Stepper motor - signs of malfunction and breakdown. How to clean a stepper motor in a car?

In gasoline internal combustion engines, a stepper motor is located near the throttle valve. This is a small device that controls the idle throttle position so that the unit does not stop working when the accelerator pedal is released. It constantly adapts its operation to the current engine parameters, ensuring optimal speed. Read on to learn about the design and operation of a stepper motor in a car. 

What is a stepper motor?

Simply put, a stepper motor, referred to as a stepper valve or slow-acting valve, is an electric motor that rotates a rotor through certain angular values ​​based on the pulses applied. In internal combustion engines, several elements affect its operation, including:

• Coolant temperature;
• crankshaft position sensor signal;
• MAP sensor readings;
• information about the ignition on;
• battery level.

Thanks to the above variables, the stepper motor does its job, adapting to the temperature of the motor or the need for additional battery charging. 

How does a stepper motor work?

The principle of operation of a stepper motor is based on the interaction of the excitation rotor, power connector and rotary valve. The device monitors the polarity of the current supplied to the power supply, and thus determines the setting of the angle of inclination.

Engine speed is controlled by more than just the accelerator pedal. There are times when you need to do this without his participation, such as standing in a traffic jam or approaching a traffic light. It is important that it is not only about maintaining the speed at a given level, but also about managing the operation of the engine in such a way as to maintain battery charge, the operation of all systems and at the same time burn as little gasoline as possible. RPM may vary depending on engine temperature and battery charge level.

Rotational turbulence - signs of failure and damage to a stepper motor

Faults and damage to the step valve are easy to recognize. The stepper motor shows signs of failure by fluctuating at idle speed or constantly increasing it, for example, when approaching a traffic light. Agree, it can be annoying when you can’t lower them and the car starts to howl mercilessly at high speeds. In many cases, this block behavior is caused by incorrect operation of the stepper motor.

What to do if you notice symptoms of stepper valve damage?

There are several ways to deal with a damaged stepper valve. Let's start with the fact that in many cases repairs are able to do on their own. It's about cleaning the stepper motor. Below we describe this process in detail.

Cleaning or replacing a stepper motor?

If you are in doubt whether it is better to clean or replace the stepper motor, check the condition of this part. Look for a stage valve near the throttle. It can be integrated with another part of the suction system, so you should always look for a stepper motor in this area. It is important to note that replacing a stepper motor is in many cases unnecessary. It often turns out that the incorrect operation of the stepper motor is caused by contaminants that accumulate inside this element.

How to clean a stepper motor?

Start cleaning the stepper motor by disassembling the individual elements. Find a clean place where you can easily take it apart. After thoroughly cleaning all parts of the stepper motor, lubricate those that are responsible for pushing the plug. If you put everything back in the correct order, you can put the idle valve in place.

Step valve adaptation

Putting the parts in place and running the unit, you will notice that not everything works as it should. This is because the stepper motor needs to be adapted. How to do it? Turn the ignition on and depress the accelerator pedal several times and slowly release it. In some car models, this method is quite sufficient and allows you to return to the factory settings of the stepper motor.

However, sometimes more needs to be done. If the engine speed is still fluctuating, start the engine and let it idle for a few minutes. This may cause it to "get" the device's settings and start working as expected. Another option is to go the route for 15-20 km. It is also a form of element adaptation. If all this does not help, the stepper motor will probably need to be replaced. However, before doing so, try to exhaust all available options.

The work done by a stepper motor is very important. Importantly, its design is so simple that you can clean the stepper motor yourself. If this does not help, you will unfortunately have to replace the stage valve. Fortunately, it's not expensive.