2018 Mercedes-Benz GLC 300

From 2000 through 2017, Takata produced millions of air bag inflators using two types of phase-stabilized ammonium nitrate ("PSAN") propellant -- propellant 2004 and propellant 2004L. After prolonged exposure to high temperature cycles and humidity, inflators using propellant 2004 can degrade, causing the propellant to burn too quickly when ignited. The rapid burning can cause the inflator to rupture during deployment, potentially causing serious or even fatal injury to vehicle occupants. See 2016 Blomquist Report at www.nhtsa.gov/sites/nhtsa.gov/files/documents/expert_report-hrblomquist.pdf.Consequently, all frontal inflators using propellant 2004 that do not contain a "desiccant" (a substance that traps and holds moisture) in US vehicles are under recall. These "non-desiccated" inflators either have been or are required to be replaced.In some cases, the remedy part for these recalled inflators was, or will be, an inflator using either propellant 2004 or 2004L that does contain a desiccant. None of these "desiccated" remedy parts (which were installed in older model year vehicles) are currently under recall for a degradation concern. Certain subsets of desiccated PSAN inflators using propellant 2004 for use as original equipment, however, have been recalled for a degradation concern. All Takata inflators produced with propellant 2004L contain desiccant, and none of these desiccated inflators using propellant 2004L are under recall for a degradation concern. There have been no reported field ruptures in any non-recalled desiccated PSAN inflators.It is understood that desiccants fully saturate at some threshold, at which point any additional moisture will not be captured. This means the degradation process observed in non-desiccated inflators using propellant 2004 may also occur in non-recalled desiccated inflators using propellant 2004, assuming additional moisture enters the inflator and high temperature cycling occurs. Based on available information, desiccant saturation can occur within the first five years in the worst environments, and the time required for full saturation is affected by multiple factors. While no present safety risk has been identified, further work is needed to evaluate the future risk of non-recalled desiccated inflators using propellant 2004.Three entities -- Takata (now known as TK Global), the Independent Testing Coalition, and Exponent -- have been studying the long-term behavior of Takata desiccated PSAN inflators using propellant 2004L (as well as 2004) in the presence of moisture and temperature cycling. The research efforts, which include development of predictive modeling techniques and field sample analysis, are ongoing. To date, none of the researchers have identified field evidence showing that propellant 2004L is undergoing a degradation process that leads to aggressive deployment and potential rupture. However, the time in service of such inflators remains short compared to that of the inflators using propellant 2004. Further study is needed to assess the long-term safety of desiccated inflators using propellant 2004L.The Office of Defects Investigation is opening this investigation to examine whether a safety defect related to propellant degradation exists in non-recalled desiccated PSAN frontal inflators manufactured by Takata. This investigation will require extensive information on Takata production processes and surveys of inflators in the field. Lists of recall actions that may have used desiccated PSAN inflators as remedy parts, as well as the makes and models originally manufactured with them, is available with the downloadable version of this document (see nhtsa.gov/recalls?nhtsaId=EA21002 -- note this information is subject to change/revision as the investigation proceeds). This investigation does not supersede EA15-001, which remains open.

On January 8, 2021, after ongoing review with Mercedes Benz, the National Highway Traffic Safety Administration (NHTSA) Office of Defects Investigation (ODI) opened PE21-001 to assess allegations of front roof panel detachments while driving at highway speeds in certain 2015 Mercedes-Benz (Mercedes) C-Class vehicles.The subject front roof panel is a stationary panel composed of polycarbonate and is attached to the vehicle via adhesive at the time of manufacture. The panel is found on subject vehicles equipped with panoramic sunroofs. Over time, the subject panels may exhibit cosmetic degradation leading to replacement of the panel, a procedure which entails: removal of the old panel and adhesive, site preparation, and installation of a replacement panel with new adhesive.The consumer complaints that prompted the opening of PE21-001 all described detachments of front roof panels that had been replaced after the vehicle was put into service.Mercedes' internal investigation identified a broader scope of affected vehicles (2014-2020 CLA, GLA, C, S, GLC, and GLE class) and found the following potential service procedure- related causes of front roof panel detachments:- Improper surface pretreatments such as the use of the wrong primer or cleaner or scoring of the surface; or - Use of the incorrect adhesive.These conditions lead to a front roof panel bond that, even if sound at the time of repair, cannot maintain its strength over time and environmental exposure.Mercedes updated its service and parts ordering systems to reinforce the proper use of specified kits and procedures via webinars, shop foreman meetings, and explicit reference to the risks incurred by diverging from the repair procedures. Mercedes is also furnishing parts ordering assistance, and will hold dealerships accountable for improper repairs.ODI's analysis of the ten complaints it has received from the public (VOQ's) and MBUSA's complaint data submitted in response to the information request letter for PE21-001 identified a total of 57 non-duplicative reports alleging incidents in which the front roof panel detached from the vehicle while in motion. Included within the 57 reports are incidents where consumers state the panel detached ...and flew off into traffic.On March 19, 2021, Mercedes notified NHTSA that it would recall subject vehicles with front roof panels known to have been replaced after the original sale of the vehicle. In total, the recall (designated as Recall 21V197) covers 15,099 vehicles that were ever registered in the United States. Based on Recall 21V197 and the remedy implemented by Mercedes, further investigation does not appear to be warranted at this time.Accordingly, this investigation is closed.The ODI complaints cited above can be viewed at www.nhtsa.gov under the following ODI identification numbers: 11376425, 11352686, 11351629, 11349158, 11341541, 11337594, 11324100, 11311591, 11222127, 11404183

