This plug connects in place of the faulty Pierburg 6421500494 swirl valve actuator motor and fools the car into thinking that the motor is working.
This is a problem frequently discussed on the forums of these different models.
When the swirl is out of order, the motor goes into a degraded mode, loss of power, motor does not exceed 3000 rpm...
The Swirl can be simply shunted by installing a resistor on the plug that connects to the Swirl motor.
The plug sold here integrates this resistor, you just have to connect it directly to the Swirl connector.
This makes it a simple, clean solution, without soldering or modification.
Once installed, it may be necessary to clear the fault code with an OBDII reader.
You will receive the bypass plug with the integrated resistor. I do not offer instructions as the installation will be specific to your car model, as will the clearing of the fault code(s).
There is already a lot of information on this subject on the net and I don't repair cars, I just sell resistors allowing you to shunt an out of order swirl and get a workaround that is much more affordable than a complete swirl replacement.