Dishwasher won't drain

[spike3333]

My Bosch SHE4AM12UC01 Dishwasher stopped draining completely. It's the second time it has done this. Back in Mar 2015 it stopped draining and I replaced numerous components including the Drain Pump, Float Switch, Controller Board and drain line. The drain line finally seemed to fix the problem. I installed a longer line that could loop higher under the sink.

It worked fine again until last week. I found the repair manual for the dishwasher and ran the diagnostic test. The first result stated that the drain pump was not functioning correctly. I removed it and cleared the vanes and reran the test and it passed. Now the result is no error lights which is supposed to indicate a bad aqua sensor. Research says this determines if another rinse cycle is needed and the dishwasher should still function without it working.

If I start a cycle, the dishwasher will drain (I can see a nice flow into the garbage disposal). However, if we run a compete cycle there is standing dirty water in the base of the tub.

Any suggestions on what to do next?

Thanks

 

[cuffs054]

Spike, any chance it's the sink drain that is running slow? My Fridig DW acting in a similar fashion and it was the "P" trap in the sink that was plugged. First and second drain cycle would be ok and then it would start backing up.