The listed Model Number is incorrect I think it should be GSB5712BB1

Here is your parts breakdown
Model GSB5712BB1

Here is the operators manual and wiring diagram
ftp://ftp.electrolux-na.com/Pr.../Kinston/154429201en.pdf
ftp://ftp.electrolux-na.com/Pr...DF/Kinston/154444501.pdf

LO is low rinse aid
Can be a number of things:
1. Unit low on rinse aid
2. Sensing switch shot - looks like you would have to replace the dispenser
3. Bad connection between dispenser and control board -
Disconnect power.
Open it up
Clean the connectors.
Use electronics contact cleaner or isopropyl alcohol and a tooth brush. Be gentle and do not reconnect till all the solvent evaporates.
Clean the edge connector.
If it is the type where there is not a connector just the insulation is removed, it can be cleaned with a pencil eraser. Do not use an ink eraser as it is too abrasive.
Check the tracks in the ribbon cable for hairline cracks. A magnifying glass helps here.
Reconnect everything and give it a try
4. The control board is messed up - probably have to replace it

If it is the switch I would be tempted just to short across it and just remember to add rinse aid periodically.
NOTE: I am not sure if the switch is open or closed when rinse aid is full.