2012 Mercedes-Benz S350

Owner complaints

What owners report most

1. Engine3
2. Fuel/propulsion system2
3. Power train2
4. Vehicle speed control2
5. Unknown or other1

Latest complaints

• Nov 21, 2019NY70,000 mi
  Engine

  Engine has oil leak similar to many 2011-2012 diesel model.

• Nov 28, 2016NV54,500 mi
  Engine · Power train
  I did some research on mercedes 3.0L diesel motors and there seems to be an issue with the seal failing about 50,000 miles causing the motor to leak oil and the seal as well as the oil cooler need to be replaced. It IS such a common problem on the 3.0L diesel engines that when you call any repair…

  I did some research on mercedes 3.0L diesel motors and there seems to be an issue with the seal failing about 50,000 miles causing the motor to leak oil and the seal as well as the oil cooler need to be replaced. It IS such a common problem on the 3.0L diesel engines that when you call any repair shop the first thing they ask IS if the car IS a diesel. Also the seal replacement IS all over the mercedes blogs saying the same issue on the 3.0L diesels. Thought it might be something to look into as it IS an engine seal problem and IS occurring consistently in all the 3.0L diesels in the s class, e class, ML class, g class. All models that mercedes sold the 3.0L engine in the us.

• Nov 16, 2016GA57,000 mi
  Fuel/propulsion system · Vehicle speed control

  "Takata recall" the vehicle slips into a limp mode while driving. This have happened several times. I'm taking it to the mb dealer this weekend. 11/16/2016. 57Kmiles

• Aug 30, 2016MD61,750 mi
  Fuel/propulsion system
  Vehicle entered limp home mode while entering intersection. Dealership said codes did not indicate an issue and could not reproduce problem. Only actions taken was a computer test and road test. After leaving the dealer, the vehicle entered the limp home mode again this time on the highway. Dealer…

  Vehicle entered limp home mode while entering intersection. Dealership said codes did not indicate an issue and could not reproduce problem. Only actions taken was a computer test and road test. After leaving the dealer, the vehicle entered the limp home mode again this time on the highway. Dealer then replaced two sensors at the turbo. After returning the vehicle to me, it entered the limp home mode again, also while driving on the highway. This time, dealer replaced the turbo when it was brought back in for repair. The vehicle still entered the limp home mode after this repair. So the dealer has also replaced the catalytic converter. Problem still persisted and caused a hose to rupture. This was replaced and the problem still persists after a month of troubleshooting and parts replacing.

• Mar 30, 2016CA52,000 mi
  Power train
  While driving at freeway speeds car went into limp mode. Engine rmp were limited to 1500rpm and speed dropped to 25mph.this happened 3 times during week of 3/14/16 and again on 3/22/16. Had to make defensive emergency maneuver to steer the car away from the traffic lanes and stop on the side of the…

  While driving at freeway speeds car went into limp mode. Engine rmp were limited to 1500rpm and speed dropped to 25mph.this happened 3 times during week of 3/14/16 and again on 3/22/16. Had to make defensive emergency maneuver to steer the car away from the traffic lanes and stop on the side of the freeway. Was almost rear ended by a semi. Car had to be turned off and restarted to come back to normal driving mode. Car was taken to mercedes dealer and it was diagnosed to be a bad torque converter causing this limp mode. Dealer repaired the car by replacing the torque converter. There was no check engine light. When the dealer hooked up their computer there were codes for bad torque converter.

• Apr 21, 2015CA50,000 mi
  Engine · Vehicle speed control
  TL* the contact owns a 2012 mercedes benz S350. While driving approximately 65 mph, the vehicle decelerated without warning. the contact then coasted over to the emergency lane and there were no warning lights illuminated. The vehicle restarted; however, the failure recurred multiple times. The…

  TL* the contact owns a 2012 mercedes benz S350. While driving approximately 65 mph, the vehicle decelerated without warning. the contact then coasted over to the emergency lane and there were no warning lights illuminated. The vehicle restarted; however, the failure recurred multiple times. The vehicle was taken to the dealer for diagnostic testing. The technician diagnosed that the side charge air hose into the throttle actuator was torn and caused the loss of hose pressure. Both the left and right hose needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 50,000.

