint no longer occurs with the control unit disconnected: 4. Perform an oil change of the transfer case according to WIS specifications - Collect an oil sample of the original fluid 5. Complete all transfer case Tech-in processes located under VG Control Unit > Adaptations - Resetting the oil service data - Calibration of N15/7 5. Perform road test of vehicle to bring transmission to operating temperature ( >60C ) 6. Operate vehicle in full circle with steering at full lock - 5x to the left - 5x to the right Return the vehicle to the client and request they drive the vehicle for at least 200 miles and return if the concern is not resolved. The extended drive will ensure the clutches are properly conditioned with the new oil and should resolve the concern. If the concern continues to occur with the control unit disconnected or after the above steps have been performed, please submit a TIPS case to the Powertrain inbox with the following information: - Initial quick test with fault freeze frame data - Initial transmission EEPROM data - VGS and Transfer Case Control Unit Log (N45 or N15/7) - Photo of the original oil condition - What color was the fluid drained from the transfer case before the oil change? - Was an oil sample collected, and can you provide a photo of the original fluid? - What color and part number fluid was used during the oil change? - How far was the vehicle driven after? |
| LI27.35-P-080160 | 2025-12-24. Service bulletin. POWER TRAIN. Complaint (Original LI document #: LI27.35-P-079039) Clicking noises from the electro-hydraulic control unit (EHS) when the vehicle is stationary and ECO Start/Stop is active (combustion engine is off). The noise is more noticeable outside the vehicle and in acoustically shielded areas such as closed rooms or garages. Cause The noise in the valve body (EHS) is caused by superimposed pressure peaks acting on the valves. This phenomenon occurs only after a certain running-in period due to the influence of micro-contamination in the valve bores. Remedy A hardware modification of the electro-hydraulic control unit (EHS) is currently being implemented (no change to the part number). This will be incorporated into series production and as a spare part starting from 12/2025. This is only a comfort-related complaint and has no impact on the functionality or service life of the transmission. For sensitive customers, the following measures can be performed: 1. Replace the electro-hydraulic control unit (EHS), the oil pan, and the transmission fluid. - Ensure all oil guide pipes are installed in the new valve body to prevent a new concern after replacement. (See attached location guide) |
| LI27.35-P-079971 | 2025-11-11. Service bulletin. POWER TRAIN. Complaint Possible complaints about shift quality, issues with learning the park lock, and slipping/rinse entries in the EEPROM or Transmission Health system following the replacement of the below components: - The electrohydraulic control unit (EHS valve body) in transmission 725.0/725.1 - The repair kit for the control unit (VGS) in transmission 725.0 Cause Missing, incorrectly installed, or damaged guide tubes on the EHS valve body. Remedy Check for the correct installation of the guide tubes (refer to attachments under “Cause”), correct installation if necessary. Parts Catalog References: NAG3M 725.1 AND NAG3C 725.0 (AMG only): Part numbers 100, 120, 150, 160 NAG3C 725.0 (Non AMG): Part numbers 280, 290, 330, 340 NOTE: If any of these guide tubes are not installed and the vehicle is driven, it will create several rinse and slipping events in the EEPROM data. These values caused by incorrect installation need to be erased to prevent future misdiagnosis. Submit a TIPS case to the Powertrain inbox with the following to receive the necessary reset password: - Initial Quick Test w/ Freeze frame data - VGS Control Unit Log - IPR Result - Initial EEPROM data (before repairs) - Latest EEPROM data - Photo of oil level ultrasonic measurement next to XENTRY specifications Please provide detail regarding the reasoning for the initial replacement in your workshop findings and measures performed. (This topic was covered in the July 2022 and July 2024 Passenger Car Tech Topics) |
