What are the common faults of BMW electronic power steering?
3 Answers
BMW power steering systems can be broadly divided into two categories: one is the hydraulic power steering system, and the other is the electronic power steering system. 1. Hydraulic power steering system. Common causes of the "Power steering failure" warning include: 1. Low power steering fluid, such as hydraulic pipe leakage or damage to the fluid reservoir. 2. Faulty wiring or control of the ECO valve (electronic flow control valve). 3. Power steering pump failure. 4. AL control unit failure. 2. Electronic power steering system. Common causes of the "Power steering failure" warning include: 1. False alarm. You can try stopping the car, turning off the engine, waiting for 10 minutes, and then restarting. 2. Damaged steering torque sensor. 3. Defective or damaged steering gear. 4. Damaged reducer. 5. EPS control unit failure. 6. Faulty wheel speed sensor. 7. DSC control module failure. 8. Wiring faults or poor contact in steering system components, such as loose sensor connectors.
I've been driving a BMW for a few years and have some thoughts on electric power steering issues. The most common problem is the steering suddenly feeling heavier, as if there's no power assist at all—it's like driving with a big rock tied to the steering wheel. This is usually related to the EPS module. BMW uses an electric motor-driven system, and faults in the module or sensors can trigger warning lights, causing the system to automatically limit power assist as a protective measure. Another frequent issue is unusual steering noises, such as squeaking or humming, which might stem from wear in the steering column or rack, or unstable power supply, like an aging battery with insufficient voltage. I've also encountered fault codes in the steering system, such as U0121, indicating communication problems that require diagnosis with a computer. If the steering feels heavy or unresponsive while driving, it's best to pull over and try restarting the car. If that doesn't help, take it to a professional repair shop—never force it to keep driving. Safety comes first. BMW maintenance might be a bit pricier, but professional handling is crucial.
As an auto mechanic, BMW electronic power steering failures are quite common, and I frequently handle such cases. First, check the steering feel – loss of power assistance leading to heavier steering is the most common symptom, often caused by EPS control module failure. In BMW models, the module is located in the engine bay or under the cockpit, making it prone to moisture or vibration damage. Then there are sensor issues – malfunctioning steering angle or torque sensors can cause erratic power assistance or unresponsiveness. On the power supply side, insufficient battery charge or alternator problems can lead to unstable system voltage triggering protection mode. There are also internal mechanical component failures, such as motor or gear set wear, which manifest as jerky steering. During diagnosis, I first read fault codes, check for loose or corroded module wiring and connectors, and test if battery voltage is normal (above 12V). Module reprogramming or replacement may be necessary if required. These issues can affect steering precision or even lead to loss of control if not repaired promptly. I recommend addressing any problems immediately rather than delaying repairs.
