Mercedes-Benz C-Class Service Bulletins (2019)
237 manufacturer communications on file.
- July 24, 2026•Document ID: 11035234Service Bulletin/Repair InstructionsENGINE
- Mfr Comm. #:
- LI20.10-P-072886
- Date Added:
- July 27, 2026
- Manufacturer:
- MERCEDES-BENZ
SummaryComplaint Check Engine Light ON with DTC P012800 "The Coolant Temperature is Below the Specified Temperature" active and/or stored in the ME (N3/10). There are no drivability concerns related to this complaint. Cause Root cause varies Remedy Prior to performing any repairs for this complaint: With a cold engine, pressurize the high temp coolant circuit and while it's under pressure, release the cap on the low temp coolant circuit and check if the pressure drops right away or not. If the pressure drops, the lower coolant hoses are swapped. Correct this, fill, bleed and test drive the vehicle. If the complaint returns, then continue with the steps below. IMPORTANT: Use VMI to check for the following emission extended warranty –> Engine Thermostat (incl. software update) MY19-23, Various Models and Platforms (167, 190, 205, 213, 217, 222, 223, 232, 253, 290, 463) If the vehicle is covered under the above emission extended warranty, please perform steps outlined in the accompanying NCU prior to those outlined in this document. If vehicle is not covered under the above emission extended warranty or the complaint continues to occur, then proceed as follows: Check for available software updates to the ME (N3/10). If updated software is available, perform the update, clear the DTC and the perform each of the "WARM START" and "COLD START" test drives listed below twice. If the code does not re-appear then release the vehicle. If there is no new software available OR the DTC returns after the test drives then perform the following steps: • Drain the coolant through a fine mesh sieve and check for signs of debris. Additionally, inspect the coolant reservoir for debris. If any debris is found take pictures of the reservoir and the mesh filter and "flush" the system at least 2-3 times to clear as much of the debris as possible • Replace the thermostat and bleed the system as outlined in AR20.00-P-1142-04A, evacuate the system for 20-30 minutes instead of the 5 minutes specified in step 22 • NOTE: Please use all the tools specified in the AR document. The DTC will continue to populate if the circuit is not properly bled • NOTE: There are two valid thermostats to choose from in the parts section of this LI. Please verify which PN is applicable for the vehicle being worked on via XENTRY Parts Information • After bleeding the system clear the DTC and perform each of the "WARM START" and "COLD START" test drives listed below twice. If the DTC does not reappear after the tests, release the vehicle If the ME (N3/10) software is up to date, the thermostat has already been replaced, and the complaint persists open a TIPS case and attach the following documents: • Initial quick test • ME (N3/10) control unit log • The results of an R48 test from a “yes” response and from a “no” response • Pictures of the coolant reservoir and mesh sieve (mentioned above) WARM START · Begin with the engine coolant temperature at approximately 50 degrees C · Activate the AC system, if defrost is not in use open the windows · Drive the car normally until a coolant temperature of 75 degrees C is achieved · Depress the accelerator pedal 50% for ~5 seconds (partial acceleration) · Let off the accelerator pedal and let the car coast for ~10 seconds · Continue to drive the car normally COLD START · Drive for ~7 miles (normal driving) · Shut off the engine in a parking lot (or similar), wait 30 seconds, then restart and continue driving · Depress the accelerator pedal 50% for ~5 seconds (partial acceleration) · Let off the accelerator pedal and let the car coast for ~10 seconds · Continue to drive the car normally
Associated Products (72)2026 Mercedes-Benz AMG GT2026 Mercedes-Benz GLC-Class2026 Mercedes-Benz GLS-Class2026 Mercedes-Benz S-Class2026 Mercedes-Benz SL-Class2025 Mercedes-Benz AMG GT2025 Mercedes-Benz GLC-Class2025 Mercedes-Benz GLE-Class2025 Mercedes-Benz GLS-Class2025 Mercedes-Benz S-Class2025 Mercedes-Benz SL-Class2024 Mercedes-Benz AMG GT2024 Mercedes-Benz G-Class2024 Mercedes-Benz GLC-Class2024 Mercedes-Benz GLE-Class2024 Mercedes-Benz GLS-Class2024 Mercedes-Benz S-Class2024 Mercedes-Benz SL-Class2023 Mercedes-Benz AMG GT2023 Mercedes-Benz C-Class+ 52 moreAssociated Documents - July 21, 2026•Document ID: 11035214Service Bulletin/Repair InstructionsSTRUCTURE:BODY; WHEELS
- Mfr Comm. #:
- LI40.10-P-059248
- Date Added:
- July 24, 2026
- Manufacturer:
- MERCEDES-BENZ
SummaryComplaint 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)
Associated Products (54)2026 Mercedes-Benz AMG GT2026 Mercedes-Benz S-Class2026 Mercedes-Benz SL-Class2025 Mercedes-Benz AMG GT2025 Mercedes-Benz GLE-Class2025 Mercedes-Benz S-Class2025 Mercedes-Benz SL-Class2024 Mercedes-Benz AMG GT2024 Mercedes-Benz GLE-Class2024 Mercedes-Benz S-Class2024 Mercedes-Benz SL-Class2023 Mercedes-Benz AMG GT2023 Mercedes-Benz C-Class2023 Mercedes-Benz GLC-Class2023 Mercedes-Benz GLE-Class2023 Mercedes-Benz S-Class2023 Mercedes-Benz SL-Class2022 Mercedes-Benz AMG GT2022 Mercedes-Benz C-Class2022 Mercedes-Benz GLC-Class+ 34 moreAssociated Documents - July 14, 2026•Document ID: 11035005Service Bulletin/Repair InstructionsPOWER TRAIN
- Mfr Comm. #:
- LI35.30-P-058566
- Date Added:
- July 14, 2026
- Manufacturer:
- MERCEDES-BENZ
SummarySingle 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).