| LI27.10-P-075869 | 2025-11-06. Service bulletin. POWER TRAIN. Complaint Only vehicles with a variable transfer case are affected. This 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. It may be mistaken for a harsh shift. Cause Modified oil quality of the transfer case over time Remedy 1. Check initial quick test for faults in the following control units. N45 or N15/7 - 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: 2. Check the transmission oil level If the oil level is correct: 3. Unplug the connector for the transfer cases control unit and reassess the vehicle on a subsequent test drive If the complaint no longer occurs with the control unit disconnected: 4. Perform an oil change of the transfer case according to WIS specifications - Collect an oil sample of the original fluid 5. Complete all transfer case Tech-in processes located under VG Control Unit > Adaptations - Resetting the oil service data - Calibration of N15/7 5. Perform road test of vehicle to bring transmission to operating temperature ( >60C ) 6. Operate vehicle in full circle with steering at full lock - 5x to the left - 5x to the right 7. Perform an extended 200mi road test to ensure the clutches are properly conditioned with the new oil. 8. Reassess the concern and release the vehicle if no longer present. If the concern continues to occur with the control unit disconnected or after the above steps have been performed, please submit a TIPS case to the Powertrain inbox with the following information: - Initial quick test with fault freeze frame data - Initial transmission EEPROM data - VGS and Transfer Case Control Unit Log (N45 or N15/7) - Photo of the original oil condition - What color was the fluid drained from the transfer case before the oil change? - Was an oil sample collected, and can you provide a photo of the original fluid? - What color and part number fluid was used during the oil change? - How far was the vehicle driven after? |
| LI35.31-P-079847 | 2025-10-07. Service bulletin. POWER TRAIN. Complaint Complaints of oil leaking from rear differential oil pan area. Cause In the groove where the pan seal is placed, there may be imperfections (porosity) in the casting causing fluid to leak past the seal. The supplier states this only affects rear differentials with 2023 production date. The production date can be found stamped on the housing cover (see attachment). Remedy 1. Follow the attached instructions to inspect the rear differential cover for porosity. 2. Repair the vehicle with the applicable repair kit for the chassis. - The new oil pans that come with the repair kit should be produced in 2024 and not have this issue. *When submitting the claim, please reference this LI document and if porosity was found.* |
| LI27.19-P-072588 | 2025-09-18. 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 For vehicles with 722.9 transmission: Ensure LI54.15-P-057373 is performed before replacing any component parts. After processing and complying with the above document(s): 1. Perform an ignition reset on Y3/8n4 (VGS) 2. Inspect transmission connector for loose connections, damaged wiring or pins and any other concerns If communication with the VGS cannot be established, the complete valve body ('electrohydraulic controller unit (EHS)') must be replaced. Installation of a VGS repair kit is not permitted in this case as it is not possible to transfer the necessary valve characteristics without communication with the original control unit. |
| LI33.30-P-056665 | 2025-06-03. Service bulletin. POWER TRAIN. Complaint Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end). The clunk is heard once when changing from forward to reverse (and vice versa). 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 micromovement in the connection 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 and must be tightened to the specified torque. Remedy Coat contact surface of side shaft with wheel bearing with Molykote paint. To do this, proceed as follows: 1. Remove outboard side shafts (extract outer joint gearing from wheel hub) 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") using Molykote and leave to dry for one hour in removed condition 4. Reinstall side shafts |
| LI27.35-P-079039 | 2025-03-27. Service bulletin. POWER TRAIN. Complaint A clicking/ticking/taping noise from underneath the vehicle with engine off during ECO stop event or after parking See video for example Cause Noise originates within the transmission valvebody Remedy Take a video from underneath vehicle recording the noise Pull EEPROM data, Inital Quick Test, and Control Unit Log Please open a TIPs case providing all data to assess next steps. |
| LI27.19-P-072588 | 2024-11-27. 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. |
| LI27.10-P-075869 | 2024-11-12. 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 |
| LI27.60-P-077704 | 2024-10-26. 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 |
