2023 Mercedes-Benz C300 Technical Service Bulletins

359 technical service bulletins (TSBs) are on record for the 2023 Mercedes-Benz C300. 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.

• 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…
• 11032704May 15, 2026Seats. Complaint One or more seat functions are restricted or inoperative. This may include: • Seat memory • Automatic seat adjustment • Easy Entry/Exit • Head restraint presetting • Collision avoidance with bench seat at rear • Actuation by other vehicle systems Seat normalization is missing, and fault code B228678 – “The control unit calibration has been lost or was not performed. Adaptation or adjustment is not…
• 11032699May 12, 2026Back-over prevention (rear camera), Electrical system, Lane departure. 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.
• 11032599May 12, 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.
• 11032576May 8, 2026Steering. 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 If noise only occurs when adjusting the steering column via electric actuation please perform: 1. Disassemble bellows of steering column tube module. 2. Move steering column entirely out and entirely down. 3.
• 11032051May 4, 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…
• 11031558Apr 24, 2026Other or unknown. Complaint The intent of this document is to provide workshops with helpful technical reference language. • Commonly used acronyms in LI's and TIPS cases. • Control unit names, numbers, and how to identify. • Network/wiring architecture groups to baumuster quick reference. • Platform to baumuster quick reference.
• 11031367Apr 17, 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.
• 11031580Apr 16, 2026Exterior lighting. Complaint 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.
• 11031272Apr 13, 2026Visibility (wipers, defrost, mirrors). Complaint No heating output is available during electric driving operation. In conventional (combustion engine) driving operation, full heating output is available. Cause Possible defect in the N33/5 water heater (high-voltage PTC booster heater) Remedy If the N33/5 water heater (PTC booster heater, high voltage) is defective, it must be replaced with the latest part number. Note: Please refer to the information in…
• 11031201Apr 8, 2026Air bags. Complaint SRS indicator light illuminated in the instrument cluster. Electrical fault in the rear airbag/window airbag that may cause a connection between the airbag pins or to the vehicle mass Cause Contact problems that create a short circuit between the pins or to the vehicle ground Remedy Connect and disconnect the affected airbag five times Then the squib must be carefully blown out with dry compressed air…
• 11031198Apr 8, 2026Exterior lighting. Complaint Optical irregularity in the light guide of the ambient lighting. Cause Exposure to external factors, e.g. cleaning or disinfecting agents, creams, mechanical stress, or impacts. Remedy The assessment of the complaint must be carried out from the normal seat position. Turn on ambient lighting and set to maximum brightness. The vehicle must be inside the workshop; the interior must not be exposed to any…
• 11031256Apr 2, 2026Body and structure, Electrical system. 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…
• 11031255Apr 2, 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…
• 11031218Apr 2, 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…
• 11030316Mar 30, 2026Visibility (wipers, defrost, mirrors), Electrical system. Complaint No heating output is available during electric driving operation. In conventional (combustion engine) driving operation, full heating output is available. Cause Possible defect in the N33/5 water heater (high-voltage PTC booster heater) Remedy If the N33/5 water heater (PTC booster heater, high voltage) is defective, it must be replaced with the latest part number. Note: Please refer to the information in…
• 11030302Mar 27, 2026Engine. Complaint -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…
• 11030295Mar 26, 2026Body and structure, Electrical system. Complaint The "easy entry and exit feature" function deactivates itself after a brief period. (see attachment) Cause The cause is currently being investigated. Remedy Update the HU7 to the latest software version, then perform a factory reset of the HU7.
• 11030301Mar 25, 2026Other or unknown. Complaint The intent of this document is to provide workshops with helpful technical reference language. • Commonly used acronyms in LI's and TIPS cases. • Control unit names, numbers, and how to identify. • Network/wiring architecture groups to baumuster quick reference. • Platform to baumuster quick reference.
• 11030299Mar 25, 2026Electrical system. Complaint Customer concern for ESP/Brake or Steering yellow instrument cluster message AND C220564 in the N80 Steering Column Control Module (Valeo Parts only). To check which supplier steering column module is present in the vehicle, see attachment "Supplier Identification". Cause Triggered due to communication related software timing. Remedy New software A2239026336. Update N80 (Steering Column Module) to at…
• 11030290Mar 25, 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 Root cause currently being investigated. Remedy Please do not replace any parts. Please create a TIPS case to Body/Chassis/Entertainment inbox.
• 11030159Mar 19, 2026Electrical system. Complaint Mercedes me connect services inoperative (me-Call, Remote Status, etc.). Mercedes me services - activation not possible Notes: - The event code "B16AC00 - The configuration of the SIM card is erroneous" is active and stored - The head unit shows no internet connection Cause The RAMSES module may be faulty. This fault profile can be recognized as follows: With XENTRY Diagnosis, enter the "ACTUAL values"…
• 11030089Mar 11, 2026Electrical system. Complaint The vehicle's position on the map is displayed far away from its actual position, e.g. the vehicle is displayed as being in the middle of the ocean. Note: No relevant DTC is displayed during the quick test. Cause The GNSS antenna is not correctly inserted at the GNSS connection (see picture in the attachment) in the head unit (A26/17). Remedy Insert the plug into the GNSS connection and ensure that the…
• 11030088Mar 9, 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.
• 11029961Mar 9, 2026Electrical system, Seats. Complaint The seat may no longer be adjustable using the electric seat adjustment switch on the door module. No related error is stored in the quick test. Cause Under certain conditions, the electric seat adjustment switch may remain in sleep mode. It is then not possible to adjust the seat using this switch. This is a software error. Remedy To restore functionality, perform the following steps: 1. Remove the door…
• 11029959Mar 9, 2026Exterior lighting. Complaint 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.