• Apr 3, 2015GA25,000 mi
  Unknown or other

  When I closed the hood, a section of the radiator grill broke. *tr

Service bulletins

Technical service bulletins and other communications the manufacturer sent dealers about this vehicle. Ask a dealer for the full document by its number.

• 11010818Complaint Transmission control unit Y3/8n4 (fully integrated transmission control unit (VGS)) not listed in quick test and/or no communication possible with VGS. Cause Transmission control unit Y3/8n4 Remedy It is important that LI54.15-P-057373 is processed before replacing any component parts (transmission 722.9). After processing and complying with the above documents, perform a reset on the transmission control unit Y3/8n4 (VGS) (ignition reset), check that the transmission connector is seated correctly and inspect the PINs for concerns. If communication with the VGS cannot be established afterwards, the component part 'electrohydraulic controller unit (EHS)' must be replaced, as it is not possible to transfer the valve characteristics under the above-mentioned conditions. Installation of a VGS repair kit is not permitted in this case.
• 11010494Complaint Rear lamps fogged up/not leaktight. Cause Fogging of the rear lamps is a natural phenomenon, which can occur under certain climatic conditions. This does not lead to any technical impairment of the rear lamps. Remedy Rear lamp: Remedy 1: Clearing fogged/condensed rear lamps: 1. Drive the vehicle into the workshop (temperature higher than +18 C/+64.4 F) Note: Do not wash the vehicle or subject it to high-pressure cleaning before the defogging test. 2. Switch off the engine and connect battery support via a charger. 3. Open the trunk. 4. Switch on the exterior lighting. 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 (defogging progress). Note: -If no reduction in the degree of fogging is visible, the rear lamp is defective and must be replaced. -It is not physically possible to defog the headlamps completely some residual fogging may remain. Fogging does not impair the functionality or the service life of the rear lamps. -Simultaneous fogging of multiple component parts indicates extreme climatic conditions and also does not impair the functionality or the service life of the rear lamps. Remedy 2: You can recognize a defective rear lamp as follows: 1. Check the rear lamps to ensure that no external damage is present, and that the differential aeration cells and the diaphragm are present and correctly seated. -> If there are signs of external damage on the rear lamp, the component parts must be replaced as per WIS instructions. 2. Check the electrical connectors of the plugs and pins. -> If moisture/corrosion/etc. is present, the component part must be replaced as per WIS instructions. 3. Check for leak tightness -> Close all openings with Terostat IX or similar and establish and stabilize via an overpressure (4050 mbar) via the plug. -> In the event of a sudden pressure drop, the component part must be replaced as per WIS instructions. Note: External damage to the rear lamps does not constitute a warranty or goodwill case.
• 11009122Complaint Washer fluid system leaks Cause Various possible causes: 1. Washer fluid reservoir itself. 2. Seal on washer fluid pump/washer fluid reservoir. 3. Washer fluid pump. 3.1. Distributor housing leaks. 3.2. Pump fitting leaks. 3.3. Washer fluid hose cannot be snapped into place on pump fitting. 3.4. Washer fluid hose will not stay on pump fitting, although connector OK. 4. Washer fluid line. 4.1 Connector will not stay on pump fitting because it is broken. 4.2 Sealing ring in connector missing. 4.3 Sealing ring in connector fitted, but deformed and therefore leaks. 4.4 Damage to washer line by animal. 5. Seal on heating washer fluid reservoir/washer fluid reservoir. Remedy Replace defective component parts only. Do not replace any adjacent component parts that are intact. Note: Repair kits for washer line hoses do exist to allow patches for line damage.
