Oct 24, 2019

What happens when EPS system fails to operate while a car is in motion?

► What happens when EPS system fails? Up-to-date diagnostic equipment and tools by MSG Equipment

Electric power steering (EPS) is a useful invention. Today almost each vehicle is supplied with such a system. EPS significantly facilitates car driving and reduces the effort a driver applies to turn the wheel.

Invention and implementation of EPS not only make driving easier, but it also make it safer. Contemporary EPS models have small dimensions and simple construction.

EPS system failures

EPS is a reliable car element, still failures happen, and it affects the safety. That is why, in case of system failure it must be repaired. EPS sudden failure can be unnoticed by the driver. This happens when error display is not provided.

Carrying out of a simple test can help to diagnose the EPS system condition:

  • Stop the engine and turn the wheel;
  • Start the engine and turn the wheel again.

Compare both effects: when it takes a big effort to turn the wheel in both cases, further diagnostics is strongly required.

It happens sometimes that EPS stops to operate when a speedometer is off. In this case, the most possible reason of failure is the trouble with a speed sensor engaged with both speedometer and power steering. The speed sensor itself can be damaged, and thus, the substitution of the sensor or the wire is required.

EPS repair is needed in case of voltage drop. Undervoltage can as well lead to EPS outage, while in case of overvoltage a surge-voltage protector is included. EPS outage can be caused by a car battery, an alternator or a circuit fault. Regular checkup should be provided for all those car elements.

Why is the EPS behavior sometimes unpredictable?

Sometimes a behavior of the electric power steering is not entirely logical. For example, when the EPS suddenly forces a sharp turn aside during the car straight-ahead driving without any intervention from the driver. This kind of behavior is accompanied by considerable jolts. This is a dangerous situation which can cause a road traffic accident.

As soon as the driver recognizes any symptoms of EPS failure, he should provide diagnostics for his car. Professional auto workshops use special test benches for car units diagnostics which significantly shortens the time of repair.

MS561 Controller is intended to test electric racks, columns and electro-hydraulic pumps of electric power steering. The device can start power steering separately from car electric system, it detects and eliminates errors of power steering control unit. The units can be tested both: in the car or apart from it.

The controller advantages:

  • Quick testing;
  • Built-in power supply with current intensity of 100A;
  • A tablet with installed software (can work with some equipment of VAG Group corporation);
  • The device has OBD II connector for all types of diagnostic scanners.

What actions should be taken in case of EPS outage?

When a steering wheel suddenly became hard to turn while the engine is on, it shows the EPS failure. You can stop the engine and then start it again – the EPS will recover for a while, but this is temporary.

The soonest possible diagnostics and repair in order to restore EPS normal function is highly recommended.