Associated Products (287)2027 Mercedes-Benz CLA-Class2026 Mercedes-Benz AMG GT2026 Mercedes-Benz C-Class2026 Mercedes-Benz CLA-Class2026 Mercedes-Benz CLE2026 Mercedes-Benz E-Class2026 Mercedes-Benz GLA-Class2026 Mercedes-Benz GLB-Class2026 Mercedes-Benz GLC-Class2026 Mercedes-Benz GLE-Class2026 Mercedes-Benz GLS-Class2026 Mercedes-Benz S-Class2026 Mercedes-Benz SL-Class2025 Mercedes-Benz AMG GT2025 Mercedes-Benz C-Class2025 Mercedes-Benz CLA-Class2025 Mercedes-Benz CLE2025 Mercedes-Benz E-Class2025 Mercedes-Benz EQB-Class2025 Mercedes-Benz G-Class+ 267 moreAssociated Documents - July 8, 2026•Document ID: 11035003Service Bulletin/Repair InstructionsSUSPENSION
- Mfr Comm. #:
- LI33.20-P-078406
- Date Added:
- July 14, 2026
- Manufacturer:
- MERCEDES-BENZ
SummaryComplaint 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.
Associated Products (97)2026 Mercedes-Benz AMG GT2026 Mercedes-Benz C-Class2026 Mercedes-Benz CLE2026 Mercedes-Benz E-Class2026 Mercedes-Benz GLC-Class2026 Mercedes-Benz GLE-Class2026 Mercedes-Benz S-Class2026 Mercedes-Benz SL-Class2025 Mercedes-Benz AMG GT2025 Mercedes-Benz C-Class2025 Mercedes-Benz CLE2025 Mercedes-Benz E-Class2025 Mercedes-Benz GLC-Class2025 Mercedes-Benz GLE-Class2025 Mercedes-Benz S-Class2025 Mercedes-Benz SL-Class2024 Mercedes-Benz AMG GT2024 Mercedes-Benz C-Class2024 Mercedes-Benz CLE2024 Mercedes-Benz E-Class+ 77 moreAssociated Documents - June 19, 2026•Document ID: 11034064OtherVISIBILITY/WIPER; ENGINE
- Mfr Comm. #:
- PSL-NCU Return Parts 6/19
- Date Added:
- June 25, 2026
- Manufacturer:
- MERCEDES-BENZ
SummaryDear 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 9, 2026. After July 9th, 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.
Associated Products (82)2026 Mercedes-Benz AMG GT2026 Mercedes-Benz GLA-Class2026 Mercedes-Benz GLB-Class2026 Mercedes-Benz S-Class2025 Mercedes-Benz AMG GT2025 Mercedes-Benz GLA-Class2025 Mercedes-Benz GLB-Class2025 Mercedes-Benz S-Class2024 Mercedes-Benz AMG GT2024 Mercedes-Benz GLA-Class2024 Mercedes-Benz GLB-Class2024 Mercedes-Benz S-Class2023 Mercedes-Benz AMG GT2023 Mercedes-Benz C-Class2023 Mercedes-Benz E-Class2023 Mercedes-Benz GLA-Class2023 Mercedes-Benz GLB-Class2023 Mercedes-Benz GLC-Class2023 Mercedes-Benz S-Class2022 Mercedes-Benz A-Class+ 62 moreAssociated Documents - June 12, 2026•Document ID: 11033855Service Bulletin/Repair InstructionsELECTRICAL SYSTEM
- Mfr Comm. #:
- LI00.20-P-080703
- Date Added:
- June 16, 2026
- Manufacturer:
- MERCEDES-BENZ
SummaryComplaint 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.
Associated Products (97)2027 Mercedes-Benz CLA-Class2026 Mercedes-Benz AMG GT2026 Mercedes-Benz CLA-Class2026 Mercedes-Benz GLA-Class2026 Mercedes-Benz GLB-Class2026 Mercedes-Benz GLE-Class2026 Mercedes-Benz GLS-Class2025 Mercedes-Benz AMG GT2025 Mercedes-Benz CLA-Class2025 Mercedes-Benz EQB-Class2025 Mercedes-Benz G-Class2025 Mercedes-Benz GLA-Class2025 Mercedes-Benz GLB-Class2025 Mercedes-Benz GLE-Class2025 Mercedes-Benz GLS-Class2024 Mercedes-Benz AMG GT2024 Mercedes-Benz CLA-Class2024 Mercedes-Benz EQB-Class2024 Mercedes-Benz G-Class2024 Mercedes-Benz GLA-Class+ 77 moreAssociated Documents - May 26, 2026•Document ID: 11033185Service Bulletin/Repair InstructionsELECTRICAL SYSTEM
- Mfr Comm. #:
- LI82.85-P-080507
- Date Added:
- June 2, 2026
- Manufacturer:
- MERCEDES-BENZ
SummaryComplaint 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"
Associated Products (175)2026 Mercedes-Benz C-Class2026 Mercedes-Benz CLA-Class2026 Mercedes-Benz GLA-Class2026 Mercedes-Benz GLB-Class2026 Mercedes-Benz GLE-Class2026 Mercedes-Benz GLS-Class2025 Mercedes-Benz C-Class2025 Mercedes-Benz CLA-Class2025 Mercedes-Benz EQB-Class2025 Mercedes-Benz G-Class2025 Mercedes-Benz GLA-Class2025 Mercedes-Benz GLB-Class2025 Mercedes-Benz GLE-Class2025 Mercedes-Benz GLS-Class2024 Mercedes-Benz C-Class2024 Mercedes-Benz CLA-Class2024 Mercedes-Benz EQB-Class2024 Mercedes-Benz G-Class2024 Mercedes-Benz GLA-Class2024 Mercedes-Benz GLB-Class+ 155 moreAssociated Documents - May 26, 2026•Document ID: 11033016Service Bulletin/Repair InstructionsELECTRICAL SYSTEM
- Mfr Comm. #:
- LI82.85-P-080559
- Date Added:
- May 29, 2026
- Manufacturer:
- MERCEDES-BENZ
