My Bosch dishwasher was broken recently. It kept running for hours. Here is how I fixed it:
First, the symptoms: The dishwasher would run for a long time... hours. It didn't really get things clean. When the door opened the inside was not warm.
The first step was running the built-in diagnostics. To do this press the Power Scrub and Regular Wash buttons at the same time, then press the power button. One of the lights will show up.
If the WASH light shows, that indicates a heating fault
If the RINSE/DRY light shows, that indicates a filling fault
If the CLEAN light shows, that indicates a NTC (Temperature Sensor) fault.
Mine showed WASH so there was a heating fault. When this shows it can be a problem with the heating element or the electronics.
One of the common problems with this dishwasher is that the solder joint for the heating circuit can burn out. It is pretty simple to fix if you have a soldering iron and a torx screwdriver (#20 size). The circuit board should be checked before replacing the heating element because it is faster and easier to check and repair.
Step 1 is to unplug the dishwasher. Even though the wires to the power switch are insulated, it is always a good idea to make sure there is no power going to the dishwasher.
Step 2 is to remove the Fascia - the front part of the dishwasher with the buttons on it. To do this you use a torx #20 screwdriver. Open the door and remove the screws from along the top edge of the door. Remove the two screws from the side which hold the control panel in place. I also remove the two screws at the top of the front panel to make it easier to get the control panel in and out.
Once the screws are removed, the control panel can be pulled up and forward to free it from the door.
Once this is done, disconnect the wires holding it in place. First the connectors to the control module:
Then the connectors to the Power Switch and the Ground Wire:
When these are disconnected, you can remove the panel entirely and set it on a soft surface. It is possible to skip disconnecting the wires, but it requires juggling a half-open door and a wobbly control panel while you try to unclip the control module.
The next step is to unclip the control module. There are plastic clips at both sides that need to be opened and then the module rotates free with a hinge at the upper side:
Unclip by sliding a flat screwdriver or other tool under. Do not bend too far or you risk breaking off the clip.
Swing the top up so you can get to the next set of clips which hold the circuit board in position. These are similar to the first set, but smaller. You can use your fingers to release them.
Once those clips are open, you can pull the circuit board up to see the back side.
Once it is visible, look for a burned solder joint near the middle of the board as shown in the photos. It will look something like this:
Clean the joint with an x-acto knife or whatever else you can use. Then get out the soldering iron and resolder the joint. Put it back together in the reverse order you took it apart. Don't forget to plug it back in!
Test by running a wash cycle. If the heater comes on and the wash cycle is back to normal times (about 90 minutes) then you have fixed it.
If you can't succeed in repairing it, the whole module is typically available for about $150