• 11008873Complaint Tension-releasing impact of the propeller shaft with the force-free in D "KID" function, after vehicle has stopped. Cause The tension-releasing jolt in the drivetrain originates as a result of the "release" of energy stored when braking through the force-free switch after stopping. It is suspected that the longitudinal bearing is being placed under tension here as a result of the vehicle "dropping off". Remedy 1. Mark the installation position of the joint prior to the removal (picture a+b). This is important for vehicles with a weighted drivetrain ex factory to ensure correct installation after operations have been completed. 2. Clean and degrease propeller shaft toothing. The toothing must be free of grease, e.g. through the use of a brake cleaner. Do not use wire brushes, else the surface could be damaged (picture c). 3. Coat propeller shaft toothing with A 000 989 16 08 Antifriction coating. Coat the entirety, ensuring that the subsurface is no longer visible. When doing so, only coat the outer toothing. Ensure that the coat is not too thick, otherwise the coating could chip (picture d). 4. Observe the drying time of at least 1 hour. 5. Lightly grease the propeller shaft toothing at the outer and inner toothing with A 001 989 44 51 12 Grease (picture e).
• 11008323Complaint Headlamps fogged or droplets forming. Cause Due to its outlet openings, the headlamp is an "open system". This means that acidic gases, moisture, dirt and exhaust gases can penetrate into the headlamp. This can lead to the formation of condensation on the lens of the headlamp. The headlamps comply with all applicable US standards and regulations. Remedy Check housing cover of lamp unit for natural fogging or condensation as per LI82.10-P-078301. If a reduction in the degree of fogging is visible, the desiccant packs can be used once the condensation has completely evaporated. Note: Order service covers and desiccant packs based on the validity description. 1. Remove headlamps. 2. Remove all grommets from outlet openings. 3. Seal vent openings with sealing profile. Important: All openings must be sealed carefully for the pressure compensation diaphragm to work properly! 4. Remove existing service cover. 5. Place desiccant packs into the new service covers and bolt down (Picture_01). 6. Glue the new diaphragm onto the intended surface at the service cover (Picture_02). Note: The bonding surface must be clean and dry. 7. Attach service cover with desiccant pack at headlamp. 8. Install headlamp. To ensure that the desiccant pack (absorption) acts effectively, the headlamp has to be air-sealed. Observe or check the following points for this: 1. Seals at the central connector must all be present and correctly fitted (Picture_03). 2. The new transparent diaphragm must be correctly bonded (Picture_04). 3. Check headlamp housing for any external damage.
• 11008091Complaint During a phone call, the called party has difficulty understanding/cannot understand the driver, or interference/background noises are audible to the called party during a call. It becomes increasingly difficult to understand as the speed rises. Cause A. Seating of the microphones in the headliner. Side edges are covered by the textile cover (see picture "1") B. Assembly of microphones (B25/20 or B25/21) in the headliner. C. Dirt inside the microphone housing Remedy 1. Press finger on rear of microphone (on adhesive tape) 2. Remove microphone cap from the front 3. Eliminate protruding material residues of the microphone cutout at the headliner, e.g. with a soldering iron. The microphone must be seated in the headliner as shown in picture "2". 4. Push microphone from behind until it is firmly pressed into the headliner 5. Maintain pressure and press/clip cap into microphone from the front. Note: The cover cap must be clearly heard and felt to engage. 6. This procedure must be carried out on both microphones (B25/20 and B25/21) Note: It is recommended to replace the cover caps. The non-woven cloth in the cover cap protects the microphone from soiling and must not be removed. NOTE: The information contained in this document is intended for use by trained, professional technicians with the knowledge to properly and safely perform diagnosis and repairs on Mercedes-Benz vehicles, using Mercedes-Benz approved tools and equipment. It informs service technicians about conditions that could occur in certain vehicles and provides information that could assist in proper vehicle diagnosis, service, or repair. It does not indicate that a defect is present in any vehicle referenced in this document nor does it imply warranty coverage. DO NOT assume that a symptom or condition, or a described cause of a symptom or condition, affects any particular vehicle or groups of vehicles, or that a described repair applies to any particular vehicle or groups of vehicles. There can be multiple causes resulting in the same or similar symptoms or conditions described in this document, and trained professional service technicians must use their diagnostic skills to make evaluations on a case-by-case basis. The information contained in this document does not guarantee warranty coverage nor does it extend the vehicles warranty in any way.
