Hotpoint DWM55 Error - Flashing Lights Eco and Fast?

My dishwasher recently gave me the flashing lights as described in the Title of this thread. I contacted Hotpoint to ask what this was and they responded with

“Thank you for your email.

Those lights flashing are error code AL03 we would suggest that you
visit our website using the following direct link to find a selection of
error codes listed:

http://www.hotpointservice.co.uk/hs/pages/content.do?keys=FAQ:ERROR_CODES
“

AL03 refers to “Short circuit on thermistor or Time-out drain - Check filter for blockages”

So decided to take my dishwasher apart and have a look for myself. Immediately on removal I noticed that there had been some leakage which appeared to be from the waster pipe because it had been caught at the back of the machine and hadmade a small hole.
When I took of the bottom plate that covers the mechanics I found it to be corroded due to persistent water damage (plus the water pump driver motor housing was also water partly sitting in the water!). Still, it never caused the Float to rise and trigger a “water sump fill problem”.
I have read a lot of information on the net that basically points at the problem being due to a Filter blockage of sorts. So I dis-assembled the waste pump, checked for blockages in both the pump and the piping. I re-assembled the pump and re-connected to the system. I re-stood the dishwasher back upright again and this is what happened ( in sequence ):

1) With the DW powered up I select “normal” wash and hit the “start” button. The “normal” light goes out and no lights are lit
2) The water from the mains is now allowed to enter the system and fills the bottom of the dishwasher just to a level above the metal floor inside Also, the small reservoir on the left hand side of the dishwasher (near top ) also pre-fills to a level. ( **what is this for )
3) The water stops entering as I assume the mains water cut-off valve now closes
4) A ‘frothing’ / ‘bubbling’ noise is heard, and closer inspection shows that this is heated water ( with detergent I assume ) entering the plastic transparent pipe at the back of the unit to the top spray arm connector. It is not successful in forcing hot water into this outlet. No water appears to be arriving at the bottom spray arm either. Concerned for the heating block burning out because of lack of water I decide to power off the dishwasher
5) With the dishwasher reset I now restart the cycle to “normal” again. Upon pressing “start”, the indicators on the right of the unit (pre-wash,wash,rinse,drying) goes straight to “pre-wash” ( this I never recall happening )
6) IT remains in this start for several minutes ( unsure precisely how long ) and then the “eco” and “fast” indicators start to flash at a rate of 2 a second. The dishwasher is no locked up and only re-power for a minute of so will clear this error message.

At the moment I have only the water drive motor to consider as a potential candidate for this problem. It does show some was marking on the outside housing but yet I cannot confirm it has entered the motor itself. I need to test this. I would like to remove it from the dishwasher but I am having some problems. There are two locking screws that hold the metal Motor housing onto the plastic pump shaft. When undo these two I can see I have to twist the motor slightly to unlock two plastic locating pegs. Once done the motor is free but that drive head is stuck inside. A couple of questions that I hope someone can answer :

Can some confirm if I have to dismantle the pump shaft aswell to get the motor out?
Is fair to test the pump using a mains direct connection as it is correctly rated ?
Is it this pump that is meant to be forcing water through the heating element tube ( to the the upper outlet spray arm ) and the lower outlet spray arm?
The cycle jumps straight to “wash”. Would such a motor error cause this to happen?

I am sure I have more questions but would be good for “an expert” to help answer these and check if I am on right tracks. I really want to solve this myself, to save pennies and just for the sheer fun of it

Thanks,

Lee