SummaryComplaint The customer requests deactivation of the N112/9 HERMES communication module Note: Deactivation of the HERMES control unit (N112/9) is not supported for gray-market vehicles. Cause Before deactivating the HERMES control unit (N112/9), it must be clarified by the legal department of the respective MPC whether and under what conditions deactivation may be carried out. If deactivation is not permissible under applicable law, the HERMES control unit (N112/9) must not be deactivated. Remedy Please inform the customer that, following deactivation, the vehicle will no longer be able to place an automatic emergency call, nor will the customer be able to place a manual emergency call. After deactivation, the Mercedes-Benz Digital Extras will also no longer be available. Please have the attached sample form checked by your market's legal department, adapted to local requirements if necessary, and approved. Furthermore, after informing the customer about the effects of deactivation, please have the workshop complete and sign the approved form together with the customer, and send it to the MPC via a TIPS case for audit-compliant documentation. Furthermore, the workshop must affix a sticker to the emergency call button cover on the overhead control panel and to the emergency call button itself. After affixing, pictures of the overhead control panel need to be attached to the TIPS case for audit-proof documentation. After deactivation, the HERMES control unit (N112/9) is in the "Out of Service" operating status, and the display "SOS NOT READY" appears in the Audio/COMAND system. This display message tells the customer that the emergency call function is not available. In detail, the following steps must be carried out 1. The workshop must inform the customer about the effects of deactivation (see above) 2. Legal review by the MPC Legal department to determine whether deactivation is permissible for the vehicle and provision of a market-specific customer form based on the examples (see "Example - Deactivation communication module HERMES customer declaration English V3.0.pdf") 3. Completion of the market-specific customer form by the workshop and obtaining the customer’s signature 4. Creation of a XSS ticket by the workshop for the MPC with the signed customer form attached 5. Written confirmation of legally reviewed and approved deactivation by the MPC in the TIPS case (see attachment How+to+request+adding+Code+09o+via+XSS+v2.pdf, point 1) 6. Creation of an XSS ticket for documentation of the SA code "09o" (zero nine oh) in the Vehicle Documentation System (see attachment How+to+request+adding+Code+09o+via+XSS+v2.pdf, steps 2–7) 7. Ordering of stickers (part number A9078172900), quantity: 2 8. Affixing of the sticker (part number A9078172900) to the cover of the emergency call button on the overhead control panel (see attachment HERMES-Deactivation_+pictures+of+sticker.png) 9. Affixing of the sticker (part number A9078172900) to the emergency call button on the overhead control panel (see attachment HERMES-Deactivation_+pictures+of+sticker.png) 10. Taking photos of the applied stickers and attaching them to the TIPS case 11. After the XSS ticket has been successfully processed, the communication module must be deactivated using XENTRY: • Connect XENTRY Diagnosis • Access the HERMES control unit (N112/9) • "Adaptation" tab, menu item "Teach-in processes" -> "Deactivation" • Follow the instructions
Associated Products (94)2023 Mercedes-Benz C-Class2023 Mercedes-Benz CLS-Class2023 Mercedes-Benz E-Class2023 Mercedes-Benz GLC-Class2022 Mercedes-Benz A-Class2022 Mercedes-Benz C-Class2022 Mercedes-Benz CLS-Class2022 Mercedes-Benz E-Class2022 Mercedes-Benz GLC-Class2021 Mercedes-Benz A-Class2021 Mercedes-Benz AMG GT2021 Mercedes-Benz C-Class2021 Mercedes-Benz CLS-Class2021 Mercedes-Benz E-Class2021 Mercedes-Benz GLC-Class2021 Mercedes-Benz S-Class2020 Mercedes-Benz A-Class2020 Mercedes-Benz AMG GT2020 Mercedes-Benz C-Class2020 Mercedes-Benz CLS-Class+ 74 moreAssociated Documents - May 22, 2026•Document ID: 11033050OtherPOWER TRAIN; STRUCTURE:BODY
- Mfr Comm. #:
- PSL-NCU Return Parts 5/22
- Date Added:
- June 1, 2026
- Manufacturer:
- MERCEDES-BENZ
SummaryDear 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.