• 11008064In our continuing efforts to ensure the proper performance and quality of your vehicle, we are writing to inform you that on certain Model Year 2011-2018 C-Class, E-Class, S-Class, G-Class, CL, CLS, ML, GL, GLE, GLS, GLC, SL, and AMG GT vehicles with 6 and 8 cylinder gasoline engines, the software of the engine control unit may not meet current specifications. Under certain conditions, the catalyst heating might not work. Therefore, an Emission Service Campaign is being conducted to remedy the situation. Our records indicate that your vehicle is included in the affected population of vehicles.
• 11007974Complaint Headlamps leaking or fogged Cause The fogging of the headlamp is a natural phenomenon which can occur under certain climatic conditions. In contrast to a leaky headlamp, physical fogging does not result in a technical impairment of the headlamp. A leak test must be performed to determine if physical fogging exists or if the headlamp is leaky. Remedy In advance, observe LI82.10-P-078301 "Headlamps or Front Fog Lamps Leaking or Fogged". 1. Prepare headlamp/check for external damage: For headlamps with a closed system 1. Check the headlamps for any external damage and check also for correct seating of the Gore-diaphragm/correct latching of the cover caps. 2. If the headlamp exhibits any external damage, replace the headlamp. For headlamps with an open system 1. Check the headlamps for any external damage and seal off the vent then make sure the cover caps are latched correctly into place. 2. If the headlamp exhibits any external damage, replace the headlamp. Note: A headlamp with external damage is not a warranty or goodwill case. 2. Leak test of headlamp with overpressure: Connect test adapter to pressure tester. (Figure 1) Check test adapter for leak tightness. To do so, connect plug and coupling (picture 2) and apply a maximum overpressure of 30 mbar. The pressure must remain constant. If the pressure does not remain constant, use a new adapter. Seal all the outlet openings using sealing compound and the given diaphragm with the plunger (picture 3). (Picture 4) Make allowance for the different headlamp variants here (there are different outlet openings). Check if the headlamp needs to be removed to gain access to the diagnostic socket on the headlamp housing. Plug the adapter onto the diagnostic socket on the headlamp housing. (Picture 5). Apply a maximum of 30 mbar overpressure to the headlamp housing. Note: If the maximum overpressure of 50 mbar is exceeded the headlamp seal will be damaged. If a pressure drop of less than 10 mbar is measured within 30 seconds, the headlamp is not leaky and the problem is down to natural physical fogging. If a pressure drop of more than 10 mbar is measured within 30 seconds, the headlamp is leaky. Note: The leaky position can be localized with the aid of soap suds. Replace any leaky headlamps. Note: Desiccant packs can be installed for headlamps that are not leaky. See: LI82.10-P-064766 Fogged headlamp, desiccant pack installed - open ventilation system LI82.10-P-078304 Fogged headlamp, desiccant pack installed - closed ventilation system
• 11007753Complaint Headlamp or 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. Headlamps comply with all applicable standards. 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 and LED rear lamps: 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 or trunk. 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/+64.4F). 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 the formation of condensation, check the headlamp for a defect. (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. Remedy 2 A Damaged 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 in accordance with 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. With headlamps, it is possible to install desiccant packs if the problem occurs repeatedly. Open ventilation system: LI82.10-P-064766. Closed ventilation system LI82.10-P-078304
