Mercedes Benz is a luxurious car brand, and its B-class was launched in about 2005. It is the upgradation of the class A vehicles with modern interiors and exteriors. However, the second generation of B-class was launched in 2011 with various petrol and diesel engines. Moreover, some of the second-generation cars are hybrid and electrical, and many people complain about problems with their parts.
Mercedes Benz B-Class problems include airbag incorrect deployment, less ground clearance, electric system failure, turbocharged engine failure, increased fuel consumption, engine control unit failure, frequent limp mode activation, noisy transmission, and knocking sound from the front suspension.
My friend has the B-Class 2007 model, and he faced many issues because of the electric and mechanical failures. He told me he experienced problems that did not come under the warranty. The company provided an extended warranty to their customers because of the low reliability. He told me he spent hundreds of dollars repairing their faulty components monthly.
| Problems | Solutions |
| Airbags incorrect deployment | Replace airbag sensors |
| Less ground clearance | Add large tires or lift kit |
| Electric system failure | Check batteries, alternators and starter motor |
| Turbocharged engine failure | Hire mechanic for turbocharged inspection |
| Increased fuel consumption | Check fuel injector’s O-rings |
| Uncomfortable passenger seats | Add high-quality seat cushions |
| Engine control unit failure | Replace engine control unit |
| Frequent activation of limp mode | Keep particulate filters clean |
| Noisy transmission | Purchase new gearbox |
| Wear and tear of seat belts | Change frayed seat belt straps |
| Knocking sound from the front suspension | Replace anti-roll bar brushes |
Airbags incorrect deployment
Many people complain about the erratic deployment of airbags in their cars. Airbag deployment in their vehicles occurs without any collisions or accidents.
I owned the 2014 CLA250 and faced the same issue. I was driving on the highway, and my car’s airbags came on without any collision. However, I did not face serious injuries on any body part, but I felt a burning sensation on my arm and hand. A burning sensation came because of the chemicals released from the airbags.
They deploy erratically because of the failure of sensors. The issue comes from malfunctioning the computerized system that activates the airbag sensors.
You should avoid driving after seeing the airbag warning light on your dash screen. Illuminated lights show the issue in the sensor and airbag system.
It is better to replace faulty airbag sensors with new ones for their correct deployment and reduce the chances of injury to major body organs. You need $350 to $400 for the replacement of airbags, including mechanic costs.
Less ground clearance
People complain about poor ground clearance in some of their vehicles, which causes issues while driving on unpaved and uneven terrains. My brother had a Mercedes Benz B-class B200 and always faced problems while driving on uneven roads because of its lower ground clearance.
The interior of that car was roomy and quite comfortable. He told me that he was moving over the speed bump, and the undercarriage of his car collided badly with a raised surface because of less ground clearance.
Vehicles with less ground clearance have better mileage, but hitting potholes can affect the suspension parts and wheel alignment.
You cannot use these cars off-road because they are closer to the ground. My brother wanted to sell his car, but I recommended replacing their pre-existing tires with larger ones or installing a suspension lift kit to increase the height.
Electric system failure
You can also face electric system issues in B-class vehicles, which can affect the functioning of the electric components and lead to their failure.
Electric system failure also causes loss of power because of failure of ignition switches, spark plugs, and engine sensors. Power system failure comes from damaged electric connections, poorly charged batteries, and failed alternators.
You cannot use the features of lights, air conditioners, touch screens, and infotainment. Electric system failure comes from a faulty starter motor that does not allow the engine to ignite.
The issue is common in B-class first-generation vehicles launched from 2005 to 2011. You should inspect their batteries, alternators, starter motors, and wiring harnesses.
Turbocharged engine failure
Turbocharged are powerful engines that contain turbocharged devices for power ignition. These include devices that allow more air induction in the combustion chamber to increase power from the engine.
Mercedes Benz B-Class second-generation cars launched from 2011 to 2019 are vulnerable to turbo failure. Turbocharged engines become less efficient, which decreases the overall power output.
Wear and tear chances of turbocharged engines increase because of their extended and regular use. In addition, the issue also comes because of their poor maintenance.
You can face problems when you do not change engine oil regularly. Hiring an expert mechanic to inspect turbocharged engines and identify the problem is better.
Increased fuel consumption
Many people complain about the increased fuel consumption issues in the Mercedes Benz B-Class. It can affect the overall fuel economy and your daily budget.
Moreover, you can also feel the fuel smell from your car’s interior and exterior side. You can hear the huffing sound when you start the engine and increase the speed.
Oil consumption increases because of the damaged O-rings of fuel injectors that do not allow these devices to control fuel induction in the combustion chamber.
Inspect the O-rings and replace the damaged rubber seals with new ones. Select the seals of the correct size and high-quality rubber material.
Uncomfortable passenger seats
First-generation Mercedes Benz B-Class cars have many problems. Many people complain about its uncomfortable passenger seats. You cannot enjoy the long trip because of unpleasant feelings.
These can also make you tired, and you feel muscle pain. These seats are uncomfortable because of low-quality cushions. Moreover, these can also become uncomfortable because of their regular usage for extended periods.
You can fix it by replacing the factory-installed low-quality seat cushions with high-quality ones.
Engine control unit failure
Engine control units are also vulnerable to failure in the second generation of the Mercedes Benz B-Class. You can have difficulty starting the engine because of ECU failure.
You can hear vibrations while accelerating at high speed. Engine control unit failure comes because of bad electric wirings and water-related damages.
You can replace the faulty engine control unit with a new one. Select the engine control unit compatible with the specific vehicle of the Mercedes Benz B-Class.
Frequent activation of limp mode
I faced the frequent limp mode activation problem in my Mercedes Benz 2008 model. I experienced that air conditioners and other electric components in my cars stopped functioning suddenly because of a lack of power from the engine.
I inspected the engine parts to find the root cause of the loss of power. The particulate filter in the engine compartment was badly clogged, limiting the fuel supply and causing a loss of power.
I removed the particulate filter, cleaned it, and installed it to resolve the issue.
Noisy transmission
You can see several issues with transmission components because of the electric and mechanical malfunctioning. Transmission issues are more common in the third generation of the Mercedes Benz B-Class launched in 2019.
You can hear the grinding and crunching noise while shifting gears because of the fault in the gearbox. Moreover, people also complain about the hard gear shifting and sudden disengagement of the gears.
Replacing the faulty gearbox with a new one is necessary to improve your safety on the road. Purchase the new gearbox from dealerships and replace it with pre-existing ones.
Wear and tear of seat belts
Seat belt straps are made of low-quality fabric, which is vulnerable to fraying and ripping because of their age and regular usage.
Seat belt replacement is expensive, and these parts do not come under warranty.
However, you can replace the seat belt strap with a new one to increase safety during driving. Ripped straps can come off the release mechanism and compromise safety during sudden braking.
Knocking sound from the front suspension
People usually complain about the knocking sound from the front suspension parts while moving over bumpy roads. I also faced the same problem with my Mercedes Benz B-Class and thought it came from damaged struts and absorbers. However, I inspected the front suspension parts and saw damaged anti-roll bar brushes.
I found that a knocking sound was coming because of metal-to-metal contact and the failure of rubber brushes. Anti-roll bar brushes are installed between the metal parts to decrease the friction and their direct contact.
You should inspect the rubber brushes frequently and replace the worn-out rubber washers with new ones.
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