If you are getting a “power steering malfunction” fault message on your Mercedes dashboard, you are not alone.
This is one of the common problems that Mercedes owners face. Here are a few things you need to know about this problem, its causes, and how it can be fixed:
What is Mercedes Power Steering?
Before we dive into what this fault message means and the leading causes it is important to first understand what power steering is.
You are likely accustomed to the effortless steering experience that comes with power steering. Power steering is a system that helps you steer your vehicle by reducing the amount of effort it takes to turn the steering wheel.
Without power steering, you would need to use a lot of force to turn the wheels, especially at low speeds or when parking.
There are two types of power steering systems: hydraulic and electric. Hydraulic power steering systems use a pump to pressurize hydraulic fluid, which is then sent to the steering gear to assist with steering.
Electric power steering systems use an electric motor to provide the assistance needed to turn the wheels.
A lot of Mercedes Benz models are equipped with electric power steering (EPS), which is a new technology that uses an electric motor that is attached to the steering rack/steering to move the steering wheel.
The EPS uses a set of sensors to monitor the position of the car and adjust the electric motor accordingly.
When you turn your steering wheel, this will send a signal to the EPS system which then tells it how much power should be applied to each wheel for optimal assisted turning.
What Does “Power Steering Malfunction” Mean on a Mercedes?
When you see the “power steering malfunction” on your dashboard.
This means that your Mercedes power steering system has failed and as a result, you will feel the steering getting harder to turn due to the lack of assistance.
What Causes Power Steering Malfunctions on a Mercedes?
Now, let’s look at the potential causes based on my experience as an auto technician.
1. Damaged Electric Power Steering Motor:
The EPS motor is one of the most important components in your power steering system.
The electric power steering motor is responsible for turning the steering wheel.
If it malfunctions or is damaged, the power steering system will stop working and the “power steering malfunction” warning light will come on.
2. Bad Electric Power Steering Sensor(s):
The power steering system on a Mercedes relies heavily on the electric power steering sensor to communicate with the EPS system.
Since the system is electric, it requires sensors to communicate with the power steering pump and assist motor. If one of these sensors is damaged or faulty, it can cause this fault.
3. Bad Steering Rack:
The steering rack (rack and pinion) is the component that connects the steering wheel to the wheels of your Mercedes.
The steering rack can get damaged due to outside temperature changes, a collision or excessive wear and tear on the vehicle.
If there is damage to the steering rack, it will not be able to properly communicate with other parts of the power steering system as a result your Mercedes will display a “power steering malfunction warning”
If the Rack is damaged you will need to have it replaced to fix the issue, in general, it costs around $600-800 (£ 480-640) to have it replaced.
4. Battery Issues:
Since most Mercedes use Electric Power Steering instead of Hydraulic Power Steering, a dead battery can cause a “power steering malfunction” warning.
If your car is not getting power from the battery because it has been drained or its damaged, certain functions will be disabled including the power steering.
This can be fixed by having a new battery installed or by jumping your vehicle from another car that has a charged battery.
5. Electrical Problems:
The last common cause of this fault is an electrical problem with the car
If there is an electrical problem with the Mercedes, it can cause the power steering to malfunction.
For example, if there is damage to the fuse box on your car and some of its components are not receiving power.
They will not function properly including those associated with the power steering system such as sensors and pumps.
Common Signs of a Mercedes Benz Power Steering Malfunction
Unusual Noises When Turning
One of the most proficient signs of power steering malfunction is unusual grinding/whining sounds.
If you hear a whining or grinding noise when you turn the steering wheel, it may be a sign that the power steering system is failing.
The noise may be caused by a damaged power steering motor or a bad power steering rack (in other words mechanical issues)
Another sign of power steering malfunction is difficulty steering.
If you find it hard to turn the steering wheel, especially at low speeds, it may be a sign that the power steering system is failing.
What to Do When You Get a “Power Steering Malfunction” Warning
I recommend that you take your vehicle to the nearest Mercedes dealer or independent garage as soon as you get this warning.
The problem could be minor, but it will need a proper diagnosis using a scanner and repair from an experienced technician.
The reason for this is that the power steering system is a complex piece to understand, and it’s an important part of your vehicle. It’s best to leave it to the professionals.