| LI27.00-P-075630 | 2024-09-12. Service bulletin. POWER TRAIN. Complaint To insure vehicle down time is kept at a minimum and all required information is available when case is escalated, as well as assist technicians with checks that may help lead in resolving issue without case creation. THIS LI IS NOT TO BE USED AS A REASON FOR CASE CREATION BUT AS A GUIDE IF A CASE IS NEEDED Cause There are, at times, additional steps workshops can do to help diagnose and rectify transmission complaints. Remedy When opening a case for transmissions a EEPROM, Quick Test, and VGS CUL are absolutely necessary Please also check for any relevant LI’s before opening case. Also, recommend having customer fill out Transmission Drivability Diagnostic Worksheet especially if complaint is hard to reproduce or intermittent (Work sheet Location: Xentry Portal >> Local Contents >> Diagnostic Info>> Diagnostic Worksheets ) If a previous repair attempt or visit was made for the same concern please include the date, mileage, and case number if applicable of that repair/visit with a short description of what was done. Follow IPR: ( LI27.00-P-073124 ) All IPR suggestions are covered by warranty and there is no need for cases to confirm IPR. Complete IPR suggestions and close out IPR process. If complaint is not fixed and IPR still suggests the same repair once closed out and run again, then a case may be needed. Transmission Health page is a good indicator of issues within transmission if clutch or brake pack stays NOK after adaptions and unable to be made to a green OK then an internal fault is present. Proceed with replacing affected clutch pack. IF more than 3 are red and NOK replace transmission (include printout with warranty claims) **** FOR 167 chassis with M264 engine B08 may be red and NOK, IGNORE this, B08 is still okay **** Shift complaints: Note: AMG variants are known to have a harsher shift see LI27.60-P-075147 It is always worth comparing to a like vehicle if possible to see if shift is uncharacteristic Perform Valve flushing procedure Perform 5 Torque Converter adaptions in a row (Save the results page) Perform standstill adaptions (Save the results page) Drive adaptions if necessary: Drive C mode keep RPM between 2000-2200rpm and lightly let off pedal to force shift wait 2-3 sec then roll on throttle to rpm back up to 2000-2300 rpm repeat for gears 1-3 *For gears 4-8 allow rpm up to 2700 and let off slightly to force upshift = repeat x 10 *For downshift - highest gear possible 8 or 9 - allow decel with light brake drag (allow at least 5s between downshifts for trans to adapt. Go down to 2nd and repeat x10 *Change to sport mode and repeat process again *Lock car to allow sleep at least 10min and restart and road test for quality. After adaptions a new EEPROM should be recorded and included with the original if opening a case Understand shift complaints need to be reproducible to address. If needed drive with client to reproduce the complaint. If shift complaint is intermittent a CAN trace of the issue occurring will be useful (see attached instructions) Shudder: If there is a shudder monitor torque convertor actual values to see if it occurs during slipping, Additionally can lock up convertor and drive to see if issue is resolved Jolting/Shudder: If the vehicle is AWD: unplug AWD control unit or drive vehicle in dyno mode to see if transfer case is causing the jolt/ harsh shift If located from transfer case check fluid and perform a flush if needed to try to rectify the issue. Vibrations: NVH trace is needed, what level vibration is being experienced and where is it located? Is the Vibration felt in neutral? Dyno mode? Does it change with speed? Etc. Noise complaint: Isolate the noise location using chassis ear. MUST attach a sound recording or video of the noise. Describe when the noise is present: Does it change with gear or speed? Does it occur with vehicle in neutral or in glide mode? Does operating temperature effect noise? Does incline/decline or steering angel effect noise? |
| LI27.19-P-078313 | 2024-08-23. Service bulletin. POWER TRAIN. Complaint Customer states that either the yellow battery indicator lamp is illuminated in the instrument cluster OR a 4MATIC malfunction MIL is present, AND the subject vehicle is affected by the pending recall “Replace Transmission Wiring Harness” (NHTSA ID 24V445). The following DTCs may also be present in the initial quick test: • In N45 - All-wheel drive (AWD): U103E00 – “Communication with the suspension FlexRay has a malfunction” • In N73 - Electronic ignition lock (EZS): U116000 – “A bus keepawake control unit has been detected” Cause Possible water entry into connector X279x1 Remedy Immediately disconnect electrical connector X279x1 and create a TIPS case. Further instructions will be provided in case Please attach the following documents to the TIPS case: • Initial quick test • Instrument Cluster event memory • Detailed photos of both ends of electrical connector X279x1 |
| LI27.00-P-073124 | 2024-07-31. Service bulletin. POWER TRAIN. 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 - AMG sports models (AMG 43 and AMG 53 with converter) ·NAG3 - AMG 63 ·NAG3 - Hybrid |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.