COMMUNICATION: AUTO CRASH NOTIFICATION; ELECTRICAL SYSTEM:SOFTWARE
2020 Mercedes-Benz GLC 350
Recalls, owner-reported complaints, investigations and safety data
Data refreshed
Overview
Our database contains 1 NHTSA owner-reported complaint for the 2020 Mercedes-Benz GLC 350, most frequently naming the body & structure, electrical and engine categories. 2 safety recalls have been issued covering this model year; and 121 manufacturer communications are on file.
Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.
Complaint activity over time
When owners filed reports about this model year
Not enough dated records to plot a meaningful trend — 1 month of data.
What owners report
Complaints grouped by the component NHTSA recorded
- Body & structure133.3%
- Electrical133.3%
- Engine133.3%
Percentages are of component mentions. A single complaint can name more than one component, so these do not sum to the total complaint count.
Safety recalls
2 campaigns cover this model year
Recalls apply to specific vehicles, not to every vehicle of a model year. Check your VIN with NHTSA or your manufacturer's dealer to confirm whether a recall affects your vehicle.
Check a VIN on NHTSA.govCOMMUNICATION: AUTO CRASH NOTIFICATION; ELECTRICAL SYSTEM:SOFTWARE
Recent owner complaints
Reports submitted to NHTSA, shown in the owner's own words
Engine coolant after 2000 miles from topped off by dealership got low and sparked fire, and totaled my car. Warning alert was ON to say turn off engine remove key. Articles related to this: 800,000 Mercedes-Benz Owners Warned Their Cars Could Catch Fire (forbes.com) Daimler warns car owners of fire risk it lacks parts to fix | Reuters 800,000 Mercedes Vehicles Are In Risk Of Catching Fire, But They Don't Have The Parts To Fix It (topspeed.com) Auto manufacturer Daimler advised 800,000 Mercedes-Benz owners that a technical defect could cause their cars to catch fire, but said it lacked the parts to fix the defect immediately, warning owners to instead drive “particularly carefully.” When confronted with the above with Mercedes Benz my vehicle fire MB maintained that the fire is a hot surface ignition issue and denied the car had any design issue. In the article, MB's warning to owners to instead drive "particularly carefully" means to me that they do admit there are critical and chronic issues with the car that would not only produce trip interruptions but catch fire altogether. It is mandatory for Mercedes to redesign the coolant's chronic issues and make the recall so that more owners will not be faced with the problem I had -- total loss of the vehicle.
- NHTSA ID
- 11475568
- Incident
- Mar 8, 2022
Manufacturer communications
A bulletin sent by a manufacturer to its dealers. Not a recall, and repairs are not necessarily free.
SERVICE BRAKES
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 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 pre‑authorization 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.
STRUCTURE:BODY
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. 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 LI72.10‑P‑067691. Information: In this case, do not use a damage code for the speakers in the warranty claim!
STRUCTURE:BODY
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. Information: Please refer to this document in the warranty claim and, after completing diagnosis, select the damage code corresponding to the component part that caused the problem. • If the noise stops when the door trim is removed, please proceed in accordance with LI72.10-P-067691. Information: In this case, do not use a damage code for the speakers in the warranty claim!
POWER TRAIN
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 supply constraint and the planned introduction of ATF 236.18. - Supplement existing communications and address common workshop questions related to maintenance, repairs, and fluid applicability. - Provide technical clarification and practical workshop guidance during the temporary supply constraint period. Dealers should continue to reference the latest News Channel Updates (NCUs) for the most current information regarding availability, ordering processes, supply status, and other related updates. Cause Damage to the Shell production facility has resulted in 236.17 oil supply being reduced to 50% of normal output until the end of 2026. Remedy Please first check Latest NCU updates for latest detailed information. Please continue placing orders through Paragon as normal. Supply is expected to remain reduced and allocation measures are currently in place. We ask for your patience through this restricted supply period. Most orders will be filled in the order in which they were received, as supply is replenished. Those dealers with zero inventory, and pending orders, will receive priority. We expect supply to be stabilized in September 2026. Approved Fluids: Only use transmission fluid from the approved list found on the Mercedes-Benz Operating Fluids website. Non-approved fluid will result in mechanical damage to the transmission and must be avoided. https://operatingfluids.mercedes-benz.com/sheet/236.17 Approved fluids can be claimed as follows if there is no Mercedes-Benz part number: Part # ATFSUB1L - TRANSMISSION FLUID 1 LITER ATFSUB5L - TRANSMISSION FLUID 5 LITER Dealerships with Zero Inventory AND Grounded Vehicles: If a vehicle is currently grounded for repair at your dealer due to no 236.17 inventory, we may be able to expedite your order. Please open a StarSupport ticket including the following information: (Parts Related Inquiry>National Accounts>Zep) • LI document number • Short explanation of repair needed for grounded vehicle • Current days down of RO Maintenance and Service Interval Guidance Published maintenance intervals remain unchanged. Vehicles should continue to be maintained in accordance with the applicable maintenance schedule. This LI does not revise or extend any published maintenance interval requirements. If all required parts and materials are not available prior to scheduling or beginning a transmission service, dealers should consider postponing routine preventative transmission maintenance until the necessary parts become available. For vehicles that have not yet reached the applicable maintenance interval and do not exhibit transmission-related concerns, there is no need to recommend preventative transmission services prior to the scheduled maintenance interval. When evaluating whether routine transmission maintenance can be deferred until parts become available, dealers should consider: • Overall vehicle condition • Vehicle usage and operating conditions • Presence of transmission-related symptoms or customer complaints • Customer expectations and vehicle operating requirements • Availability of required parts and materials Introduction of New Fluid Specification 236.18 Mercedes-Benz is currently preparing the introduction of ATF 236.18 as an additional approved transmission fluid solution for applicable NAG3 transmissions. At the time of publication of this LI, ATF 236.18 is not yet available for dealer ordering or workshop use in the U.S. market. See attachment for further details.
ELECTRICAL SYSTEM
• Always use the latest XENTRY Diagnosis software release with all available add-ons. • Make sure to follow the operation steps exactly as described in XENTRY Diagnosis! • Use a battery charger to ensure sufficient power supply of the vehicle on-board electrical system battery (greater than 12.5 V). • If XENTRY Diagnosis is already connected to the vehicle, start with operation step 2. If two or more software updates or SCN coding’s are performed during one workshop visit or SCN coding operations are performed, operation items 02-4762 and 02-5058 must only be invoiced once for each workshop order! Work Procedure: 1. Connect XENTRY Diagnosis. 2. Update engine electronics (ME) control unit software. To do so, select menu item "Quick test view → N3/10 - Engine electronics 'MED40' for combustion engine 'M274' (ME) → Adaptations → Control unit update → Update of control unit software". Then follow the user guidance in XENTRY Diagnosis. 3. Disconnect XENTRY Diagnosis.
POWER TRAIN
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 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).
Manufacturers file copies of the bulletins they send to dealers with NHTSA. These often describe diagnostic or repair procedures for a known condition. They are not recalls: repairs described in a bulletin are usually only free if the vehicle is still under warranty or the manufacturer has extended coverage.
Compare model years
Complaint and recall counts across every year of this model
Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers. Older model years have had longer for reports to accumulate.