Associated Products (95)2026 Mercedes-Benz GLC-Class2025 Mercedes-Benz AMG GT2025 Mercedes-Benz C-Class2025 Mercedes-Benz GLC-Class2025 Mercedes-Benz GLE-Class2025 Mercedes-Benz GLS-Class2025 Mercedes-Benz S-Class2025 Mercedes-Benz SL-Class2024 Mercedes-Benz AMG GT2024 Mercedes-Benz C-Class2024 Mercedes-Benz G-Class2024 Mercedes-Benz GLE-Class2024 Mercedes-Benz GLS-Class2024 Mercedes-Benz S-Class2024 Mercedes-Benz SL-Class2023 Mercedes-Benz AMG GT2023 Mercedes-Benz C-Class2023 Mercedes-Benz CLS-Class2023 Mercedes-Benz E-Class2023 Mercedes-Benz G-Class+ 75 moreAssociated Documents - May 19, 2026•Document ID: 11032875Service Bulletin/Repair InstructionsVISIBILITY/WIPER
- Mfr Comm. #:
- LI82.30-P-059239
- Date Added:
- May 20, 2026
- Manufacturer:
- MERCEDES-BENZ
SummaryComplaint There are several types of complaint about noises or poor windshield wiper wiping performance: A: Wiper blades squeaking, chattering, shuddering B: The windshield is not wiped completely (streaking) C: During the downward movement water is pulled back onto the windshield from the A-pillar (Figure 1) D: After windshield cleaning, water keeps spraying onto the windshield for several wipe cycles (Figure 2) A1: The windshield and wiper blades are contaminated with residues from car washing facilities, identifiable by the water beading. The resulting differences in the friction values between the wiper blades and the windshield can excite the wiper blades to vibrate. Note: It is mostly wax residue from the washer system, but also water-repellent nano-particle coating for paint and/or silicone-based washer fluid, that could cause this problem. A partially dry windshield also has different friction values, which can likewise result in squeaking of the wiper blades A2: The wiper blades are worn by mechanical damage (wiper lip damaged by ice or insect debris, or deformed by long periods of disuse). A3: Incorrect angle of incidence of the wiper arms to the windshield. Because of this, the rubber lip of the wiper blade may not flip over at the reversal point. Cause B: B1: Wax/ dirt residues on the windshield B2: Wiper blades deformed or worn B3: Downforce of wiper arm not OK (Figure 3) Cause C: Water is pulled back onto the windshield by the differential pressure created as the wiper arm moves downwards. Cause D: Washer water collects in the fastening of the wiper blade and is blown onto the windshield by the airstream over several wipe cycles. Note and supporting information: Wiper blades are wear parts which, even when "not used" for long periods (kept in park position), may become permanently deformed and damaged. Further stresses on the rubber wiper blade arise due to various environmental influences which progressively change the effectiveness of the rubber wiper blade and accelerate the aging process. Due to the natural aging process and wear, the wiper blades should be replaced twice a year, preferably in Spring and Fall (see operator's manual). Remedy Remedy A: A1: Cleaning entire windshield with A 000 986 40 71. A2: Checking water's flow behavior after windshield has been cleaned (see Video 1). If, after cleaning, there are still areas with water beading, then the cleaning process must be carried out again until a rejection reaction is no longer present. • Note: On the vehicle in the video (Video 1), water still beads on the bottom left of the windshield. The windshield is still not properly clean, even though it appears to be clean. The windshield is only properly clean when there are no more areas on the windshield where water beads. A3: Replace wiper blades with genuine wiper blades. Important: Only exchange wiper blades if windshield no longer has water-repellent areas Note: Replacement of wiper blades is not covered under warranty and can be replaced at the expense of the customer. Remedy B: B1: Clean windshield with intensive cleaner A 000 986 40 71. Important: Do not clean the wiper blades otherwise the graphite coating will be damaged. B2: Replace wiper blades with genuine wiper blades • Note: Replacement of wiper blades is not covered under warranty and can be replaced at the expense of the customer. B3: Check the wiper arm for excessive resistance in the bearing. Restore mobility or replace wiper arm if necessary. Remedy C: Problem inherent in design for which there is no technical remedy. Exception: X204 up to 02/2014. In these vehicles, it is possible to install the design configuration of vehicles as of 02/2014. This includes wiper arms (styled arms) with improved behavior in this respect. It is also necessary to replace the wiper blades because the styled arms feature a Top Lock connection (previously Side Lock).
Associated Products (221)2027 Mercedes-Benz CLA-Class2026 Mercedes-Benz AMG GT2026 Mercedes-Benz C-Class2026 Mercedes-Benz CLA-Class2026 Mercedes-Benz CLE2026 Mercedes-Benz E-Class2026 Mercedes-Benz GLA-Class2026 Mercedes-Benz GLB-Class2026 Mercedes-Benz GLC-Class2026 Mercedes-Benz GLE-Class2026 Mercedes-Benz S-Class2026 Mercedes-Benz SL-Class2025 Mercedes-Benz AMG GT2025 Mercedes-Benz C-Class2025 Mercedes-Benz CLA-Class2025 Mercedes-Benz CLE2025 Mercedes-Benz E-Class2025 Mercedes-Benz GLA-Class2025 Mercedes-Benz GLB-Class2025 Mercedes-Benz GLC-Class+ 201 moreAssociated Documents - May 18, 2026•Document ID: 11032873Service Bulletin/Repair InstructionsENGINE
- Mfr Comm. #:
- LI07.10-P-080384
- Date Added:
- May 20, 2026
- Manufacturer:
- MERCEDES-BENZ
SummaryComplaint Customer reports Check Engine Light with possible loss of power concern. The Following DTC's are present • P210185 - The throttle valve actuator has a malfunction. There is a signal above the permissible limit value. • P213500 - The values from the position sensors of the throttle valve are implausible relative to each other • P213600 - The values from position sensors "A/C" of the throttle valve are implausible relative to each other • P210B85 - The throttle valve actuator 2 has a malfunction. There is a signal above the permissible limit value. • P2AD300 - The values from the position sensors "A/G" of the throttle valve are implausible relative to each other Cause Increased electrical resistance in pins for left and right throttle actuators. (M16/60 and M16/61) Remedy Replaced left and right throttle actuator Sockets with updated part. Silver Coated Pins 8x A 003 982 70 26 (according to wiring diagram 0,5mm) Gold Coated Pins 4x A 003 982 75 26 (according to wiring diagram 0,75mm) ELA Seals 12x A 001 545 50 80
Associated Products (63)2026 Mercedes-Benz AMG GT2026 Mercedes-Benz GLC-Class2026 Mercedes-Benz S-Class2026 Mercedes-Benz SL-Class2025 Mercedes-Benz AMG GT2025 Mercedes-Benz GLC-Class2025 Mercedes-Benz GLE-Class2025 Mercedes-Benz GLS-Class2025 Mercedes-Benz S-Class2025 Mercedes-Benz SL-Class2024 Mercedes-Benz AMG GT2024 Mercedes-Benz G-Class2024 Mercedes-Benz GLC-Class2024 Mercedes-Benz GLE-Class2024 Mercedes-Benz GLS-Class2024 Mercedes-Benz S-Class2024 Mercedes-Benz SL-Class2023 Mercedes-Benz AMG GT2023 Mercedes-Benz C-Class2023 Mercedes-Benz E-Class+ 43 moreAssociated Documents - May 15, 2026•Document ID: 11032751Service Bulletin/Repair InstructionsSUSPENSION; WHEELS
- Mfr Comm. #:
- LI40.10-P-061032
- Date Added:
- May 18, 2026
- Manufacturer:
- MERCEDES-BENZ
SummaryComplaint Noises at the front axle when cornering or maneuvering (video files attached) Note: Save video files locally and play them with Windows Media Player. Cause Driving with summer tires in combination with low outside temperatures. At low outside temperatures or in wet conditions, a noise may be produced at the outer wheel on the front axle while maneuvering with sharp steering angles. Note: AMG vehicles with 4MATIC of model series 217 (without code 494) and model series 222 have a modified axle geometry compared with series production vehicles to provide more sporty handling. The problem cannot be remedied by changing the axle settings.
