Hello people. By coincidence destroyed my computer on the Fiat Seicento 1.1 (2002).
Type computer is IAW 59F M5 (HW305). I can not find here in Bosnia this computer.
What are the appropriate model for Seicento,
if you can be a little help to tell me what computers are compatible.
I found of the Fiat Punto IAW 59F M2 (HW002) if he would fit in Seicento?

IAW 59F M5???? Confused!.....I thought it should be a M1 or a M7- maybe i'm wrong. Is the ECU & code reader the original ones? & is it the original engine?

The ECU you need to fit will be one that speaks the same computer language as the code reader. For example you can't fit a IAW 59F M3 into a car that had a M1, they are not compatible.
Whichever ECU you get it is easier to get one that is described as 'virginised' or 'plug & play' that way you don't need to change the door locks etc. There are plenty for sale on eBay
Read this & it will explain about fiat ECU's-
http://www.cento-world.de/iaw-59f-und-5af-steuergeraete-faq-mpi-infos-und-reparatur-t22844.html

I do not know whether the original engine ECU and what he's done here but I know that the car works perfectly with this ecu. Does this mean that I have to get exactly the computer that is in the car? Can you recommend a reliable on ebay to order IAW 59F M5 (HW-305), as though this was in the car then it is safest to get the same..

The M5 version may be specific to some Countries with reference to the software on it. You can fit any MF59 Ecu that has been (unlocked) and remove the remobiliser as you won't need it. Or, get a virginised one with exactly the same M and HW number as quoted earlier.
Another option is a complete lockset, ignition, fuel filler cap, keys, Ecu and code reader from another car.

Does this mean that it can be installed IAW 59F M2 (HW002) but that it should be removed immobilizer? In what way can be attached to remove the immobilizer? Please be a little more explanation because I was already in some of the best car electrician in the city and failed to remove immobilizer attempt to insert IAW 59F M2 (HW002). That computer is unlocked but electrician can,t remove imobilizer. Explain to me how to remove the immobilizer that we could say electrician in any way it can be done.

Tomorrow should arrive: ECU (IAW 59F M5 (HW-002) and immobilizer code box and other key. The man from whom I bought says that all I need is to replace the ECU box code immobilizer and a new key to paste somewhere near the lock to recognize him immobilizer and I might as well use the old key to start the car.
I have two old key and so should be able to continue to use them. Can I insert somewhere in plastic inside the wheel of this new key to be invisible?

M2 ECU.... As far as i understand it the HW is the processor and memory type -it needs to be the same for the ECU & code reader so they can communicate. So a (more modern) HW305 code box cannot understand an unlock signal from a IAW 59F.M2 (HW002) ECU. The code box, it's connectors, & the loom are also different so you can't just plug in a different system.
This shows the M2 type of code box
http://www.ebay.co.uk/itm/1999-2006-fiat-punto-mk2-1-2-8v-ECU-KEY-LOCK-SET-IGNITION-KEY-BARREL-IAW-59F-M2-/131428006740?pt=LH_DefaultDomain_3&fits=Car+Make%3AFiat&hash=item1e99b83b54
This shows the standard Seicento M1/M7 code box
http://www.ebay.co.uk/itm/FIAT-SEICENTO-1-1-MPi-LOCK-SET-ECU-IMMOBILISER-2002-/261841838402?pt=LH_DefaultDomain_3&hash=item3cf6fd6142
I don't know what code box & wiring loom you have in your car.

IF you can use the ECU/code box that you bought you could just tape one of your old keys inside the steering column cover but that will mean the car isn't immobilised.... or you could CAREFULLY cut out the transponder chip from the new key.

& stick the transponder in one of these
http://www.ebay.co.uk/itm/Fiat-Stilo-Punto-Seicento-1-button-Remote-Key-Fob-case-/180715360370?pt=LH_DefaultDomain_3&hash=item2a13799072
You could get new keys cut but they will need the transponder coding. Someone like this might be able to help
http://www.ebay.co.uk/itm/Fiat-Transponder-Key-Cut-to-Code-Photo-ID48-CODE-2-Punto-Seicento-Multipla-/131275699634?pt=LH_DefaultDomain_3&hash=item1e90a435b2

Have you bought a new pair of ignition coils? Often when the ECU goes wrong it damages the coils, they're not very expensive (& might save you damaging the replacement ECU).

Thanks to all. The problem is solved with ECU (IAW 59F M5 (HW-002) and immobilizer code box and other key. I move key reader ring on another place from lock and took a chip from the new key in key reader ring. It is not important to me immobilizer. The important thing is that it works and that of the old and new key codes are not confused when I want to start the car. Now normally use my old keys when I open the car and when start the engine and the important thing for me is that