2021 Mercedes-Benz GLS450

The 2021 Mercedes-Benz GLS450 is a luxury SUV known for its spacious interior, comfortable ride, and advanced technology. The GLS450 comes standard with a 3.0-liter turbocharged inline-6 engine producing 362 horsepower and 369 lb-ft of torque, paired with a 9G-TRONIC 9-speed automatic transmission. A more powerful GLS580 model is also available with a V8 engine. Owners generally praise the GLS450’s luxurious features, smooth ride, and ample cargo space. Common complaints include the complexity of the infotainment system, occasional electronic glitches, and higher maintenance costs.

Engine

3.0L Turbocharged Inline-6 (M256)

• 48V Mild Hybrid System Issues
  • Description/Symptoms: The 48V mild hybrid system, which powers the vehicle’s auxiliary systems and provides an electric boost, can experience failures. Symptoms include warning lights, reduced power, and the inability to start the engine.
  • Solution: Diagnosis often involves checking the 48V battery, integrated starter generator (ISG), and associated control modules. Replacement of the faulty component is usually required.
  • Estimated Cost to Fix: $1,500 - $4,000+ depending on the component requiring replacement
  • Recalls: None Found
• Oil Leaks
  • Description/Symptoms: Oil leaks from various engine seals and gaskets. Common areas include the valve cover gasket and the oil filter housing. Symptoms include visible oil leaks and oil consumption.
  • Solution: Replacement of the leaking seals or gaskets.
  • Estimated Cost to Fix: $200 - $1,000+ depending on the location and severity of the leak.
  • Recalls: None Found

Transmission

9G-TRONIC 9-Speed Automatic (725)

• Rough or Delayed Shifting
  • Description/Symptoms: Some owners have reported experiencing rough or delayed shifting, particularly between lower gears. This can manifest as jerky acceleration or a noticeable lag when shifting.
  • Solution: In some cases, a software update can resolve the issue. In more severe cases, valve body replacement or complete transmission replacement may be necessary.
  • Estimated Cost to Fix: $200 (Software update) to $5,000+ (Transmission replacement)
  • Recalls: None Found

Suspension

• Air Suspension Malfunctions (AIRMATIC)
  • Description/Symptoms: The AIRMATIC air suspension system can experience failures, leading to ride height issues, uneven suspension, or the inability to adjust the suspension settings. Warning lights may also illuminate.
  • Solution: Diagnosis involves checking the air struts, air compressor, and control modules. Replacement of the faulty component is typically required.
  • Estimated Cost to Fix: $1,000 - $3,000+ depending on the component needing replacement.
  • Recalls: None Found

Electrical

• MBUX Infotainment System Freezing/Crashing
  • Description/Symptoms: The Mercedes-Benz User Experience (MBUX) infotainment system can experience freezing, crashing, or slow response times. This can affect navigation, media playback, and vehicle settings.
  • Solution: A software update is often the first step in addressing these issues. In more severe cases, the infotainment system module may need to be replaced.
  • Estimated Cost to Fix: $0 (Software Update) - $1,500+ (Module Replacement)
  • Recalls: None Found
• Sensor Malfunctions (Parking Sensors, Blind Spot Monitoring)
  • Description/Symptoms: Malfunctions with parking sensors or blind spot monitoring systems. Symptoms include false alarms or the system not functioning at all.
  • Solution: Replacement of the faulty sensor.
  • Estimated Cost to Fix: $200 - $600+ per sensor
  • Recalls: None Found

Exterior

• Automatic Tailgate Issues
  • Description/Symptoms: The automatic tailgate may fail to open or close properly.
  • Solution: Diagnosis involves checking the tailgate motor, sensors, and hinges. Replacement of faulty components will resolve the problem.
  • Estimated Cost to Fix: $300 - $1000+ depending on the repair.
  • Recalls: None Found

Interior

• Sunroof Malfunctions
  • Description/Symptoms: Sunroof not opening or closing smoothly, or at all. Issues with the sunroof motor or track.
  • Solution: Repair or replacement of the sunroof motor or track.
  • Estimated Cost to Fix: $300 - $1200+
  • Recalls: None Found

Summary:

The 2021 Mercedes-Benz GLS450, while a luxurious and comfortable SUV, can experience several issues. The most common reported problems revolve around the electrical systems, particularly the MBUX infotainment system and the 48V mild hybrid system. Air suspension malfunctions are also a potential concern. While most issues are not considered catastrophic, the cost of repair can be relatively high due to the complexity of the vehicle’s systems and the need for specialized parts and labor. Potential buyers should be aware of these potential issues and consider extended warranty options.