• 11029916Mar 9, 2026Engine. Complaint Engine vibrations perceived at low rpm. Fault codes for the camshaft position of the intake camshaft (P001100, P001104, P001200) or exhaust camshaft (P001400, P001404, P001500) may be stored. Cause Continuously fluctuating oil pressure in the central valve may lead to damage to the filter screen on the central valve. This can result in damage to the filter screen or the filter screen breaking loose. The…
• 11029927Mar 4, 2026Electrical system. Complaint Yellow information message in driver display (instrument cluster): "Switch on motor to charge the 12V battery" Cause The state of charge (SOC) of the 12V battery has dropped to 45% or less. Remedy This warning message appears as soon as the state of charge (SOC) of the 12V primary battery drops below 45%. This message is displayed to safeguard the vehicle's starting ability.
• 11029919Mar 2, 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 If noise only occurs when adjusting the steering column via electric actuation please perform…
• 11029094Feb 28, 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. Cause There are two identified reasons for this concern: 1. Country code information…
• 11029093Feb 28, 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.
• 11029091Feb 28, 2026Steering. Complaint Stored DTC C220564 - "There is an internal fault in the steering angle sensor. There is an implausible signal." In the quick test, there are also no other DTC's in other control units that point to or reference N80 Steering Column Control Module ("SCCM"). There is no effect on any other components or vehicle functions and it does not cause an instrument cluster light. Cause The DTC only ever occurs during…
• 11029056Feb 28, 2026Air bags, Electrical system. Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain subject vehicles, the SRS control unit software does not correspond to current production specifications. The SRS control unit will be updated to improve vehicle charging functionality during future over-the-air updates. MBUSA will conduct a service campaign. An authorized Mercedes-Benz dealer will update the SRS control…
• 11029083Feb 25, 2026Body and structure, Electrical system. Complaint Tailgate opens unintentionally. Cause Accidental or unnoticed activation of the button to open the tailgate on the vehicle key. E.g. 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…
• 11029025Feb 24, 2026Exterior lighting. Complaint 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.
• 11029134Feb 20, 2026Electrical system, Engine. Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has decided that on certain model year 2023 C-Class, G-Class and SL vehicles, the engine control unit software may not meet current specifications. Our records indicate that your vehicle is included in the affected population. What is the issue?
• 11028907Feb 19, 2026Electrical system. Complaint The check engine light illuminates or the 48 V message is displayed in the instrument cluster Cause Fault code "P0A7F00" stored in the 48 V battery G1/3 and/or is current. Remedy 1. Check the SOHc of A66 48V battery. (For SOHr, see LI54.10-P-080199) 2.
• 11028807Feb 14, 2026Engine, Electrical system. Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain subject vehicles, the engine control unit software does not correspond to current production specifications. As a consequence, the functionality of the post-catalyst oxygen sensor may be impaired due to increased thermal loading. MBUSA will conduct a service campaign. An authorized Mercedes-Benz dealer will update the…
• 11028834Feb 13, 2026Electrical system, Transmission and drivetrain. Complaint Check engine light on with the following fault is current in the VGS Control Unit: P084300 Oil pressure sensor 'A' has a short circuit to positive stored in VGS control unit. Cause Electrical failure of oil pressure sensor integrated into VGS Control Unit Remedy Intelligent Predictive Repair (IPR) recognizes this fault pattern and will provide the necessary repair suggestion. 1. Perform IPR and follow the…
• 11028827Feb 13, 2026Engine. Complaint Engine vibrations perceived at low rpm. Fault codes for the camshaft position of the intake camshaft (P001100, P001104, P001200) or exhaust camshaft (P001400, P001404, P001500) may be stored. Cause Continuously fluctuating oil pressure in the central valve may lead to damage to the filter screen on the central valve. This can result in damage to the filter screen or the filter screen breaking loose. The…
• 11028816Feb 13, 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.
• 11028809Feb 13, 2026Other or unknown. Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain subject vehicles, the TIREFIT sealant bottle may not meet specifications. The possibility exists that the sealant bottle may leak or may have otherwise been removed from the vehicle. MBUSA will conduct a service campaign. An authorized Mercedes-Benz dealer will replace the TIREFIT bottle in the trunk.
• 11028813Feb 12, 2026Transmission and drivetrain. Complaint The vehicle cannot disengage “P” (Park), and a red warning message appears in the instrument cluster. Cause Only vehicles with transmission NAG3C 725.0 and engine M264 with transmission software version 19A/B are affected. (see attachments for how to verify software level) Excessive pressure in the disengaging clutch during monitoring of the parking lock (see attachments for diagram).
• 11028648Feb 7, 2026Electrical system, Engine. Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain subject vehicles, the engine control software might not meet current specifications. As a result, the diagnosis routine for monitoring the air-fuel ratio might not be activated as intended and a malfunction in the oxygen sensor could be erroneously detected causing the “check engine” Malfunction Indicator Lamp (‘MIL’) to…
• 11028640Feb 6, 2026Electrical system. Complaint Activating Navigation Please Wait" message seen on central display. Cause Under Analysis Remedy 1.Reset the MBUX language (e.g., if the MBUX language is set to English, please change it to any other language and then set it back to English again) 2.If the issue still persists after the step 1, Perform a user data reset of the Head Unit. If the above 2 steps still don't repair the issue, please open a TIPS…
• 11028270Feb 3, 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.
• 11028267Feb 2, 2026Engine. Complaint -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…
• 11027899Jan 31, 2026Electrical system. Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain subject vehicles, the ME-SFI control unit software does not meet current production specifications. As a result, a check engine malfunction indicator lamp might erroneously be triggered. MBUSA will conduct a service campaign. An authorized Mercedes-Benz dealer will update the ME-SFI control unit software.

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