2027 Mercedes-Benz C300 TSBs
10 Technical Service Bulletins across 7 categories
Infotainment
4 bulletinsComplaint Clanking noise from the area of the speakers in the doors.
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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. Note: Please refer to this document in the warranty claim and, once diagnosis is completed, select the damage code depending on the component part that is causing the issue. If the noise stops when the door trim is removed, please proceed in accordance with LI72.10P067691. Information: In this case, do not use a damage code for the speakers in the warranty claim!
Complaint Radio station cover art does not refresh when switching stations.
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The UI continues to show the old stations 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. Please update the Head unit software to E505.9
Complaint Traffic sign symbol for "Traffic Sign Assist" is blinking in instrument cluster without obvious cause usually...
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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 recheck function in the same location. NOTE: Updated head unit software for AMG's has NOT been released yet. ETA 12/2026. 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)
Complaint The Apple Music app is no longer available in the head unit apps menu after updating the software of the...
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(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. If the app is not shown available, check via the MercedesBenz App Store directly in the vehicle and download the app. NOTE: Please refer to this LI in the warranty claim in the "Notes" section!
Steering
1 bulletinComplaint Slight creaking noises when steering.
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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.
Brakes
1 bulletinComplaint Repeat workshop visit for vehicle vibration while braking from 60MPH.
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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 be checked for other possible contributors. 1. Prior collision damage. 2. Excessive vehicle sitting times without rotating components. 3. Wheel bearing/hub lateral runout. 4. Wheel mating interface has been overtightened (did not follow WIS torque procedures). 5. Mating interfaces have been excessively modified (painted, gouged, bent, etc...). Remedy Read through the entire attached worksheet prior to performing. After performing, please review the final page and perform work accordingly. NOTE: This document is not preauthorization or otherwise dealing with warranty. This is intended for diagnostic purposes only. If there are any questions on how to proceed OR The work sheet has been performed and the vehicle has returned with the same concern. Please perform the measurements as seen in the worksheet again and open a TIPS case to the Body, Chassis, and Entertainment team.
Software & Calibration
1 bulletinComplaint Issue after OTA Update IC Odometer Reading blank("_ _ _ _") IC Maintanence data unavailable Cause OTA Update...
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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 SchlsselID = "ID is not valid" and Anlernstatus = "IC is initialized", as shown in the attached image (image_2). Please run the XENTRY guided test for the listed DTCs and provide the results.
Engine
1 bulletinComplaint Whining / humming noises (described as foghornlike) from the drivetrain in the rear axle area during cornering.
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(figure 1) On the abovementioned 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 the axle shafts. Remedy For precise noise analysis and localization, use the chassis ear/NVH kit and the following driving procedure: 1. Drive the vehicle in a tight circle with the steering at full lock in both clockwise and counter clockwise directions. Vary engine load during the maneuvers If a foghornlike noise occurs comparable to the reference video, the vehicle exhibits the condition If the noise is present: 1. Add 15 ml of additive (Friction Modifier) into the rear axle differential via the filler plug IMPORTANT NOTE: Do NOT use Friction Modifier in vehicles equipped with an electronically controlled locking differential (Code 467). 2. Tighten the filler plug 3. Drive the vehicle until the rear axle differential reaches operating temperature Note: Proper activation of the additive requires elevated oil temperatures After the test drive to operating temperature, evaluate the noise when the rear axle is cold and when warm. If the noise is no longer present: The issue is resolved and the vehicle can be released. If there is noticeable improvement: The vehicle can be released with the explanation that the noise will gradually disappear over an extended driving distance. If the noise is still present and remains unchanged: Replace the rear axle differential.
HVAC & Climate
1 bulletinComplaint CEL illuminates and/or AC does not blow cold.
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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 cold. a. Follow the following procedure: i. Have the air conditioning system recharged. ii. Clear the fault codes afterward. iii. Let the vehicle stand for 8 hours (OBD reset condition). iv. Check whether the fault is still present. b. Open TIPS case with your findings and answers the following questions, send to the HV/LV inbox. i. When exactly did the MIL appeared (immediately at startup or while driving). ii. What was the ambient temperature, any special driving maneuvers, and whether the vehicle had just come out of a climatecontrolled garage.
Lighting
1 bulletinDear Dealer Partners, The part numbers listed in the chart below should no longer be installed and any existing stock...
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must be returned to your facing PDC. The deadline for all dealer returns is Thursday, October 8th, 2026. After October 8th, we will no longer accept returns of these parts. 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. We will replace all returned parts in accordance with the chart below.