Error code P052E71 on a 2018 Mercedes-Benz GLC 300 4MATIC means the Positive Crankcase Ventilation (PCV) Regulator Valve Performance has a malfunction, specifically that the partial-load ventilation valve actuator is blocked. By research, i found that this is a very common problem on those engines, and no recalls from the company to fix their fault.

NHTSA ID

11753763

Incident

May 12, 2026

Component Failure: The vehicle is equipped with the M274 2.0L turbocharged engine, which suffered a major internal mechanical defect. An authorized Mercedes-Benz dealership diagnosed the vehicle at 79,504 miles with a malfunction in the crankcase ventilation system alongside severe internal defects, quoting a total repair estimate of $9,851 to perform extensive engine work. Safety Risk: This known manufacturing defect involves premature failure and cracking of the pistons, which poses an immediate safety hazard due to potential catastrophic engine failure and sudden, complete loss of motor power while driving at highway speeds. The manufacturer has failed to offer an extended warranty or recall for this known issue on the 2018 model year.

NHTSA ID

11741952

Incident

Jun 21, 2023

Safety Issue: Infotainment display screen produces scrambled pixels during Apple CarPlay navigation while driving. Description: When Apple CarPlay is connected and navigation is in use, the vehicle's infotainment display screen suddenly produces scrambled pixels, rendering the map and display unreadable. This malfunction occurs without warning while the vehicle is in motion, creating a dangerous visual distraction for the driver and uncertainty of where and when to turn or exit. This is a known, recurring issue. On January 7, 2021, I brought this problem to Mercedes-Benz of Indianapolis (Repair Order #624027), where a firmware update was applied and the issue was allegedly resolved. The fix has not proven permanent — the problem has since recurred and continues to present a safety hazard while driving. Despite this being a widely documented issue affecting numerous Mercedes owners, Mercedes-Benz has not issued a recall or technical service bulletin that I am aware of. My dealer is requiring a diagnostic fee of over $250 to inspect the vehicle, and Mercedes-Benz USA customer service has been unreachable. Requested Action: I am requesting that NHTSA investigate this issue and consider whether a Technical Service Bulletin or recall is warranted given the safety implications of a sudden display malfunction while driving.

NHTSA ID

11732752

Incident

Jan 1, 2026

While driving on interstate 4 in Florida with our grandchildren going approximately 70 mph the sunroof on our 2018 Mercedes GLC just exploded no object came into the vehicle and while glass came into the vehiclenot all the glass that made up the sunroof came into vehicle suggesting a pressure issue as apparently blew out

NHTSA ID

11723228

Incident

Mar 5, 2026

The contact's friend owns a 2018 Mercedes-Benz GLC 300. The contact stated that while the owner was driving at an undisclosed speed, the accelerator pedal was depressed, but the vehicle failed to accelerate as intended, and the gear shifter independently shifted to neutral(N). No warning lights were illuminated. In addition, the contact stated that the failure was persistent. The contact stated that the owner forced the gear shifter out of neutral(N). The vehicle was taken to the dealer, where it was diagnosed that the transmission control unit had failed and needed to be replaced. The vehicle was not repaired. The contact related the failure to an unknown recall, but the VIN was not included in a recall. The manufacturer was made aware of the failure, and a case was filed. The contact was advised to contact the NHTSA Hotline to report the failure. The failure mileage was unknown.

NHTSA ID

11708077

Incident

Dec 24, 2025

The contact owns a 2018 Mercedes-Benz GLC300. The contact stated that while driving at various speeds, the vehicle shifted into gear initially without warning. The contact stated that while stopped at a light, the vehicle shut off with the "Transmission Malfunction Stop" message displayed on the instrument panel. The contact was unable to move the vehicle, and the vehicle was towed to an independent mechanic. The mechanic ran a diagnostic test on the vehicle and initially stated that the front drive wheel sensor was defective; however, the contact was then informed that there were no issues with the sensor. Neither the dealer nor the manufacturer was notified of the failure. The vehicle was not repaired. The failure mileage was approximately 90,000.

