Most Common Causes of Electric Power Steering Failures
Long gone are the days when drivers had to exert significant effort to steer a vehicle. Every modern car is equipped with a hydraulic or electric power steering system that makes steering easier for the driver.
The hydraulic power steering system operates by circulating a special fluid in the system and delivering it at the right moment to a specific section of the steering rack.
Electric power steering is a more advanced system whose operation is controlled by electronic control units and numerous sensors.
Principle of Electric Power Steering Operation
Briefly, here's how the electric power steering system operates. After starting the engine, the control unit quickly checks the power steering system: all sensors, assemblies, and overall efficiency are examined. Until the moment the steering wheel starts to turn, the Electric Power Steering (EPS) remains in a resting state, and nothing happens. However, as soon as the driver begins to turn the steering wheel, the electric motor is activated. The electric motor generates auxiliary force, which depends on the steering wheel turning speed and the vehicle's speed. The degree of motor-assisted force is calculated using several sensors:
- Steering wheel turning angle sensor
- Steering torque sensor
- Crankshaft position sensor
- Wheel rotation speed sensor
Definitely, one can quickly get used to the convenience, but it is essential to remember that electric assistance, like any other car system, is prone to malfunctions. Therefore, it's crucial to have knowledge about the main failures and how to prevent them.
Possible Electric Power Steering Failures
Electric power steering does not belong to the simplest systems in terms of construction. Despite this, there are several common malfunctions that a driver should be aware of.
Photo: The steering gearbox is removed from the vehicle for diagnostics and repair.
Damage to Dust Covers
Rubber covers on steering gearboxes are designed to protect the mechanism from dust, moisture, and dirt.
If the dust cover is damaged or not adequately secured with straps, dirt and water will inevitably enter the gearbox. Over time, this will lead to corrosion.
If the steering rack is working correctly but you notice that the rubber cover is torn or improperly secured, the best solution is to take the device to a workshop for inspection. The rack should undergo diagnostics, and the cover along with the straps should be replaced. This procedure is not expensive, unlike the repair of the steering rack. Prolonged use of the rack with damaged covers may result in the need to replace the rack-and-pinion or, sometimes, even purchase a new unit.
Moisture Penetration into the Steering rack
Electric power steering gearboxes differ in construction, but there is always an additional space where electrical equipment is located, including the motor and printed circuit boards.
Initially, the housing is protected against water ingress. However, during vehicle operation, various situations can occur, and sometimes the sealing may be compromised. It is known that water is the main enemy of everything related to electronics.
Water can cause short circuits, burn out the steering control unit, failure of the belt drive, or the electric motor.
Diagnosing the problem before any obvious signs of trouble appear is difficult, so a simple rule is to avoid driving through puddles at high speeds, and obstacles in the form of deep water should be avoided altogether. If you hear noise while turning the steering wheel, contact a workshop for diagnosis as soon as possible.
Sensor Wear
The power generated by the electric motor depends on data obtained from sensors. The most crucial of these is the steering torque sensor.
If the steering control unit receives incorrect data from the sensor, the driver will feel irregular power steering operation. This can manifest in the following ways:
- The driver feels jerking in the power steering.
- Power assistance disappears completely or remains only when turning right or left.
- A yellow or red steering warning light appears on the dashboard (EPS error).
The operation of the electric power steering system is also influenced by sensors from systems that are not directly connected to the steering system. However, their malfunction can change the behavior of power steering, such as when taking turns at excessive speeds.
Natural Wear of the Rack Bar or Motor
Regardless of the quality of the device, there will come a time when it reaches the end of its lifespan.
Wear of rack bars, failure of bearings or motor windings, worn drive belts, damaged bushings—unfortunately, these faults cannot be prevented.
Choosing an electric power steering system
However, careful use of the car, preventive diagnostics, and timely inspections can significantly extend the lifespan of the steering rack and power steering.
EPS Rack Repair
Electric power steering greatly improves driving comfort, but like any other mechanism, it requires additional attention and maintenance. Careful handling and timely maintenance will help the car owner extend the life of the power steering system.
In the event of a failure or malfunction, it is essential to promptly go to a specialized workshop for diagnostics. Typically, repairing the vehicle's steering system is much cheaper if not delayed until the last moment.
Specialists from the STS workshop can help identify and eliminate problems with the steering system. We conduct diagnostics and repairs using our own MSG Equipment devices. Repairs are carried out within 1 working day, and all necessary spare parts are always available in the company's warehouse.
If the device is not suitable for repair, we will propose an appropriate replacement: new or proven remanufactured original equipment. All remanufactures and products are covered by a warranty.
If you still have questions, contact us. Our customer care representatives will schedule a diagnostic appointment or help you choose the right unit for your car. Visit STS for power steering system diagnostics.
