What Causes the Power Steering Fault Display on the Mercedes Dashboard?
3 Answers
Mercedes dashboard displaying a power steering fault can be caused by heavy steering, steering noise, or steering system oil leakage. Heavy Steering: The power steering system contains a large amount of air. It is necessary to inspect the steering gear, steering pump control valve, oil cup filter, steering fluid, and clean the entire power steering system. Steering Noise: Excessive load operation of the steering system, excessive wear of the stator and rotor inside the steering pump, leading to irregular movement of the oil in the pump, resulting in noise. Steering System Oil Leakage: Loosening of connecting parts and joints in the power system and steering system causes leakage. It is necessary to replace the sealing ring at the interface between the oil pipe and the steering pump, and replenish the power steering fluid if the oil level is below the specified value.
Recently, my Mercedes-Benz also displayed this fault warning, and it took me quite a while to figure it out. The main issue lies with the electronic power steering system—it could be due to moisture or poor contact in the control module's circuit board, especially during the rainy season. Additionally, severe wear on the power motor's carbon brushes can also trigger an alarm, something older cars should pay special attention to. If the fault warning appears right after going over a speed bump, it might be that the torque sensor was shaken loose. When the steering wheel becomes heavier, avoid forcing it as it can easily damage the gear set. It's best to immediately connect to a diagnostic tool to check the fault codes. If a regular repair shop can't handle it, you'll need to visit a dealership for decoding, as Mercedes' electronic systems are particularly sensitive. Sometimes, replacing the entire steering column assembly may be the only permanent solution.
Last time this light came on in my car was during a long-distance drive, when the steering wheel suddenly became as heavy as lifting bricks. I asked an experienced auto mechanic, and he said there are several common causes: the solenoid valve in the steering gear might be stuck, especially prone to freezing in northern winters; or the fuse in the power steering system might have blown, located in the fuse box near the driver's footwell; it could also be an interrupted signal from the wheel speed sensor, since electronic power steering requires real-time speed data. Another often overlooked point: low battery voltage can also trigger a protection mode. If you want to handle it yourself, first try turning off the engine, locking the car, waiting five minutes, and restarting. If that doesn't work, check if there's any foreign object stuck in the steering linkage near the tires. If it still doesn't resolve, you'll need professional equipment for diagnosis.
