• Please note, some of the links on our site are affiliate links (Learn More)
  • Important Announcement

    It's with sad news to announce that our site owner, Jake, has passed away. You can read the details here.

Bosch SHU5312UC/U12 Error message


Premium Member
Feb 9, 2005
, ,
Need help finding out what an error code means on this dishwasher. The only mode that works is the rinse /hold mode. All other modes when selected bring up 2H on the display. Already pulled the control board and repaired the relay solder joint. Checked the edge connectors. Does anyone know what that error message means?
imported post


I haven't had to work on many Bosch Dishwashers.

Jeff1 , Dan O. or Mad Mac may know more on the codes.

imported post


Isn't 2H - 2 Hours? Possible delay start is set.

It might reset lower on it's own now that the ?heat is working? since you mended the board?

May take one or two cycles as the times alloted for each cycle can change on there own.

Most fault codes are an "F" code....a copy:

-- NOTE: An "F" fault code in the display for SHU/I 53/68 dishwashers shows there's a filling problem (not filling, overfilling, underfilling or water in the base). The fault code can't be reset manually – it will reset itself 15 minutes after the dishwasher has been turned on (after testing how it fills). -- -

A copy:

To start test program, press and hold both SCRUB WASH and DELICATE/ECONO program buttons, then turn unit on by pressing ON/OFF button. Initially, control module version # will be displayed (e.g./ “21� = version 1 with jumper). When wash program buttons are released, lights above them will flash. To end test program, press ON/OFF button. To check each program indicator light, press its button. To check Cycle Countdown display, Refill Rinse Agent light and
REGULAR WASH light, press REGULAR WASH button (press Delay Start button to test Cycle Countdown display alone). Cycle Countdown display will show "88" when REGULAR WASH button is pressed and "8h" when Delay Start button is pressed.
To start testing, press both the
SCRUB WASH and DELICATE/ECONO buttons a second time. When testing has ended,
Cycle Countdown display will show a fault using codes below. If more than one fault occurs, code numbers will be added together, (e.g./ “6� = faults 2 + 4).
0 = No faults detected 2 = Heating fault 8 = NTC (temperature sensor) fault
1 = Aqua Sensor ("Sensotronic") fault 4 = Filling fault F = Filling fault (display occurs during wash, not test)
To check for heater, high limit or flow switch problems, start testing until heating starts. Using a meter with a current coil, measure current going into dishwasher. If current is ~ 11 A, then heater, high limit and flow switch are OK. If current stays at ~ 1.5-2 A, then heater, high limit or flow switch are faulty.
If water level switch (
f1) has failed (opened), display will show fault code "4" and unit will continually fill and drain where testing won't be completed. If flow switch (e5) has failed (opened), display will show "0", water won't heat (to 150ºF) and water wont stop circulating. If NTC probe (f2/f4) has failed (opened), display will show fault code "8" immediately and testing will end shortly after water has started circulating.
Hope something is this jibber/jabber helps.
imported post


Thanks for the reply, the display on this unit for the delay start uses a small case h, this indication is a 2H, I've done the system reset which gives a CL , I'll try the other tests that you have mentioned. Thanks again.

imported post


Went home and ran the tests that you sent the procedures for. Everything checked out except the test cycle ended with a 1 in the display. According to the information you sent this means the "aqua sensor" (sensotronic) is bad. I have no idea what this could be unless it is a flow switch of some sort or a float switch. Will have to tear into it again this weekend. If you happen to know what this device is letme know. I work 2nd shift and weill be here until 11 P.M. EST. Thanks again for the info.

imported post

A copy:
Aqua sensor
(SHU 53-- & 68—only)
Find three brown wires at far right of control module. Measure resistance between middle wire and left (preferred) or right wire (+-1 M ohm).
HINT: Don't check this unless customer has brought up long wash times (and has measured them). The sensor checks water clarity and adds a wash/rinse cycle only when the rinse water is still dirty.
HINT: Due to nature of sensor, resistance readings can be inconsistent. HINT: Must pull out dishwasher and remove left side panel to access sensor (for measuring or replacing). Sensor can be pulled out of sensor assembly at rear of sump.
**Everything checked out except the test cycle ended with a 1 in the display**
Have had to change a few controls for that problem.
Hope something here helps,
imported post


When you say you've had to change a few controls ,is that the whole control board or the sensor? Also if the resistance reads O.K. does that mean the board is bad? As you can probably tell I have troubleshot and repaired different machines before but this is my first dishwasher and it's a little tougher without schematics or a tech manual. Thanks for all the help.
imported post

**When you say you've had to change a few controls ,is that the whole control board or the sensor?**

Whole control board yes.

Sensors, none yet.

**Also if the resistance reads O.K. does that mean the board is bad?**

I'd suspect that. The board -usually- has a 5 year warranty.

**it's a little tougher without schematics **

Usually a wire diagram ( not a great version like we use here ) is normally tucked away underneath.

**or a tech manual**

Email me...maybe title "Bosch dishwasher"


imported post


Sent you the E-Mail, thanks for this help, my first time on a Blog or message board or whatever you call this. it's really been a good experience. heading home for the weekend and do a little more troubleshooting.


Users who are viewing this thread

Support Our Site

If you feel that you have benefited from this site, and would like to show your appreciation, please consider making a donation.