Electronically controlled KDI-21
If you are having control problems with this DW you are probably done unless you can find someone to repair the EC, I remember well when these came out and lots of them did not last long without expensive repairs.
It is possible to switch to a mechanically controlled timer, but you will need a donor KA DW from the 21 series to transfer most of the control panel from as well as the complete wiring harness, it a bit of work but if you are skilled working on major household appliances and such it is doable.
I would only consider switching out the controls if your machine is in excellent early used condition, other wise it will be easier to switch out the entire DW.
John L.