Bosch Control board problem - fill & drain, fault #4
I replaced the control board to correct a problem with the soap dispenser. The soap door stopped opening. The dispenser has also been replaced but both the original and replacement units tested good. The soap door will will open if 120V is applied. On further testing it looks like the original control board was not providing the actuating signal.
I replaced the control board but now the dishwasher has a different problem. It runs for about 3 minutes and then does 4 short (5 second) drain cycles. I can see water being purmped out in the sink disposal. After a few more minutes the 4 short drains repeats. The washer does not progress any further. I have to to a "cancel and drain" to stop it. When I run the diagnostic on the new control board I get error #4 (fill error). I reported this and was sent another control board, Same thing.
I re-installed the the original board (which passes the diagnostic) and the can run the dishwasher again but still have to manually open the soap dispenser.
The original and replacement control boards look the same (no obvious jumpers, etc) and when I installed the new boards I did a "cancel and drain" to see if that might help. Is there any special setup or reset that is needed when installing a new control board?
21-Jan-2013 -Added note: The wiring harness on my machine does not include a wire for pin 4 / connector 4. According to the diagrams I have downloaded this is one path for the float switch to connect to the control board. Could there be some variation like mine without the pin 4 wire that requires a different version of the control board or jumper somewhere?
Last edited by nn4zz : 01-21-2013 at 03:39 AM.