Help diagnosing e20 on AEG Favorit 55002 VI

[shuckc]

I have a 2 1/2 year old integrated AEG dishwasher (2yr warranty) that for the last week has been throwing up odd e20 “draining fault” indicator. Sometimes a cycle completes without a problem, other times the program gets stuck with the drain pump running.

I’ve checked a few things so far:
– pump: moved drain hose into the sink. When the machine is full of water and a new program is started, it properly chucks the water out quickly with a good head of pressure, but then keeps on pumping (with a slight pause every 2 minutes) sometimes for a couple of hours before giving up.
– checked the trap and standpipe are clear
– cleaned all the filters and sump area as I do anyway

I read around that if the pump and drain are working, it can either be pressure switch or control board, or anti-flood.

I pulled out the machine and took a look at the base tray, pump and pressure switch. Seems not to be anti-flood as the tray is clear, float against the metal pan, and the machine can still be reset and start another cycle. It’s not the “always drain” you get with anti-flood. Pumps looks fine, runs OK and quietly, so don’t think blockage.

Pressure switch is a new style low-voltage sensor with +5V, 0V and a signal connection. Is marked as 7640 37640514 comes up as this one http://shop.ukwhitegoods.co.uk/40553477 … switch-kit for £23 quid.

There is a rubber hose from the sump to edge of the machine, then an inverted “U” bend, with the sensor below the assembly. I removed the rubber hose and brew towards the sump and it bubbled away clear, so that doesn’t seem to be blocked. I’m handy with a multimeter, but don’t know what the expected voltage or resistance readings should be for full/empty levels. Seems like they did away with two separate simple on/off pressure switches with this model.

I wondered if anyone had any ideas or if I missed anything obvious. Would like to test the sensor before replacing it or the control board if anyone knows how?

Thanks,
Chris

[Martin]

Re: Help diagnosing e20 on AEG Favorit 55002 VI

shuckc wrote:Would like to test the sensor before replacing it or the control board if anyone knows how?

Good luck with testing the analogue pressure switch. The manual states a frequency reading of 44.5Hz with 0mm and 36Hz with 300mm of water (full).

There are lots of variants of Fav55002’s by the way. To be sure of which one you have the 11 digit PNc number would be best to have. 😉

[shuckc]

Re: Help diagnosing e20 on AEG Favorit 55002 VI

Thanks martin, I’ve got a frequency counter on the meter so I’ll give this a go and see if its in spec.

[shuckc]

Re: Help diagnosing e20 on AEG Favorit 55002 VI

Hi Martin,
I wondered if you are still around? I was never able to reproduce the fault code whilst I had the machine pulled out last year. It’s taken a full 12 months to go from intermittent (1 cycle in ~20 failing) to failing every cycle.

I’ve stripped the machine side and front and taken another look at it. From the identity tag the PNC is 911436014/02 for Model F55002VI0P.

I chased the 3-wire loom from the fill pressure sensor back to the control board. I probed the sense wire against 0v and got readings of 35hz when full and around 51~53Hz when drained. Seems high when drained, so I wondered if you can check values for this pnc?

I did a visual inspection of the control board, nothing obvious. I then disabled the pressure sensor, all looks fine internally. The spring is free to move the ferrite core into/out of the inductor coil as the diaphragm moves (interesting design).

After reassembling it was the same, I couldn’t get the control board to accept the machine has emptied, despite the sump dry. I did an experiment by disconnecting the sense pipe to the sensor, so it was just reading atmospheric. This allowed the program to continue and start filling. It then got near to overflowing as no feedback so I turned it off.

Anyway, I’m short on ideas. I’m guessing sensor replacement, although it seems to be able to register atmospheric OK. It did occur to me it could be a problem with the sump moulding or sense tube or similar.

Is there a way to get actual diagnostics/readings out of the control board?

Anyway the wife threatens to throw either the dishwasher or me out next week, so I’d better come up with a plan.

[shuckc]

Re: Help diagnosing e20 on AEG Favorit 55002 VI

I have just seen on a few other posts that there is all manner of gadgetry behind the LHS panel, so I’ll take a quick look under there and see if anything obvious (impeller jug, blocked matrix, manifold etc).

[shuckc]

Re: Help diagnosing e20 on AEG Favorit 55002 VI

I took a look at the LHS, the manifold/matrix all looks pretty clean, even in the area subject to washback from the inside. I tried a rinse, and it got straight through. Now on a wash, seems to be working again. Very annoying 🙁

Based on disassembling the sensor and reinstalling it has helped twice now (and there doesn’t seem to be any metering/impeller jug on the inlet any-more) I will order up a replacement. Can anyone help with the part number needed to order it?

[yingwee]

Re: Help diagnosing e20 on AEG Favorit 55002 VI

I stumbled across your post as my dishwasher (Westinghouse WSF6605XR) was experiencing similar intermittent i20 errors. The manual also says drainage issues. The pressure sensor is identical to the one shown in your photographs.

The numbers written on the back of the part are
3002027511
117.474.522
[ I don’t think these actually helped with getting the part; the spare parts place had to hunt down the model and identify the part from the manual].

I replaced the part but am still experiencing the same intermittent i20 error. I turn off the machine and turn it back on again and the cycle continues, but the count down timer will increase in value again. For example, after resetting (power cycling), the count down timer will initially show 5 minutes remaining, the dishwasher will continue the cycle and then will display 15 minutes remaining. The cycle will finish eventually. If I use the ‘heavy’ cycle which is normally 143 minutes long and the i20 error occurs say with only 15 minutes remaining, it might restart at 50 minutes…

I don’t have a solution yet as the error is still occurring after replacing the pressure sensor.

[shuckc]

Re: Help diagnosing e20 on AEG Favorit 55002 VI

I bought the new sensor (substitute model is now blue) and it made no difference, still have a problem every other week or so maybe 10{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} of runs.

I found some wiring manuals on a spare parts forum, so next I tapped the wiring harness at the control board and hooked up a logic probe to the +5V, 0V and signal pins from the sensor. What I found is that usually the signal is a nice 50{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} duty waveform with frequency depending on fill level when dishwasher is working, and on some runs sense drops to 0V even through the sensor is still powered, which is when it gets stuck pumping out.

I think it must be an intermittent break in the wires from control board to the sensor, probably where it goes through the door parts and is flexed. When I next get some time I’m going to pull out the wiring harness for port-E on the controller to the sensor and check it over…

[monteman]

Re: Help diagnosing e20 on AEG Favorit 55002 VI

A most helpful thread; certainly the fault is very similar to that plaguing my 2012 Westinghouse WSU6603XR (and many other Australian users it appears) which uses the same pressure sensor. Otherwise an excellent machine.

Did anyone confirm that a break in the wiring from the sensor to the control board at the door hinge point is the probable culprit? It certainly makes sense as local failures seem to occur in years 3 and 4.

[suedehead1]

Re: Help diagnosing e20 on AEG Favorit 55002 VI

Hi I decided to jump on an existing thread.
I was at the exact same dishwasher model and pnc the same.
the dishwasher overfills then the pump kicks in then it overfills again and so on.
The customer fitted a new pressure switch from AEG but its still the same.
I couldnt get any assurances from the customer that he hadnt blown down the new pressure switch.

no blockages or water in the base.

any ideas welcomed

[Author]

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