• 11006658Mercedes-Benz AG ("MBAG"), the manufacturer of Mercedes-Benz vehicles, has determined that on certain Model Year (MY) C-Class, E-Class, S-Class, G-Class, CL, CLS, ML, GL, GLE, GLS, GLC, SL, and AMG GT (204, 205, 207, 212, 213, 217, 221, 222, 463, 216, 218, 166, 292, 253, 231, and 190 platforms) vehicles with 6 and 8 cylinder gasoline engines, the software of the engine control unit may not meet current specifications. Under certain conditions, the catalyst heating might not work. MBUSA will conduct an Emission Service Campaign. An authorized Mercedes-Benz dealer will update the engine control unit software on the affected vehicles. Affected customers will be notified via First Class letter to have the update performed on their vehicle.
• 11005294Complaint Rear lamps fogged up/not leaktight. Cause Fogging of the rear lamps is a natural phenomenon, which can occur under certain climatic conditions. This does not lead to any technical impairment of the rear lamps. Remedy Rear lamp: Remedy 1: Clearing fogged/condensed rear lamps: 1. Drive the vehicle into the workshop (temperature higher than +18 C/+64.4 F) Note: Do not wash the vehicle or subject it to high-pressure cleaning before the defogging test. 2. Switch off the engine and connect battery support via a charger. 3. Open the trunk. 4. Switch on the exterior lighting. 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 (defogging progress).
• 10248178Mercedes-Benz AG ("MBAG"), the manufacturer of Mercedes-Benz vehicles, has determined that on certain Model Year ("MY") 2012 S-Class (221 platforms) vehicles, the injector codes might no longer be stored in the engine control unit software after installation of the Approved Emission Modification (AEM). The cached injector code may have been lost due to a communication error during installation of the AEM. Customers may experience the MIL illumination or in rare cases, increased engine noise or rough running. MBUSA will conduct an Emission Service Campaign in which an authorized Mercedes-Benz dealer will recode the correct injector codes to the engine control unit on the affected vehicles
• 10248173Mercedes-Benz AG ("MBAG"), the manufacturer of Mercedes-Benz vehicles, has determined that on certain Model Year (MY) 2009-2012 GL-Class, ML-Class, R-Class, and S-Class (164/166, 251, 221 platforms) vehicles, the coding for the engine control unit does not correspond to the specifications as part of the BlueTEC update diesel field measure (aka Emission Modification). This could result in the VIN number not being read out from the vehicle. This could affect the vehicle smog check. MBUSA will conduct an Emission Service Campaign in which an authorized Mercedes-Benz dealer will update the SCN coding for the engine control unit on the affected vehicles.
• 10248162Crease formation on genuine leather seat covers in vehicles with low mileage Objects left on the seats for extended periods of time (pressure marks). Objects wedged between the seat backrest and seat cushion (e.g. seat belt buckle). Light initial creases due to vehicle handling. Light creases in the outer covers originating from the production process (missing finish). Heat treatment of the seat covers using heat gun and plastic wedge. Be very careful to not overheat the seat material!
• 10205233Mobile phone cotacts are not transferred completely.
• 10205225Headlamps fogged.
• 10202531Touch pad: Search lighting does not dim or does not turn on.
• 10186141NTG5.5: Incorrect time shown on instrument cluster, COMAND display, and analog clock
• 10181124Harsh engagement when changing gear range from P to D or R
• 10177571Lamp unit fogged or droplets forming. Due to the vent openings, the lamp unit is an "open system". This means that acidic gases, moisture, dirt and exhaust gases can penetrate it. This can result in deposits on the diffuser and lens. Check housing cover of lamp unit for natural fogging or dew as per GI82.10-P-009047. . 1. If a reduction in the degree of fogging is visible, the desiccant packs can be used once the condensation has completely evaporated. 1.1. Order the required service covers by referring to the variant overview. 1.2. Remove lamp unit 1.3. Remove all grommets from vent openings. 1.4. Seal vent openings with sealing profile. Important: All openings must be sealed carefully for the pressure compensation membrane to work properly! 1.5. Remove existing service cover 1.6. Place desiccant packs in new service covers and bolt down 1.7. Stick new diaphragm onto specified surface on service cover [picture of service cover] Note: The bonding surface must be clean and dry. 06
