2023 Mercedes-Benz GLC 300 Technical Service Bulletins

339 technical service bulletins (TSBs) are on record for the 2023 Mercedes-Benz GLC 300. TSBs are notes manufacturers send to dealers about repair procedures for issues seen in the field. They are not recalls and do not by themselves mean a vehicle has a fault.

• 11038682Oct 26, 2026Body and structure. Complaint Wheezing noises/squeaking noises from the front shock absorbers when passing over surface undulations and rough road. Noise MUST match those heard in the attached videos. Cause • Wheezing noises: Flow noises of the damper oil • Squeaking noises: From the mechanical rubber valve in the dividing piston Remedy In case of complaints, the front shock absorbers must be replaced.
• 11038188Sep 26, 2026Steering. Complaint Slight creaking noises when steering. Cause Noises may come from one or more sleeves of the horn contact plate. Remedy Remove the horn contact plate and check the sleeves for noise; see attached video. If necessary, apply lubricant to the sleeves.
• 11038187Sep 26, 2026Transmission and drivetrain. 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.
• 11038222Sep 25, 2026Electrical system. A software update will be performed that provides enhancements to the robustness and system stability of the communication module. The update is free of charge and runs in the background, which takes about 8 minutes to install. During this time, the vehicle can be driven without any restrictions, and the new software will be active with the next ignition cycle. Remedy MBUSA will conduct an OTA service campaign.
• 11037484Sep 25, 2026Visibility (wipers, defrost, mirrors). Complaint CEL illuminates and/or AC does not blow cold. Cause Potentially relevance to hardware and/or software Remedy Scenario 1: 1. If the AC does not blow cold air, replace compressor (if compressor's index and part number Figure 1 match against Table 1). a. If the compressor does not fall within Table 1, please open a TIPS case. b. Flush procedure must be followed as per WIS. Scenario 2: 1. If AC does blow…
• 11038186Sep 22, 2026Brakes. Complaint Repeat workshop visit for vehicle vibration while braking from 60MPH. NOTE: Although the symptom is similar to a tire or wheel vibration, it is usually readily noticeable that it is distinctly different if it happens at all times or only while braking. Cause Although the cause of the vibration is most likely due to excessive lateral runout on the rotor or hub/wheel bearing, the system as a whole needs to…
• 11038175Sep 17, 2026Electrical system. Complaint Issue after OTA Update IC Odometer Reading blank("_ _ _ _") IC Maintanence data unavailable Cause OTA Update E61.0 Remedy In the IC Control Unit Log, please check the following information: Verify whether DTCs B228229, B228287, and B226656 are present in either A or A+S. Verify that Status Schlüssel‑ID = "ID is not valid" and Anlernstatus = "IC is initialized", as shown in the attached image (image_2)…
• 11038174Sep 15, 2026Electrical system. 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…
• 11038217Sep 14, 2026Body and structure. 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.
• 11037987Sep 14, 2026Transmission and drivetrain. 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.
• 11037834Sep 14, 2026Transmission and drivetrain. Complaint Whining / humming noises (described as foghorn‑like) from the drivetrain in the rear axle area during cornering. (figure 1) On the above‑mentioned vehicles with a mileage up to 15,000 km (about 9,300 mi), noises can occur from the rear axle differential. Cause Drivetrain resonance caused by the gear mesh of the ring and pinion in the rear axle differential in combination with installed damper elements on…
• 11037806Sep 11, 2026Electrical system. 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…
• 11037616Sep 4, 2026Transmission and drivetrain. 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.
• 11037489Sep 4, 2026Electrical system. Complaint The Apple Music app is no longer available in the head unit apps menu after updating the software of the (A26/17 ‑ MBUX multimedia system + instrument cluster (head unit)) to E333.8 / A236 904 19 00. Cause Head unit software (CIVIC206) Remedy NOTE: Do not replace any component parts The new Apple Music app version is now available. The app should automatically be downloaded and available.
• 11037243Sep 1, 2026Visibility (wipers, defrost, mirrors). Cause Internal failure of the scroll wheel within the AC compressor. Remedy Check the compressor's index and part number Figure 1 against Table 1. If listed please perform the following: 1. Replace the compressor, drier, and expansion valve using the applicable WIS instructions. 2. Flush the system using the applicable WIS instructions.
• 11037228Aug 28, 2026Steering. 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…
• 11036527Aug 26, 2026Back-over prevention (rear camera). Complaint Frequent rear view camera flap actuations and/or noise associated. NOTE: Rear view camera functions are NOT affected and still perform in accordance with regulatory requirements. Cause Calibration of the reversing camera is in progress. This is not a malfunction, but an intended system behavior. Remedy An optimization has been implemented to reduce the quantity of rearview camera flap actuations for…
• 11036511Aug 24, 2026Electrical system, Body and structure. 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…
• 11036608Aug 22, 2026Electrical system. 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…
• 11036999Aug 15, 2026Fuel system. Dear Mercedes-Benz Owner: In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA is extending the warranty coverage for the Diagnostic Module for Tank Leakage Detection ("DMTL") on your vehicle from the original New Vehicle Limited Warranty of 4 years / 50,000 miles to 15 years/150,000 miles (whichever occurs first)…
• 11036237Aug 14, 2026Electrical system. Complaint The following most common complaints may be observed: • Brief connectivity interruptions when using Apple CarPlay over Wi-Fi • Audio cuts out • Device not recognized • No operation possible Cause There are multiple possible causes for an iPhone disconnecting from a vehicle’s head unit while using Apple CarPlay.
