Skoda Octavia A5 1.8 TSI DSG 7 0AM (DQ200). Replacing the clutch actuator solenoid.

Describing the problem.
When driving in Drive mode, thumps are felt when shifing to even gears. I.e. when shifting from the first gear to the second - the thump and when shifting from the third to the fourth -jerk. In some cases, after the next jerk, the box entered the emergency mode (flashing key on the dashboard).
Diagnostics.

To select the strategy for troubleshooting the automatic transmission, first of all,  a diagnostic tool is used. Reading errors in our case showed the code P176F (Clutch 2 is inadvertently closed sporadically). Most often this code indicates the unstable operation of the clutch actuator solenoids that are part of the gearbox electrohydraulic  control unit. In the picture below, the pointers to the problem solenoids are marked in red.


Troubleshooting..

Removal of the gearbox electromechanical  control unit (mechatronic).

Disassembly and washing of mechatronics. Visual assessment of the condition of the body of the valvebody for the presence of characteristic defects.

Removal of solenoids for testing on a special test bench.

Stand for testing the operation of solenoids

Installing a solenoid for testing

All solenoids are tested sequentially. The schedule of a working solenoid is:

And this is a work schedule of a failed (not stable) solenoid

During the tests, a failed solenoid with unstable operation was detected. This solenoid controls the clutch K2 (second primary shaft) on which the second and fourth gears are located. I.e. unstable operation of the solenoid caused the jerks in the operation of the gearbox. This solenoid must be replaced.

After replacing the solenoid, mechatronics is assembled and a preliminary check of its hydraulic system is performed. The operation of the engine of the oil pressure pump is checked, diagnostic conditions are read. After the diagnostic tests, the mechatronics is installed and connected to the gearbox.

Result.
After replacing the solenoid, the box's operation stabilized. Jerks when switching the second and fourth gear are not observed.