KIA SEDONA odd DTC? help!

Hi All.
I have a 4 year old KIA Sedona with the merc common rail turbo diesel engine. The engine is dead at moment with mechanics scratching their heads.
The code produced by the ECU is "U1DD8 NOT DEFINED CODE".
The garage have diagnosed a faulty ECU and recommend it replaced, but they can't tell me what the code means exactly. Can you guy's help with this, before I shell out best part of £1000.

what mechanics? What's the dealer say?

A "mechanic" is the term for the guy working on the car, its a UK thing.

The car has been looked at by the main uk KIA dealer from the start , so the above info of my first post is the info they, the main dealers, have given me.
That is, the kia main agents have plugged in an approved "KIA" diagnostic tool and the code read off was as I quoted "U1BB8".
They (the main dealers) say it is not listed in their "Kia" official diagnostic code book, so they contacted Kia head office to find out what this code ment, they were told the code means I need a new ECU !! but they cant tell me why. No one has been able to tell me anymore about this damn code!

......Further to this kia told me today that they had tried injecting diesel direct into the common rail under pressure, and when the engine was cranked it started and ran normally, if only for a short time, indicating no problem with injector firing, or air sensors, cam shaft, belt etc etc which is good news, and, apparently showing that the ECU is capable of running the engine!!??!! now i'm really confused.

But, and its a big but, they think all this points towards a further problem with the injector pump itself, and its associated plumbing. They think the pump may have disintegrated, causing fuel line contamination with metal filings, a common problem apparently!!

..... So at another £3,000 uk pounds to have the whole fuel system ie pipes, tank, injectors, pump etc replaced oh not to mention the ECU that they think caused it all in the first place at £1,000.

Total £4.000 and I should have a working car again in about two to three weeks..... maybe.

...... Anyone want to buy a low milage rolling chassis

And Just to clarify ..... There was a typing error in my first post on the fault code. The correct code given to me by kia is "U1BB8" not "U1DD8" sorry about that.