Problems with the Mercedes B250e
Reliability Mercedes B250e: common problems, issues symptoms and faults
- Problems with the high-voltage electrical system insulation: These can occur in rare cases and are usually due to a fault in the high-voltage battery. They do not occur at a certain mileage.
- Error in the electric drive system: A communication fault can cause the drive unit to shut down, resulting in a temporary loss of driving force. Around 2600 vehicles from the 2014-2015 model years were affected.
- Problems with the coolant pumps: Malfunctions of the coolant pumps can cause error messages in the drive system. These problems can occur as early as 30-50,000 km.
Problems with the Mercedes B250e due to coolant leakage in the drive unit
A common fault is a failure of the rotor seal, causing coolant to enter the drive unit. This causes corrosion and can destroy the stator and/or inverter. The first signs can appear as early as 30-50,000 km.
Regular inspection of the drive unit for coolant leaks. If a defect occurs, the affected components such as seals, bearings and possibly the entire electric motor must be replaced.
Some owners report a faster than expected loss of capacity. The range can decrease noticeably within the first 50-80,000 km.
Regularly check the battery's health with an OBD reader. Adjusting charging cycles and habits can help to extend its lifespan. In some cases, replacing the battery or individual modules may be necessary.
Problems with the Mercedes B250e: on-board charger
The onboard charger can fail, leading to charging problems. This can occur at relatively low mileage, as early as 20-40,000 km. Symptoms can include slow charging or even a complete inability to charge.
Problems with the Mercedes B250e: electrical drive system
A communication fault in the electrical drive system can cause the drive unit to shut down, resulting in a temporary loss of driving power. This problem affected approximately 2600 vehicles from the 2014-2015 model years.
An official recall was initiated, during which dealers updated the electrical drive system software free of charge.
Problems with the Mercedes B250e: error code ‘U05959A’
Some owners report problems starting the vehicle, accompanied by the error code ‘U05959A’. This indicates that the control unit ‘Electric Machine A’ has shut down the system.
A comprehensive diagnosis by a specialist workshop is required. Possible causes may include problems with the battery, the electric motor, the wiring or the control units. In some cases, a software update of the affected components can help.
Faults of the infotainment system with the Mercedes B250e
Software errors or display problems can occur within the first 30,000 km. Regular software updates can help to minimise these defects and dropouts.
Problems with the Mercedes B250e: electric tailgate (if available)
Models with an electric tailgate can experience sensor errors or mechanical problems, often within the first 30-50,000 km.
Additional common faults with the Mercedes B250e
Based on the reviews of Mercedes B250e drivers, we present an overview of additional possible complications:
- Rapid battery discharge when the vehicle is not used for long periods: Some owners report a gradual battery discharge when the vehicle is not used for long periods. A specific mileage is not known for this.
- Defects in the air conditioning system: Failures or reduced cooling performance of the air conditioning system can occur, especially in older models. A typical mileage that would favour the occurrence is not known.
- Charging system difficulties: Malfunctions of the onboard charger or charging electronics can lead to extended charging times or charging difficulties. These problems can occur in the first few years.
The following list provides an overview of the most common problems with the Mercedes B250e. It is also important to note that not every vehicle is affected by all of the complications mentioned and that regular maintenance can prevent or minimise many of these vulnerabilities.
4 November 2024 