Associated Products (165)2026 Mercedes-Benz AMG GT2026 Mercedes-Benz C-Class2026 Mercedes-Benz CLA-Class2026 Mercedes-Benz E-Class2026 Mercedes-Benz GLA-Class2026 Mercedes-Benz GLB-Class2026 Mercedes-Benz GLS-Class2026 Mercedes-Benz S-Class2026 Mercedes-Benz SL-Class2025 Mercedes-Benz AMG GT2025 Mercedes-Benz C-Class2025 Mercedes-Benz E-Class2025 Mercedes-Benz GLA-Class2025 Mercedes-Benz GLB-Class2025 Mercedes-Benz GLE-Class2025 Mercedes-Benz GLS-Class2025 Mercedes-Benz S-Class2025 Mercedes-Benz SL-Class2024 Mercedes-Benz AMG GT2024 Mercedes-Benz C-Class+ 145 moreAssociated Documents - May 15, 2026•Document ID: 11032736OtherSUSPENSION; POWER TRAIN
- Mfr Comm. #:
- PSL-NCU Return Parts 5/15
- Date Added:
- May 18, 2026
- Manufacturer:
- MERCEDES-BENZ
SummaryThe 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.
Associated Products (95)2026 Mercedes-Benz AMG GT2026 Mercedes-Benz SL-Class2025 Mercedes-Benz AMG GT2025 Mercedes-Benz C-Class2025 Mercedes-Benz GLE-Class2025 Mercedes-Benz GLS-Class2025 Mercedes-Benz S-Class2025 Mercedes-Benz SL-Class2024 Mercedes-Benz AMG GT2024 Mercedes-Benz C-Class2024 Mercedes-Benz G-Class2024 Mercedes-Benz GLE-Class2024 Mercedes-Benz GLS-Class2024 Mercedes-Benz S-Class2024 Mercedes-Benz SL-Class2023 Mercedes-Benz AMG GT2023 Mercedes-Benz C-Class2023 Mercedes-Benz CLS-Class2023 Mercedes-Benz E-Class2023 Mercedes-Benz G-Class+ 75 moreAssociated Documents - May 12, 2026•Document ID: 11032699Service Bulletin/Repair InstructionsBACK OVER PREVENTION: WARNINGS; LANE DEPARTURE: BLIND SPOT DETECTION; ELECTRICAL SYSTEM
- Mfr Comm. #:
- LI54.65-P-080132
- Date Added:
- May 14, 2026
- Manufacturer:
- MERCEDES-BENZ
SummaryComplaint 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.
Associated Products (117)2027 Mercedes-Benz CLA-Class2026 Mercedes-Benz AMG GT2026 Mercedes-Benz C-Class2026 Mercedes-Benz CLA-Class2026 Mercedes-Benz CLE2026 Mercedes-Benz E-Class2026 Mercedes-Benz GLA-Class2026 Mercedes-Benz GLB-Class2026 Mercedes-Benz GLC-Class2026 Mercedes-Benz GLE-Class2026 Mercedes-Benz GLS-Class2026 Mercedes-Benz S-Class2026 Mercedes-Benz SL-Class2025 Mercedes-Benz AMG GT2025 Mercedes-Benz C-Class2025 Mercedes-Benz CLA-Class2025 Mercedes-Benz CLE2025 Mercedes-Benz E-Class2025 Mercedes-Benz EQB-Class2025 Mercedes-Benz G-Class+ 97 moreAssociated Documents - April 28, 2026•Document ID: 11031698Service Bulletin/Repair InstructionsENGINE
- Mfr Comm. #:
- LI07.10-P-080384
- Date Added:
- April 29, 2026
- Manufacturer:
- MERCEDES-BENZ
SummaryComplaint Customer reports Check Engine Light with possible loss of power concern. The Following DTC's are present • P210185 - The throttle valve actuator has a malfunction. There is a signal above the permissible limit value. • P213500 - The values from the position sensors of the throttle valve are implausible relative to each other • P213600 - The values from position sensors "A/C" of the throttle valve are implausible relative to each other Cause Increased electrical resistance in pins for left and right throttle actuators. (M16/60 and M16/61) Remedy Replaced left and right throttle actuator Sockets with updated part. Silver Coated Pins 8x A 003 982 70 26 (according to wiring diagram 0,5mm) 4x A 003 982 75 26 (according to wiring diagram 0,75mm) ELA Seals 12x A 001 545 50 80
Associated Products (59)2026 Mercedes-Benz AMG GT2026 Mercedes-Benz SL-Class2025 Mercedes-Benz AMG GT2025 Mercedes-Benz GLE-Class2025 Mercedes-Benz GLS-Class2025 Mercedes-Benz S-Class2025 Mercedes-Benz SL-Class2024 Mercedes-Benz AMG GT2024 Mercedes-Benz G-Class2024 Mercedes-Benz GLE-Class2024 Mercedes-Benz GLS-Class2024 Mercedes-Benz S-Class2024 Mercedes-Benz SL-Class2023 Mercedes-Benz AMG GT2023 Mercedes-Benz C-Class2023 Mercedes-Benz E-Class2023 Mercedes-Benz G-Class2023 Mercedes-Benz GLC-Class2023 Mercedes-Benz GLE-Class2023 Mercedes-Benz GLS-Class+ 39 moreAssociated Documents - April 28, 2026•Document ID: 11031659Service Bulletin/Repair InstructionsSTRUCTURE:BODY
- Mfr Comm. #:
- LI77.30-P-070145
