Technical service bulletins are instructions a manufacturer sent its dealers about a known fault. They are not recalls and the work is usually not free, but they are the clearest signal of a problem the manufacturer already knows about.
LI46.00-P-079786
Service Bulletin/Repair Instructions
Complaint Noise from front end thought to be from steering gear. Cause During diagnostics of a front end noise, workshop is under the impression the noise is coming from the steering gear. Remedy If the root cause of the noise cannot be found and is seemingly from the steering rack, perform the below LI's and diagnostics. If they have been performed and the root cause still cannot be determined, a TIPS case must be opened to the Body/Chassis/Entertainment team prior to replacing the steering rack. • LI46.35‑P‑067339 ‑ "Rattling, Humming, Dry Sliding/Gravel Noise When Steering" • LI46.35‑P‑071461 ‑ "Check Tie Rod Outer Joint of Steering Gear" • LI46.10‑P‑077391 ‑ "Knocking Noise In The Area Of The Steering Gear or Steering Column Tube When Braking Or Moving Off; The Steering Wheel Can Also Be Felt To "Crack"" • Remove boot clamps closest to steering gear housing on both left and right (as seen in "Steering Rack Boot Clamp Location"). Pull back boot and inspect for rust, broken end stops, water, or any other anomalies. Keep the boot clamps in case the rack is returned. • If the noise is described as "clacking" or "knocking" when moving the wheel back and forth in quick oscillations and the thrust element in the steering rack has NOT been checked yet, please perform a check and subsequent adjustment, if necessary, as detailed in AR46.20‑P‑0601ME. • Remove sway bar links and see if noise persists. • Perform NVH time‑domain noise diagnosis pointing to the steering rack as the root cause. The TIPS case must contain the following: • Video underneath the vehicle with clearly audible noise while engine is running. • Video inside the vehicle with clearly audible noise while engine is running. • Vehicle checked for history of collisions. • Vehicle history checked for other noise complaints in the area. • List of other checked components (suspension, drive line components, wheel bearings, etc...). • Along with the audible noise, does the feel/noise change through only a certain part of the steering arc sweep? • Provide the thrust element before and after readings.
LI46.35-P-067339
Service Bulletin/Repair Instructions
Complaint During part of the steering movement, it feels heavier or more difficult to steer in the same spot every time. OR Rattling, humming, dry sliding/gravel noise from the electric steering system when steering (see attachment). Complaint does not impact the ability to safely steer or control the vehicle. Cause Ball screw drive (KGT) of electric steering damaged by: 1. External force due to: ‑ Hitting the curb/posts with the front wheels. ‑ Driving over obstacles (e.g. pothole/ threshold/ speed bump/ gully) at an inappropriate speed. 2. Corrosion/ water ingress through a damaged boot (see attachment). ‑ Cracks (1) ‑ High pressure cleaner (2) ‑ Animal bite (3) See various examples listed in the attachments for examples of outside influence. Remedy Remove boot clamps closest to steering gear housing on both left and right (as seen in "Steering Rack Boot Clamp Location"). Pull back boot and inspect for rust, broken end stops, water, or any other anomalies. Replace electric steering. Note: Steering gears replaced due to outside influence or damage must not be claimed under warranty!
LI72.20-P-075746
Service Bulletin/Repair Instructions
Complaint Tailgate opens unintentionally. Cause Accidental or unnoticed activation of the button to open the tailgate on the vehicle key. EXAMPLE: when stored in trouser pocket, handbag etc. Remedy As of the 6th generation, the vehicle key can be recoded so that the tailgate no longer opens as a result of a long press on the button, but by double‑clicking on the button instead. This reduces the likelihood of the button being activated accidentally or unintentionally. The recoding can be carried out as follows: 1. Add SA Code O19 into VeDoc (O for Oscar, not "zero") • an XSS ticket may be necessary to add the SA code 2. Perform SCN coding of EIS N73 control unit 3. Deactivate the vehicle key (a successful deactivation is indicated by the LED lighting up 2x briefly and then 1x for a long period). 4. Place the vehicle key in the storage compartment on the key symbol and turn on the ignition. IMPORTANT: all other vehicle keys must be outside the recognition range of the vehicle when doing this! Perform steps 3 and 4 successively for all vehicle keys. Notes: 6th, 7th and 8th generation keys can be deactivated as follows: Up to modification year 22/1 by double clicking the "Lock button" As of modification year 22/1, by press and holding the “Lock button", then double‑click the “Unlock button" at the same time. On model series 167, the storage compartment with the key symbol is located in the armrest. The SCN coding from the EZS is only transferred correctly to the vehicle key under the following conditions: Only one vehicle key is located in the vehicle, this key has been deactivated and it is positioned on the marking in the storage compartment for the data transfer. The costs for this adaptation are to be borne by the customer. For the newer BR 174, 178, 244, 248, 520, and 540, a software update must be initiated, as there is no way to perform SCN coding.
