How to fix Mercedes W201 180 fuel pump controller (so called relay)

A fuel pomp relay switches fuel pump for a definite time (usually about 2 seconds) after the ignition have been switched on to make sure that pressure in fuel system is high enough. This can be easily heard as you are starting your car. The relay also detects crankshafts rotations by monitoring signal from primary winding of a ignition coil, so when you turn on a starter the fuel pomp is immediately switch on stays on as long as the engine is running. Here is PCB of that “relay”:

  And here is a closeup of tracks which conducts fuel pump current, I marked this particular two tracks:

Here is solution for the mentioned problem:

I don't know if the same problem occurs in other relay types but i suggest trying to fix it before you buy another one. If the layout of other relay is similar to this it can and it will cause a similar problem. If you have problem with starting your Mercedes you can check if it's a matter of fuel pomp switch by connecting terminals 30 and 87, you can even leave it that way but I wouldn't recommend this solution. In case of an accident - when engine is stopped fuel pomp should be also stopped to prevent fuel leak, if you will “short connect” fuel pomp - it will not.