- Date Added:
- April 29, 2026
- Manufacturer:
- MERCEDES-BENZ
SummaryComplaint Damaged cords/tensioning cables at the soft top interior trim with the following characteristics: - Cord/tensioning cable torn - Cord/tensioning cable worn - Cord/tensioning cable torn out - Cord/tensioning cable - sheathing damaged Cause High tensile stresses on the cords/tensioning cables during the soft top sequence Remedy 1.) Check which cord(s)/tensioning cable(s) is/are damaged: • If damage is found on one of the cords/tensioning cables of the soft top interior trim, always replace the cords on the left and right as a pair. • If damage is determined at one of the cords from among no. 3 (if present), no. 4 or no. 7 from the soft top interior trim, then preventively replace all cords/tensioning cables of no. 3 (if present), no. 4 and no. 7 on the left and right. • This also applies to the new version of the soft top interior trim cords/tensioning cables for no. 4 and no. 7 (without cord/tensioning cable no. 3) on the left and right. 2.) Cut off the fastening rivets/eyelets: • See Fig. 6 - Illustrates a riveted fastening of the eyelet. See also document AR77.33-P-2500LWR - Remove/install tensioning cables of the headliner. 3.) Press the clamping ring connection out of the receptacle in the soft top interior trim: • See Fig. 7 - Illustrates the receptacle/clamping ring of the soft top interior trim. 4.) Cut/remove the clamping ring connection from the cord using side cutting pliers: • See Fig. 8 - Separating the clamping ring connection using side cutting pliers. 5.) After removing the clamping ring connection and for routing the new cord/tensioning cable: • Briefly heat the end of the new cord/tensioning cable with a lighter or similar tool. This will strengthen the fibers at the front somewhat and slightly round them off, • which will then make it easier to pull them through the duct with a cutting wire. • See Fig 9. - Slightly heating the end of the cord/tensioning cable with a lighter or similar tool 6.) Attach auxiliary cutting wire (0.3 mm or 0.8 mm) at the end of the new cord/tensioning cable: • Perforate/attach cutting wire approx. 5 mm from the end of the cord/tensioning cable. • Bend the cutting wire into shape and position the cord/tensioning cable. • See Fig. 10 – Auxiliary cutting wire. 7.) Pull the new cord/tensioning cable through the duct with the auxiliary cutting wire and, if necessary, with pliers: • See Fig. 11 – Auxiliary cutting wire/pliers. 8.) Attach the clamping ring at the cord/tensioning cable with pliers and leave the cord/tensioning cable protruding by approx. 3 mm ±1. Crush the clamping ring to a thickness of 3.75 mm ±0.25: • See Fig. 12 - Receptacle for clamping ring connection/soft top interior trim. Note/recommendation: • To facilitate the work, the pull-off device/workshop equipment W 221 589 04 33 can also be used to crush the clamping ring or the cable lug. • See Fig. 12A – Auxiliary tool/pull-off device. 9.) Press the clamping ring connection into the receptacle provided, and install the eyelet with the rivet in the intended position: • See Fig. 13 - Receptacle for clamping ring connection/soft top interior trim. • See Fig. 14 - Positioning the rivet with eyelet - example. Further information on optimizations: Due to optimization measures, all new soft top interior trim parts are manufactured without the cord/tensioning cable no. 3. In series production and in repair cases, the cord/tensioning cable no. 3 is no longer required. Therefore, in repair cases, it is only replaced if it is already present in the vehicle. All cords/tensioning cables currently used in series production and as replacement parts have a high resistance to abrasion. - Tape guide for the cords no. 3 (if present) and no. 7: • Make sure that cords/tensioning cables 3 (if present) and 7 are routed behind the tape. As a reference dimension, the tape should be positioned approx. 10 mm from the guide eyelet. • See attachment for further instructions.