LI54.71-P-079104
Service Bulletin/Repair Instructions
Complaint Traffic sign symbol for "Traffic Sign Assist" is blinking in instrument cluster without obvious cause usually with one of the following scenarios: • Flashing without a speed limit ("‑ ‑"). • Flashing when current vehicle speed is under speed limit. • Flashing between US speed limit symbol and European speed limit symbol. NOTE: • Verify that the concern falls under one of the attachment videos. If not, then it is outside of the scope of this LI. • This also does not cover "Traffic Sign Inoperative" messages on the instrument cluster. Cause There are two identified reasons for this concern: 1. Country code information stored incorrectly at a particular geographic latitude range. 2. Incorrect reference data when the vehicle is started and a GPS signal is not immediately available. Remedy Update head unit software to latest version and the re‑check function in the same location. If vehicle is still exhibiting one of the symptoms as described exactly as in the complaint section or as shown in the video attachments, open a TIPS case to the Body/Chassis/Entertainment inbox with the following: • Video of the concern. • Exact location (latitude and longitude is best)
LI54.65-P-080132
Service Bulletin/Repair Instructions
Complaint 1. General Diagnostic Tips 2. One or More PARK Sensor Activations 3. Red Ring Around Vehicle 4. "Active Parking and Parking Assist Inoperative" on Instrument Cluster 5. Cameras 6. Other Park Topics. Cause Various root causes Remedy See attached diagnostic guide.
LI82.62-P-078631
Service Bulletin/Repair Instructions
Complaint Clanking noise from the area of the speakers in the doors. Cause Under analysis. Remedy To narrow down the cause, first of all remove the door trim. • If the noise continues to occur even with the door trim removed, then continue the diagnosis working towards the speaker and if necessary, create a TIPS case with an informative video as an attachment. Information: Please refer to this document in the warranty claim and, after completing diagnosis, select the damage code corresponding to the component part that caused the problem. • If the noise stops when the door trim is removed, please proceed in accordance with LI72.10-P-067691. Information: In this case, do not use a damage code for the speakers in the warranty claim!
LI54.21-P-080326
Service Bulletin/Repair Instructions
Complaint CEL light on with no drivability concerns. Cause Signal timing error. Remedy 167, 465: SW has been released. Update the FSAM to the latest SW version. 290, 118, 243, 247: Software is still in development. This fault code does not cause a drivability concern and will clear itself within 2-3 key cycles. The vehicle can be released back to the customer.
LI40.10-P-059248
Service Bulletin/Repair Instructions
Complaint Crackling and cracking noise from the outer wheel on the front axle when cornering Cause The noise is generated by a micromovement on the contact surface between the rim and the brake disk (wheel bolt group) and may be intensified by potential soiling. The more lightweight rim (AMG forged rim) transmits the noise louder; in the case of cast rims, the noise is generally not perceptible. This is not a technical defect, but rather a complaint concerning comfort. Safe operation of the vehicle is ensured at all times. Remedy Important note: The operations described below do not represent a permanent remedy in every case. The noise may reoccur again after an indefinite period of time; sanding the rims with abrasive media multiple times is not permissible. Only cleaning using the Hazet tool 4960-160 (recommendation) can be performed without any concerns each time the wheel is changed or if the complaint reoccurs. Replacing the parts (rim, wheel bolts, wheel bearings, wheel hub, brake disk) is not expedient in the event of this complaint. ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Clean the components of the wheel bolt connection according to the WIS instructions Sand down the rim and brake disk bowl by performing the following steps: • Manually sand rim (old design only) in area of water drain bores (Figure 1; item A), approx. 1.5 cm left and right of water drain bore (Figure 2) Note: Use abrasive paper with grit size 80. The grooving in this area should no longer be visible (sand down approx. 0.1-0.2mm) • Also sand brake disk bowl using emery cloth or abrasive paper with a grain size of 120 • For vehicles equipped with the AMG ceramic brake system (B07), abrasive paper may not be used for cleaning on the brake disk side Note: Do not use any cleaning agent when cleaning on the rim side. Cleaning using abrasive paper with a grain size of 80 will suffice. Do not apply any grease, lubricant or paste after cleaning The brake disk bowl should be "bare metal" in the area of the imprints made by the hole (Figure 3)
LI35.30-P-058566
Service Bulletin/Repair Instructions
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).
