2015 Mercedes-Benz B-Class Problems: 10 Known Issues

On the 2012-2018 Mercedes-Benz B-Class, on certain vehicles, electrostatic discharge combined with a broken clock spring and insufficient grounding of the steering components could inadvertently deploy the driver's frontal airbag. An unintended deployment could startle the driver and cause a crash, and could cause minor injuries. It affects certain 2012-2018 model-year B-Class cars sold in Canada, as listed in Transport Canada recall 2017-490 (the recall also covers C, CLA, E, GLA, GLC and GLK models). A broken clock spring shows a driver airbag warning message and a red airbag warning lamp. Only a Mercedes-Benz dealer can confirm whether a specific VIN is included.

On the 2015-2017 Mercedes-Benz B-Class, on certain vehicles, the occupant classification system may not work properly. It could turn off the front passenger airbag with an adult in the seat, or leave it on with a child seat installed, increasing the risk of injury in a crash. It affects certain 2015-2017 model-year B-Class (W246) sold in Canada (B 250), as listed in Transport Canada recall 2019-632 (Mercedes-Benz recall 9190204), which also covers the CLA. Only a Mercedes-Benz dealer can confirm whether a specific VIN is included.

On the 2015 Mercedes-Benz B-Class, on certain vehicles with the Easy-Vario rear seat option, the rear screws that bolt the rear seat to the body may be missing on one side. In a crash, the rear seats may lift up from the body and the seat belt anchoring may not function as designed, increasing the risk of injury. It affects certain 2015 model-year B-Class (W246) sold in Canada with the optional Easy-Vario rear seat, as listed in Transport Canada recall 2016-157. Cars without the option are not affected. Only a Mercedes-Benz dealer can confirm whether a specific VIN is included.

On the 2015 Mercedes-Benz B-Class, on certain vehicles with a 4-cylinder gasoline engine, a weld on the camshafts may not have been placed at the intended position. The camshaft could break and damage the engine, causing it to stall, which would increase the risk of a crash. It affects certain 2015 model-year B-Class (W246) cars with the 4-cylinder gasoline engine sold in Canada (B 250), as listed in Transport Canada recall 2015-463, which also covers the CLA and GLA. Only a Mercedes-Benz dealer can confirm whether a specific VIN is included.

On the 2012-2018 Mercedes-Benz B-Class M270 DE16 1.6L turbo, owners of W246 B-Class cars with the 1.6-litre M270 petrol engine report a rattle at start-up and stretched timing chains. One B 180 was diagnosed by a Mercedes workshop with a stretched chain at 75,000 km, 2012 1.6-litre cars needed a new chain and sprockets (one also a camshaft adjuster and cylinder head), and a pre-facelift B 180's chain apparently jumped, damaging the engine. It affects second-generation (W246) B-Class cars with the 1.6-litre M270 petrol engine (M 270 DE 16: B 180 and B 200), model years 2012-2018; these were not sold in Canada. One further report concerns a 2.0-litre B 200 Natural Gas Drive whose cold-start rattle returned after a tensioner replacement; no report was found for the 2.0-litre B 220 or B 250, and a forum regular says none has been posted. The diesel and electric models are not affected. Owners reported the problem at 26,000 km (about 16,200 miles), 75,000 km (about 46,600 miles) and 80,000 km (about 49,700 miles).

On the 2013-2019 Mercedes-Benz B-Class, on certain vehicles, the power steering control unit may corrode, letting moisture in so that it fails. That could cause a loss of power steering assist and a sudden increase in steering effort, especially at low speed, increasing the risk of a crash. It affects certain 2013-2019 model-year B-Class (W246) sold in Canada (B 250) that were originally sold or ever registered in areas of heavy road salt use (Ontario, Quebec, New Brunswick, Nova Scotia, Prince Edward Island and Newfoundland & Labrador), per Transport Canada recall 2020-617 (Mercedes-Benz 4694202) and its expansion 2021-507 (Mercedes-Benz 4694203); CLA and GLA are also listed. Only a Mercedes-Benz dealer can confirm whether a specific VIN is included.

On the 2015-2017 Mercedes-Benz B-Class, on certain vehicles, if the starter is blocked, a very high current could flow through the starting current limiter during repeated starting attempts. It could overheat and melt surrounding components, increasing the risk of fire. It affects certain 2015-2017 model-year B-Class (W246) sold in Canada (B 250), as listed in Transport Canada recall 2017-062 (also C, E, CLA, GLA and GLC). Only a Mercedes-Benz dealer can confirm whether a specific VIN is included.

On the 2012-2019 Mercedes-Benz B-Class, owners of W246 B-Class cars with the 7G-DCT dual-clutch automatic describe a pause of about a second before the clutch bites when pulling away, and jerking or harsh shifts at low speed. One owner of a high-mileage 2014 B 220 CDI reports judder that a transmission reset did not cure; the cause was not diagnosed in the thread. It affects the second-generation (W246) B-Class with the 7G-DCT automatic: model years 2012-2018 in Europe and 2013-2019 in Canada (B 250), with the M270 petrol (1.6 and 2.0 litre, including the B 200 Natural Gas Drive), OM651 diesel or OM607 1.5-litre diesel. The owner reports linked here are from a B 200, a B 200 CDI and a 2014 B 220 CDI. Not the B250e electric (W242), which has a single-speed drive unit, and not manual-gearbox cars. Mileage when it happened, as stated in the linked owner reports: 3,200 km (about 2,000 miles), 110,000 km (about 68,400 miles) on a 2016 and 230,000 km (about 142,900 miles) on a 2014.

On the 2012-2019 Mercedes-Benz B-Class, w246 owners report a parking-brake malfunction warning, and in one case the electric parking brake worked on one side only. One owner found water in the left rear actuator motor and replaced both actuators, but the warning stayed until the parking-brake control module connectors inside the right rear of the car were unplugged and reseated. It affects the second-generation (W246) B-Class with the electric parking brake: model years 2012-2018 in Europe and 2013-2019 in Canada (B 250). The owner reports linked here include a 2012 car. Owners report the rear actuator motors, the wiring and the control module as the parts involved; the cause on a given car must be diagnosed.

On the 2012-2019 Mercedes-Benz B-Class, owners of W246 B-Class cars with the M270 petrol engine report coolant warning messages, an engine warning light with the temperature stuck around 70-80 C, or the gauge swinging, with dealers replacing an electronically controlled thermostat that stuck open. Some gauge movement is normal on this engine, and owners report a dealer engine-software update that steadied it where no hardware fault was stored. A thermostat replacement did not always cure it: other causes found were a crack elsewhere in the cooling system and a stuck valve in the water pump. It affects the second-generation (W246) B-Class with the M270 petrol engine (B 180, B 200, B 220 4MATIC, B 250): model years 2012-2018 in Europe and 2013-2019 in Canada (B 250). The owner reports linked here are from a B 220 4MATIC, a 2012 B 200 and other W246 petrol cars. Not the diesel or electric models. Mileage when it happened, as stated in the linked owner reports: 65,000 km (about 40,400 miles) on a 2013, 74,000 km (about 46,000 miles) on a 2012, 142,000 km (about 88,200 miles) on a 2012 and 176,000 km (about 109,400 miles) on a 2012.