Associated Products (9)Associated Documents - April 21, 2026•Document ID: 11031581Service Bulletin/Repair InstructionsENGINE
- Mfr Comm. #:
- LI20.10-P-072886
- Date Added:
- April 27, 2026
- Manufacturer:
- MERCEDES-BENZ
SummaryComplaint CEL ON with DTC P012800 "The Coolant Temperature is Below the Specified Temperature" active and stored in the ME (N3/10). There are no drivability concerns related to the complaint. Cause Root cause varies Remedy Prior to performing any repairs for this complaint: With a cold engine, pressurize the high temp coolant circuit and while it's under pressure, release the cap on the low temp coolant circuit and check if the pressure drops right away or not. If the pressure drops, the lower hoses are swapped. Correct this, fill, bleed and test drive the vehicle. If the complaint returns, then continue with the steps below. IMPORTANT: Use VMI to check for emission extended warranty – Engine Thermostat (incl. software update) MY19-23, Various Models and Platforms (167, 190, 205, 213, 217, 222, 223, 232, 253, 290, 463) If the vehicle is covered under an emission extended warranty, Please perform steps outlined in the NCU for repairs. If vehicle is not covered under an emission extended warranty, then proceed as follows: Check for available software updates to the ME (N3/10). If updated software is available, perform the update, clear the DTC and the perform each of the "WARM START" and "COLD START" test drives listed below twice. If the code does not re-appear then release the vehicle If there is no new software available OR the DTC returns after the test drives then perform the following steps: • Drain the coolant through a fine mesh sieve and check for signs of debris. Additionally, inspect the coolant reservoir for debris. If any debris is found, flush the system several times to clear as much of the debris as possible • Replace the thermostat and bleed the system as outlined in AR20.00-P-1142-04A, evacuate the system for 20-30 minutes instead of the 5 minutes specified in step 22 • NOTE: Please use all the tools specified in the AR document • NOTE: There are two valid thermostats to choose from in the parts section of this LI. Please verify which PN is applicable for the vehicle being worked on via XENTRY Parts Information • After bleeding the system clear the DTC and perform each of the "WARM START" and "COLD START" test drives listed below twice. If the DTC does not reappear after the tests, release the vehicle If there is no new software available, the thermostat has already been replaced, and the DTC returns open a TIPS case and attach the following documents: • Initial quick test • ME (N3/10) control unit log • The results of an R48 test from a “yes” response and from a “no” response WARM START · Begin with the engine coolant temperature at approximately 50 degrees C · Activate the AC system, if defrost is not in use open the windows · Drive the car normally until a coolant temperature of 75 degrees C is achieved · Depress the accelerator pedal 50% for ~5 seconds (partial acceleration) · Let off the accelerator pedal and let the car coast for ~10 seconds · Continue to drive the car normally COLD START · Drive for ~7 miles (normal driving) · Shut off the engine in a parking lot (or similar), wait 30 seconds, then restart and continue driving · Depress the accelerator pedal 50% for ~5 seconds (partial acceleration) · Let off the accelerator pedal and let the car coast for ~10 seconds · Continue to drive the car normally
Associated Products (69)2026 Mercedes-Benz AMG GT2026 Mercedes-Benz SL-Class2025 Mercedes-Benz AMG GT2025 Mercedes-Benz GLC-Class2025 Mercedes-Benz GLE-Class2025 Mercedes-Benz GLS-Class2025 Mercedes-Benz S-Class2025 Mercedes-Benz SL-Class2024 Mercedes-Benz AMG GT2024 Mercedes-Benz G-Class2024 Mercedes-Benz GLC-Class2024 Mercedes-Benz GLE-Class2024 Mercedes-Benz GLS-Class2024 Mercedes-Benz S-Class2024 Mercedes-Benz SL-Class2023 Mercedes-Benz AMG GT2023 Mercedes-Benz C-Class2023 Mercedes-Benz E-Class2023 Mercedes-Benz G-Class2023 Mercedes-Benz GLC-Class+ 49 moreAssociated Documents - April 16, 2026•Document ID: 11031580Service Bulletin/Repair InstructionsEXTERIOR LIGHTING
- Mfr Comm. #:
- LI82.10-P-078301
- Date Added:
- April 27, 2026
- Manufacturer:
- MERCEDES-BENZ
SummaryComplaint Headlamp, front fog lamp leaky or fogged. Cause Fogging of the headlamps is a natural phenomenon, which can occur under certain climatic conditions. It does not lead to any technical impairment of the headlamp. If a pressure compensation diaphragm is fitted in the housing cover, then the lamp unit is a "closed system". Remedy Headlamp: Remedy 1 Clearing fogged/condensed LED headlamps: 1. Drive vehicle into workshop (temperature higher than +18 °C/+64.4 °F) and connect the exhaust extraction. Note: Do not perform an engine wash before the defogging test. 2. Switch off the engine and connect battery support via a charger. 3. Open the hood. 4. Switch on the lights. 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 (thawing progress). Clearing of fogged/condensed LED headlamps and LED rear lamps on electric vehicles: 1. Drive the vehicle into the workshop (temperature higher than +18 °C/+64.4°F). 2. Connect battery backup via a charger. 3. Open the front-end flap and ensure sufficient ventilation. 4. Switch on the lights. 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 (thawing progress). Clearing fogged/condensed halogen/xenon headlamps: 1. Drive the vehicle into the workshop (temperature higher than +18 °C/+64.4°F). Note: Do not perform an engine wash before the defogging test. 2. Switch off the engine. 3. Open the hood. 4. Switch off the lights. 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 (thawing progress). Note: If there is no visible reduction in condensation, check the headlamp for malfunctions. (see Remedy 2) It is not physically possible to defog the headlamps completely. Fogging does not impair the operation or the service life of the headlamp. Note: Only implement Remedy 1 for model series 463 (from model year 2018) and model series 465. Remedy 2 A defective headlamp can be identified as follows: 1. Check the headlamp for external damage and that the cover caps and the diaphragm are correctly seated. 2. Check the electrical connectors of the plugs and pins. 3. Check for leak tightness according to LI82.10-P-078307. The test can only be conducted on headlamps. 4. If the headlamp or the rear lamp has any external damage, replace the component part in accordance with the WIS instructions. Note: External damage to the headlamp/rear lamp or faulty seating of the cover caps does not present a warranty or goodwill case. Note: With headlamps, it is possible to install desiccant packs if the problem occurs repeatedly. • Open ventilation system LI82.10-P-078302 • Closed ventilation system LI82.10-P-078304