LI33.20-P-078406
Service Bulletin/Repair Instructions
Complaint Creaking noise, in irregular sequence when driving slowly in combination with slight steering movements and/or Creaking/crackling noises from the area of the wheel bearing on the front axle when cornering/ maneuvering. Sound file attached for comparison. MUST match noise for proper diagnosis. NOTE: Steering functionality is not affected. Cause Contact area between wheel bearing and steering knuckle. See also: LI35.30-P-058566 (Throttle Lift-Off Noise - Rear) LI33.30-P-056665 (Throttle Lift-Off Noise - Front) LI40.10-P-059248 (Wheel cracking noise when cornering) Remedy 1. Perform Operation A and evaluate by testing vehicle. 2. If noise is still present after re-testing: • If 192/232 chassis, verify FIN is in the listed range below in "Operation B" and perform. • If not 192/232 chassis or vehicle is a 192/232 not in the listed FIN range, additional verifications of where the noise is coming from are needed. Use multiple channel NVH method to narrow down location. Verify the LI's listed above were completed or if there are other similar noises associated with the chassis (Example: 192/232 also has under panel noises and an associated LI). Operation A: 1. Clean contact surfaces of wheel bearing and steering knuckle with brake cleaner as seen in the attached pictures. NOTE: The front area of the wheel bearing and the seals must not come into contact with the cleaner, otherwise, the sealing rings will be damaged. 2. Clean threads of wheel bearing mounting. 3. Thinly coat contact surfaces of wheel bearing, steering knuckle, and axle mating face with Molykote (annular joint grease). See the attached steering knuckle and wheel hub pictures for reference. NOTE: Axle mating face greasing is also covered in LI35.30-P-058566 and LI33.30-P-056665. Operation B (Only applies to 192 and 232 in listed FIN range): Only affects vehicles up to FIN end number: • Model series 192: xxx xxx xx 002 876 • Model series 232: xxx xxx xx 022 312 1. Replace steering knuckle. 2. Wheel bearings do not need to be replaced.
LI82.60-P-080383
Service Bulletin/Repair Instructions
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. The E505.9 software is released and available in XENTRY Q3 2026.
PSL-NCU Return Parts 7/3
Other
Dear Mercedes-Benz USA Dealers, The part numbers listed in the chart below should no longer be installed, and any existing stock must be returned to your facing PDC. The deadline for all dealer returns is no later than Thursday, July 23rd, 2026. After July 23rd, 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.
LI00.20-P-077615
Service Bulletin/Repair Instructions
Complaint 1. "Perform vehicle handover" in the workshop menu to start the maintenance computer for service A/B cannot be carried out. 2. Service confirmation is not possible because "Perform vehicle handover" is displayed. This cannot be carried out. 3. The service display in the instrument cluster permanently displays 365 days (remaining time) and does not change. Cause Routine change in the software in N133/1 (instrument cluster) or A26/17 (MBUX multimedia system and instrument cluster (head unit)). Vehicle handover was not performed. Remedy For model series 290 AMG up to and including AEJ 22 and model series 167 up to and including AEJ 21/2, the following applies: Manually commission already-installed instrument cluster control unit N133/1 and then perform special procedure to re-initialize ASSYST data in N127 powertrain control unit. The following applies to model series 167 from AEJ 22/1 onward, 192 AMG, 206, 214, 223, 232 AMG, 236, 254, 290 AMG from AEJ 23 onward, 294, 295, 296, 297 and 465: Reinitialize ASSYST Plus under Adaptations – Teach-in processes – ASSYST PLUS in control unit N133/1 (instrument cluster) or A26/17 (MBUX multimedia system and instrument cluster (head unit)), and then perform the special procedure for reinitializing the ASSYST data in powertrain control unit N127.
LI00.20-P-080703
Service Bulletin/Repair Instructions
Complaint Service code B1 displayed in the customer menu does not match the workshop code displayed in the workshop menu, e.g., 505 or 550A, which includes a service A. Cause The root cause is currently being investigated. Remedy To determine the cause, the instrument cluster control unit (N133/1) and powertrain control unit (N127) logs are required before confirming the service or correction using XENTRY Diagnosis. Please open a TIPS case to BCE inbox with the requested information in the attachments.
LI32.34-P-080645
Service Bulletin/Repair Instructions
Complaint Rattle or clunking noise from underneath the vehicle when driving over uneven/bumpy surfaces. Cause Internal tolerances of the electric rollbar. Remedy 1. Confirm front or rear roll bar. 2. Remove the affected sway bar links and carefully drive vehicle. • Noise not resolved with sway bar links removed > Not appliable to this LI, noise is from a different component. • Noise resolved with sway bar links removed > Current parts may make some noise and is currently state of the art. Optimized, quieter parts will be available Q4 2026, please release vehicle until such time parts are available. For further questions, inquiries, or sound levels approximately equal to or above what is shown in the attachment, open a TIPS case to the Body, Chassis, Entertainment inbox.
LI82.85-P-080507
Service Bulletin/Repair Instructions
Complaint After successful commissioning of the HERMES control unit (N112/9) with XENTRY Diagnosis DVD 03/2026, the message "SOS - service not activated" appears on the instrument cluster. In addition, the following two conditions are also met: • HERMES (N112/9) control unit: event code B15CE00 is ACTIVE and STORED (A+S) • Vehicle Documentation System: For the HERMES control unit, the EID1, EID2, ICCID, IMEI, IMSI, TELNR fields in the "Identification/Serial number" column have the value "-" Cause Still under analysis Remedy Recommission the HERMES control unit (N112/9) with XENTRY Diagnosis 03/2026 and add-on 33399 installed or carry out the procedure with a newer version of XENTRY Diagnosis: XENTRY→ "N112/9 - Control unit for telematics services (HERMES)" -> "Adaptations" -> "Control unit commissioning" -> "Commissioning of previously installed control unit"