Pump is always running on my Asko D3121 even when door is open. the pump works OK when I put water in dishwasher but never stop

test switch-circuit board for short or failure

you seem rushed
ok
the problem might not be in your senser or timer but in the pump its self

check if there is no water leakeage under if not check the micro switch found under the set

All power and sounds should stop when any dishwasher door is opened.
Your door switch may be stuck causing it to continue.
The 90 second sound at the beginning of the cycle is the water pump extracting any residual water before taking on clean water for the wash cycle.
Any excessive noise from the drain pump could be debris in the pump. e.g. broken glass.
You can remove the pump and check it for blockage or any foreign object.

This seems to be that the Anti Flood system has triggered. This device detects water leaks / spills to the bottom of the washer and automatically puts the washer in pump out mode and shuts off the water inlet. The device is made up of a pollystireene float and micro switch that activates once the float detects any leaks / spillage. Dry water and check for leaks and this should solve the problem

put it out from the source. check the pump to see if there is anything wrong with it. you can change the pump if there is a damage on it.

I had tried several failed attempts to fix this problem. Finally I got on my knees and asked God to make the dishwasher run in Christ's name. The dishwasher just completed it's first cycle without any problems.

Solved by draining water from bottom pan.

I had to slide the dishwasher forward (undercounter installation)and tip it forward as far as possible. Water leaks onto floor, but then the internal controller seems to reset and the ASKO now works normally again. What kind of idiot would design a control module that does not incorporate a power-off interlock? FAIL FAIL FAIL - Bad, ASKO, Bad. Go to your room.

Ok, heres what you have to do. Remove the lower toe kick and then remove the panel behind that to gain entry to the lower portion of the dishwasher wher the guts are. You will also have to pull out the little brackets that hold the toe kick and all the screws will be t-15 or t-20 torx (little star shaped bits) Once you have all the panels out of the way, you will find water in the bottom of the tray there tripping the overflow switch. Remove the water with a wet vac or towel or something and the drain pump will stop running. If you can't or don't want to do all this, then just let the dishwasher sit for a few days or so and eventually the water will just evaporate and everything will work normally. Hope This Helps!