Associated Products (285)2026 Mercedes-Benz AMG GT2026 Mercedes-Benz C-Class2026 Mercedes-Benz CLA-Class2026 Mercedes-Benz CLE2026 Mercedes-Benz E-Class2026 Mercedes-Benz GLA-Class2026 Mercedes-Benz GLB-Class2026 Mercedes-Benz GLC-Class2026 Mercedes-Benz GLE-Class2026 Mercedes-Benz GLS-Class2026 Mercedes-Benz SL-Class2025 Mercedes-Benz AMG GT2025 Mercedes-Benz C-Class2025 Mercedes-Benz CLA-Class2025 Mercedes-Benz CLE2025 Mercedes-Benz E-Class2025 Mercedes-Benz EQB-Class2025 Mercedes-Benz G-Class2025 Mercedes-Benz GLA-Class2025 Mercedes-Benz GLB-Class+ 265 moreAssociated Documents - April 7, 2026•Document ID: 11031202Service Bulletin/Repair InstructionsELECTRICAL SYSTEM; VISIBILITY/WIPER
- Mfr Comm. #:
- LI72.40-P-071889
- Date Added:
- April 8, 2026
- Manufacturer:
- MERCEDES-MAYBACH
SummaryComplaint When closing the door, the side window may remain slightly open (short stroke position). Automatic window raising function of side window inoperative. NOTE: Window is fully operational while holding the switch Cause Software in door control unit (N69/x). Starting the engine at the same time as the door is closing (short stroke closure of window lifter) may result in a denormalization of the window lifter system. Remedy Update the software in the affected door control unit (N69/x). • This requires the door control unit (N69/x) to be commissioned. • (Path: XENTRY Scope; Control units view; DCU-XX (N69/x); Adaptations; Commissioning) Availability of the repair software in the field organization: • Since 10.10.2020 for model series 238, 257, 217 (FACELIFT) and A/C205 (FACELIFT) • Since 12.04.2021 for model series 118
Associated Products (21)2023 Mercedes-Benz C-Class2023 Mercedes-Benz E-Class2022 Mercedes-Benz C-Class2022 Mercedes-Benz E-Class2021 Mercedes-Benz C-Class2021 Mercedes-Benz E-Class2021 Mercedes-Benz S-Class2020 Mercedes-Benz C-Class2020 Mercedes-Benz E-Class2020 Mercedes-Benz S-Class2019 Mercedes-Benz C-Class2019 Mercedes-Benz E-Class2019 Mercedes-Benz S-Class2018 Mercedes-Benz C-Class2018 Mercedes-Benz E-Class2018 Mercedes-Benz S-Class2017 Mercedes-Benz C-Class2017 Mercedes-Benz E-Class2017 Mercedes-Benz S-Class2016 Mercedes-Benz E-Class+ 1 moreAssociated Documents - March 27, 2026•Document ID: 11030302Service Bulletin/Repair InstructionsENGINE
- Mfr Comm. #:
- LI01.30-P-072328
- Date Added:
- March 29, 2026
- Manufacturer:
- MERCEDES-BENZ
SummaryComplaint -Check engine light illuminated. -Engine runs rough. -Poor shifting or jerking when accelerating. -Fault codes stored related to mixture formation, injector quantity adjustment, or misfire. Note: One or more of the above symptoms can occur. It is possible that no fault codes are stored. Cause Leaking valve seat in cylinder head. Remedy -Perform cylinder leakage check as noted in WIS group 01.00. If excessive leakage is found determine if leak is from intake or exhaust valves. -If leakage is found from intake or exhaust valves, remove cylinder head and inspect valve seats. -The complete cylinder head must be replaced if valve seat damage is found. The valve seats can not be reworked. -Engine oil and filter should be changed after the repair. Workshop notes cylinder head repair: 1. The intake rocker arm roller is narrower than the exhaust and they must not be interchanged. Mark the rocker arms so they are reinstalled in their original location. 2. Inspect all parts that are being reused (i.e. camshafts, rocker arms) for signs of wear or damage. See WIS doc AH05.20-P-1000-09SZ for examples of normal and abnormal wear. Replace parts with new if damage or wear is found. 3. Check that all rocker arms are correctly located on the camshaft before installing cylinder head cover. Rotate engine at least 2 times and check that there are no problems with rocker arms. 4. The timing chain tensioner can be reused if it extends fully, has no noticeable problems in prior operation, and no chain drive components were replaced. 5. Care must be taken when removing fuel injectors to prevent damage. See WIS doc AR07.03-P-0004-03MM. 6. Cleanliness must be observed during repair to prevent subsequent complaint or engine damage: • When cleaning engine block surface, ensure oil ports are sealed to prevent debris from entering oil circuit. Refer to SI01.40-P-0010A. • No abrasive materials, sharp-edged tools, or unapproved cleaners should be used on engine block surface. Refer to AR01.00-P-0050-01A. • Any debris from cleaning that has entered the cooling jacket should be removed before assembly of engine. The debris can otherwise cause blockage in the cooling circuit leading to engine overheating. If any of the parts listed below are found damaged or in need of replacement during cylinder head valve‑seat diagnosis or repair, and the vehicle has warranty coverage, they must be claimed on a separate parts‑only line. These items are not covered under the cylinder head warranty extension and cannot be included with the claim. • Camshafts • Camshaft adjustment solenoids • Camshaft positioners • Fuel injectors • Hydraulic valve play compensating elements • Roller rocker arms • Spark plugs • Timing chain • Timing chain guide rails
Associated Products (48)2026 Mercedes-Benz CLA-Class2026 Mercedes-Benz GLA-Class2026 Mercedes-Benz GLB-Class2025 Mercedes-Benz CLA-Class2025 Mercedes-Benz GLA-Class2025 Mercedes-Benz GLB-Class2024 Mercedes-Benz CLA-Class2024 Mercedes-Benz GLA-Class2024 Mercedes-Benz GLB-Class2023 Mercedes-Benz C-Class2023 Mercedes-Benz CLA-Class2023 Mercedes-Benz E-Class2023 Mercedes-Benz GLA-Class2023 Mercedes-Benz GLB-Class2023 Mercedes-Benz GLC-Class2023 Mercedes-Benz GLE-Class2022 Mercedes-Benz A-Class2022 Mercedes-Benz C-Class2022 Mercedes-Benz CLA-Class2022 Mercedes-Benz E-Class+ 28 moreAssociated Documents