NHTSA ID

11702561

Incident

Aug 1, 2025

Mileage

90,000 mi

I have P052E71 error code. It’s a crankcase ventilation malfunction. Seems to be a common issue reported widely online on various forums. Mercedes should place a recall on this. The car has 55k miles on it.

NHTSA ID

11699931

Incident

Nov 16, 2025

The contact owns a 2018 Mercedes-Benz GLC300. The contact stated that while operating the vehicle, the message "Front Air Bag Malfunction" was displayed, and the horn became inoperable. The vehicle was taken to the local dealer who diagnosed that the steering column and air bag clock spring were faulty and needed to be replaced. The vehicle was not yet repaired. The manufacturer was notified of the failure and informed the contact that the VIN was not included in NHTSA Campaign Number: 17V627000 (AIR BAGS). The contact stated that the vehicle had experienced the failure listed in the recall. The failure mileage was 60,000.

NHTSA ID

11698503

Incident

Aug 1, 2025

Mileage

60,000 mi

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 curb/posts with the front wheels. ‑ Driving over obstacles (e.g. pothole/ threshold/ speed bump/ gully) at an inappropriate speed. 2. Corrosion/ water ingress through a damaged boot (see attachment). ‑ Cracks (1) ‑ High pressure cleaner (2) ‑ Animal bite (3) See various examples listed in the attachments for examples of outside influence. Remedy Remove boot clamps closest to steering gear housing on both left and right (as seen in "Steering Rack Boot Clamp Location"). Pull back boot and inspect for rust, broken end stops, water, or any other anomalies. Replace electric steering. Note: Steering gears replaced due to outside influence or damage must not be claimed under warranty!

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 button being activated accidentally or unintentionally. The recoding can be carried out as follows: 1. Add SA Code O19 into VeDoc (O for Oscar, not "zero") • an XSS ticket may be necessary to add the SA code 2. Perform SCN coding of EIS N73 control unit 3. Deactivate the vehicle key (a successful deactivation is indicated by the LED lighting up 2x briefly and then 1x for a long period). 4. Place the vehicle key in the storage compartment on the key symbol and turn on the ignition. IMPORTANT: all other vehicle keys must be outside the recognition range of the vehicle when doing this! Perform steps 3 and 4 successively for all vehicle keys. Notes: 6th, 7th and 8th generation keys can be deactivated as follows: Up to modification year 22/1 by double clicking the "Lock button" As of modification year 22/1, by press and holding the “Lock button", then double‑click the “Unlock button" at the same time. On model series 167, the storage compartment with the key symbol is located in the armrest. The SCN coding from the EZS is only transferred correctly to the vehicle key under the following conditions: Only one vehicle key is located in the vehicle, this key has been deactivated and it is positioned on the marking in the storage compartment for the data transfer. The costs for this adaptation are to be borne by the customer. For the newer BR 174, 178, 244, 248, 520, and 540, a software update must be initiated, as there is no way to perform SCN coding.

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). This applies to the vehicle regardless of ownership. Why the Warranty extension? On certain Model Year 2018 - 2024 A / C / CLA / CLS / E / G / GLA / GLB / GLC / GLE / GLS / GT / S / SL Mercedes-Benz vehicles, under certain circumstances, the DMTL may trigger erroneous Diagnostic Trouble Code ("DTC") entries that may result in the illumination of the Check Engine Malfunction Indicator Lamp ("MIL"). Any repairs under this warranty extension must be performed by an authorized Mercedes-Benz dealership. • If your preferred authorized Mercedes-Benz dealership performs a diagnosis and confirms that your vehicle has the issue, the repair will be covered under this extended warranty and performed at no cost to you. • This extended warranty does not apply to any other components or conditions beyond the ones mentioned above, and standard warranty terms apply, including the exclusions with respect to extra expenses, as identified in the Service and Warranty Information booklet.

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.

Complaint A popup is seen on the HU with the message "data connection temporarily not available". Potentially affected functionalities in NTG4.5, NTG5 1.Weather 2.Local Search 3.IP Radio 4.Send2Car 5.Speech Detection Service 6.Navigation 7.iHeartRadio 8.Traffic Cams Cause MB Apps is sundowned for all vehicles with NTG4.5 and NTG5 Head Unit Variant. Remedy No support available for NTG4.5 and NTG5 Head Unit Variants for MB App related topics. Note: Please do not create TIPS. Please do not replace any components. HU/Hermes SW update / SCN coding will not fix the issue.

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!