• 11036142Aug 12, 2026Electrical system. 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.
• 11036101Aug 6, 2026Body and structure. 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.
• 11036077Aug 5, 2026Transmission and drivetrain. 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…
• 11036091Aug 4, 2026Electrical system. Complaint DAB, FM, or SDARS radio reception is limited, only a few stations are found. Cause The firmware installation was incomplete. Remedy In the A26/17 control unit "MBUX multimedia system" (head unit), use XENTRY to carry out the special process "All Modules"; this will reinstall the firmware completely.
• 11035780Aug 4, 2026Transmission and drivetrain, Other or unknown. 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…
• 11035490Jul 31, 2026Fuel system. This NCU replaces the prior NCU issued on May 15, 2025, and contains additional MY 2023 and MY 2024 vehicles which are highlighted below.
• 11035230Jul 17, 2026Electrical system. Complaint After an "Over the Air" update (OTA), FM or SDARS radio reception is limited; only a few stations are found. Cause The firmware installation was incomplete. Remedy In the A26/17 control unit "MBUX multimedia system" (head unit), use XENTRY to carry out the special process "All Modules"; this will reinstall the firmware completely.
• 11035005Jul 14, 2026Transmission and drivetrain. 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…
• 11035016Jul 9, 2026Electrical system. 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…
• 11035003Jul 8, 2026Suspension. 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.
• 11034888Jul 8, 2026Electrical system. 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…
• 11034932Jul 7, 2026Suspension. 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.
• 11034273Jul 2, 2026Electrical system. We are experiencing intermittent issues when flashing A26/17 - MBUX multimedia system + Instrument cluster (Head unit) when using flashing method ethernet to USB-C. Until further notice, please flash via VCI only.
• 11034538Jul 1, 2026Electrical system. 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.
• 11034536Jul 1, 2026Body and structure, Electrical system. Complaint General information on the operation of the PRE-SAFE® Impulse system: The PRE-SAFE® Side Impulse system is a preventive, i.e. pre-collision occupant protection system. The task of the system is to provide additional protection to vehicle occupants when there is a risk of a side impact. It is not a restraint system component in the conventional sense and does not contain an detonator. A potential…
• 11034064Jun 19, 2026Engine, Visibility (wipers, defrost, mirrors). 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 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…
• 11033935Jun 12, 2026Electrical system. Complaint The remaining time shown on the instrument cluster in the workshop menu (days to next due service) is implausible (>365 days) for the following conditions: • for the date of the vehicle handover • or the last conducted and confirmed Service A/B Cause Case 1: Observe the following on vehicles with a disconnected on-board electrical system battery (12V/48V): • The period in which the on-board electrical…
• 11033855Jun 12, 2026Electrical system. 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.
• 11033852Jun 12, 2026Electrical system. 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.
• 11033168Jun 1, 2026Steering. Complaint Rattling/knocking noise from the rear axle steering is audible when driving on rough terrain or cobblestones. Large play in the rear axle steering. Cause Diverse functional play in the rear axle steering. Remedy 1. Detach underfloor paneling under rear axle steering. 2. Unscrew both holders of the rear muffler on the exhaust system and lower the rear muffler 3. Remove heat shield. 4. Remove large clamps…
• 11033164May 29, 2026Electrical system. 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.
• 11033185May 26, 2026Electrical system. 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.
• 11033016May 26, 2026Electrical system. Complaint 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…
• 11033050May 22, 2026Body and structure, Transmission and drivetrain. 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…
• 11033019May 22, 2026Steering. Complaint Noises from the area of the steering column. - Creaking - Squeaking - Chattering - Humming - Grinding Cause At present, there are no known noise problems with the steering column. Remedy Check surrounding area of the steering column for possible noises. • Instrument panel support • Steering column switch module NOTE: Occasionally to verify complaint, the steering column/vehicle needs to be in direct…
• 11032890May 20, 2026Electrical system. Complaint 48V battery (A66) part numbers A 000 982 78 24, A 000 982 57 30, A 000 982 88 31, A 000 982 50 32, A 000 982 87 32) may trigger a fault message ("48 V Service Required" with fault codes P0ADA91, P0ADE91, P0AA100, P0ADD00 or P0AA000) in the instrument cluster. This fault message may prevent the 48 V battery contactors from opening automatically if the 12 V power supply is interrupted. In this case, the 48…
• 11032878May 19, 2026Seats. Complaint Play/noise at height adjuster or in seat guide rail on front seats Cause Tolerances and variations in the manufacturing process Remedy 1. Inspect Seat Height Adjuster Barcode Label (See Pic.1) • Locate the barcode label on the cross tube of the seat height adjuster. • In isolated cases, the barcode label may be located on the front side of the cross tube. If not visible, remove the seat cushion to access…
• 11032875May 19, 2026Visibility (wipers, defrost, mirrors). Complaint 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)…
• 11032736May 15, 2026Suspension, Transmission and drivetrain. 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…

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