• 10176670To enhance the satisfaction of our customers, avoid further costs of litigation and return focus to its core businesses, Mercedes-Benz USA, LLC (MBUSA) has entered into a settlement regarding claims relating to alleged mold and mildew type odors originating from the HVAC system in certain Mercedes-Benz vehicles. As part of the settlement, MBUSA has agreed to offer sliding-scale warranty coverage for certain vehicles diagnosed as having mold or mildew type odors originating from the HVAC system?although that coverage will not take effect until the settlement is judicially approved and other events occur; likely not until December 7, 2020 at the earliest (see below). If the settlement becomes effective, coverage will include cleaning of the evaporator and replacement of the HVAC filters
• 101766615 to 4 coasting downshift - shift quality concern with cold trans- mission oil on MODEL 217 or 222 in combination with ENGI- NE 278 and TRANSMISSION 722.9 without code 835/498
• 10167572If it is necessary to replace an HV battery, the return will only be accepted with the filled-out ?Analysis Sheet for Transportability of High-Voltage Batteries Form? accompanied by: , the removed part, the quick test printout, the BMS control unit log printout, the repair documentation and with all required documentation listed in Section E of the Form.
• 10167554Engine diagnosis warning lamp activated. Fault code P045600 "Very fine leak" or P044200 "Fine leak" stored in engine control unit.
• 10167539Engine rattling noise after engine start for several seconds
• 10167513The engine diagnosis warning lamp - check engine lamp (CEL) is active. One or more of the faults relating to the throttle valve actuator (M16/6) listed under 'Control unit / Fault' is/are stored in the engine control unit (N3/10).
• 10167498ESP warning message in instrument cluster. One of the fault codes C219700 or 630900 is logged in the ESP control unit (N30/4).
• 10167487Minor leaks at the oil duct of the left or right cylinder head of engines 157, 276 and 278. 1. Left cylinder head: Oil passage plug hole on left beside mechanical vacuum pump. 2. Right cylinder head: Oil passage plug hole below high-pressure pump housing.
• 10167019Blind Spot Assist inoperative.
• 10167006Engine diagnosis warning lamp active. Fault code 20BE1B and/or 20BD1B (The heating element of the AdBlue tank has a malfunction) is logged in the Blue-Tec control unit.
• 10166980Traces of oil in area of oil cooler (inner V) on engine 642
• 10166978Engine diagnosis warning lamp lights up - Fault code entry (FC) 14A600 or 14A700
• 10166976Message in instrument cluster "DISTRONIC PLUSCurrently Unavailable - See Owner's Manual"
• 10166975This Customer 1 Action has been initiated because certain mbrace subscribers were recently contacted by mbrace informing them that they need to have an i-button call performed to ensure their mbrace device has registered with the Verizon Telematics systems. If the i-button call failed or if the customer was unable to perform the i-button call, the mbrace agent instructed the customer to make an appointment with their dealer to have the issue corrected and/or i-button call performed. The vehicles impacted range from model year 2002 to 2014.
• 10166107Seat belt height adjustment nonfunctional
• 10166106Grinding noises can occur in the backrest on active multicontour seats with the backrest under load and the seat ventilation switched on
• 10166102No inflation of one or more air cushions on the massage/multicontour/dynamic seat modules (driver, front passenger and rear) Bubble formation in one or more seats with massage/multicontour/dynamic seat modules (driver, front passenger and rear)
• 10166100Dynamic seat (DS) pneumatic pump / multicontour seat pneumatic pump makes noises.
• 10166099Pneumatic comfort systems with insufficient performance, entirely inoperative or leaky.
• 10166098Multicontour system fails during air release procedure. The system becomes operational again after an ignition change. Fault code 9E8900 is stored.

Every Mercedes-Benz S350 model year

Bars are owner complaints, dots mark years with recalls. Select a year to open its report.