The glass on the panoramic sunroof exploded/shattered under normal driving conditions. It was raining but not too heavy. It didn’t appear that anything hit the glass and no potholes were hit. It seemed to be due to pressure or temperature which caused the explosion which sounded like a loud gunshot and the glass was in pieces. There were no injuries as the sunroof shade was closed and thus the glass fell on the shade. It has not been inspected by dealership or insurance as closed on Sunday and today due to Labor Day, but yes it is available for inspection upon request. However, as it was raining and I needed to get home, I covered the entire sunroof with Duct Tape.
The worst 2017 Mercedes-Benz C450 problems
Ranked by number of owner complaints. Mileage and cost come from what owners wrote.
- Visibility1
- Wheels1
Problems by type
Tap a problem to see which part fails, at what mileage and in which other years.
- Visibility1
- Wheels1
Recalls 1
Electrical system: starter assembly
- What is wrong
- Mercedes-Benz USA, LLC. (MBUSA) is recalling certain 2015-2017 C300 4Matic, C300, CLA250, CLA250 4Matic and CLA45 AMG vehicles, 2017 C300 4Matic Cabrio, C300 4Matic Coupe, C300 Cabrio, C300 Coupe, E300, E300 4Matic, E400 4Matic Wagon, E43 AMG 4Matic, GLA250, GLA250 4Matic and GLC300 4Matic Coupe vehicles and 2016 C350e and GLC300 vehicles and 2016-2017 C450 4Matic AMG Sport and GLC300 4Matic vehicles. In the event that the engine or transmission cannot turn over, the starting current limiter may overheat from the repeated attempts of the starter motor attempting to start the vehicle.
- Risk
- If the starting current limiter overheats, the surrounding components can melt, increasing the risk of a fire.
- Remedy
- MBUSA will notify owners, and dealers will install an additional fuse in the electrical line to the starter, free of charge. The recall began August 31, 2017. Owners may contact MBUSA customer service at 1‑800‑367‑6372. MBUSA's number for this recall is 2017080002.
Recall number 17V114000 · Recall details
See all 1 recalls for the 2017 Mercedes-Benz C450
Defect investigations
Desiccated Air Bag Inflator Rupture
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 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 -- note this information is subject to change/revision as the investigation proceeds). This investigation does not supersede EA15-001, which remains open.
EA21002
Technical service bulletins for the 2017 Mercedes-Benz C450 135
Bulletins tell dealers how to fix known problems. A warranty extension means the manufacturer pays for that repair for longer.
- Visibility/wiper
- Customer complaints relating to automatic transmission 725.0 (NAG3 Classic /9G‑TRONIC automatic...
- Repeat workshop visit for vehicle vibration while braking from 60MPH. NOTE: Although the symptom is...
- Only vehicles with a variable transfer case are affected
- Clanking noise from the area of the speakers in the doors
- Customer complaints relating to automatic transmission 725.0 (NAG3 Classic / 9G‑TRONIC automatic...
- During part of the steering movement, it feels heavier or more difficult to steer in the same spot every time
- Tailgate opens unintentionally
- A popup is seen on the HU with the message "data connection temporarily not available". Potentially...
- This document is intended as a pre-case diagnostic reference for transmission related concerns
What 2017 Mercedes-Benz C450 owners say
Most recent owner complaints, unedited.
- windshield, and I had Satellite repair it through an insurance claim because it was urgent for my safety. - the windshield and its adhesive never bonded together making the windshield structurally unsafe and if I would have gotten into an accident then my vehicles airbags would have not deployed properly. - The issue was brought to my attention from a Satellite repair representative. - yes Safelite who contacted my insurance. - I went through a car wash and found water making its way into my car interior, which I then inspected and found that my windshield was floppy and not attached to my car and how it should.
5 months after recieveing the car I was on the highway and my front passanger side tire air presuure indicator went off. I pulled off the highway and put a "fix a flat" in the tire thinking I ran over a nail. The tire went low again so I drove to the local mercedes benz dealership where they mounted the car and showed me the "fix a flat" gel coming out of the side of the undamaged tire indicating a cracked wheel. They removed the tire and infact I had a cracked wheel. 4 months later my front drivers side air pressure indicator went off where the merdcedes dealership confirmed my second cracked wheel in less than a years time!
Compare the 2017 Mercedes-Benz C450
Other model years
20162017
Questions about the 2017 Mercedes-Benz C450
Is the 2017 Mercedes-Benz C450 reliable?
Owners have filed 3 complaints about the 2017 Mercedes-Benz C450, fewer than a typical C450 model year.
What is the 2017 Mercedes-Benz C450 year score?
The 2017 Mercedes-Benz C450 scores 93 out of 100 (good). The score compares it with the other model years of the Mercedes-Benz C450: 75 is a typical year, 50 means twice the usual complaints, and serious complaints and recalls lower it.
What is the most common problem with the 2017 Mercedes-Benz C450?
Windows, wipers and visibility, with 1 complaint. Next is wheels (1).
How many recalls does the 2017 Mercedes-Benz C450 have?
1 recall, covering electrical system.
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