I wrote the following as a general article but it should give you some good info.
I have got set up with MultiECUScan. I decided to pay for the full version as I read that the time limited version did not support the Ph1 3 pin system.
The first step is to buy the right leads. The Ph1 Gtv uses OBD1. (On Board Diagnostics version 1) This means the diagnostic sockets on the car are a 3 pin arrangement as oppose to the more modern 16 pin OBD2 version. You can buy these leads cheaply on Ebay, search Fiat or Alfa diagnostics leads, they have the 3 pin plug one end, black and red crocodile clip leads and a 16 pin socket on the other end The black and red crocodile leads are there because the system requires a permanent 12v supply
The second lead you need is a standard VagCom KKL OBD2 lead. This has the 16 pin plug on one end and a USB plug at the other. Note, you can buy VagCom KKL OBD2 leads with different switching dip switches in them. This is not needed in our case, just a standard lead.
To make life easier picking up the permanent 12v supply to the crocodile clips, I also brought a cigarette socket plug and made a lead long enough to reach the cigarette socket (which is permanently live on the Ph1 Gtv) to under the bonnet for when you need to look at the ABS ecu.
Once we have our leads, it's time to down load the software. This is very straight forward, go to www.Fiatecuscan.net
and follow the download instructions. Note, you will need to purchase the registered version at a cost of €50, it will not work on the Ph1 with the free version.
So now we have our leads and our software, next we have to download our drivers to the laptop to make the leads work with the software. The OBD2 lead should have come with a small CD, this contains the drivers. When you plug the USB end of the OBD2 lead into the laptop for the first time, you will see the computer attempting to locate drivers; you may have seen this before if you have ever used a USB memory stick. Once the computer has failed to locate the drivers, a window will pop up asking if you wish to locate them yourself. You then use the 'browse' function to direct it to your CD drive where the drivers disc is loaded. You may need to do this a couple of times to get all the drivers you require but you will know when you are done because you should get a message telling you your drivers are up to date.
Once the drivers have been loaded, you can now go to device manager via control panel on the laptop. Make sure the USB lead us still plugged in and look for the USB serial port settings, highlight, and right click the mouse. Go to advanced settings and check what com port number is now being used. Mine was Com port 4 but I think it could be any number. You also need to set the 'latency timer' number to zero. We are now ready to try the diagnostics on the car
With the ignition off, join the leads together and plug them into the ecu socket you wish to look at. Plug in the 12v plug and connect to the red and black crocodile clips. You will know the 12v supply is present because the VagCom lead usually has an LED on the 16 pin plug that lights up with the 12v. Now launch FiatEcuScan. Go to settings on the bottom left corner of the home page, open the interfaces tab and check the interface type is correct, K-line/VAGCOM, and the coms port number is the same as the number we found in device manager. Both these settings can easily be changed using the drop down menus if need be
Once you are happy the settings are correct, it's time to connect to the car. Switch the ignition to 'MAR' position. Now locate your vehicle from the list and select. Now select the ecu version that applies to your car and connect. If you don't know your ecu version don't worry just select one from the options given and try to connect. You will be asked if you wish to connect to the 3 pin adaptor, click 'Y'. If you do select the wrong one, you will just get an 'Invalid ISO Code' message and you can try a different version. Mine was - Alfa > Gtv 2.0 TS 16v > Bosch M2.10.4
You will know when you have successfully connected and you can play to your hearts content! If you want 'live' data, simply start the car. It looks like a very good set up, I wanted to get set up to find out what kept putting the engine management light up on the dash of my car but reading and clearing fault codes is just a small part of what can be done. There are lots of real time data and you can set up graphs as well as test some operations, for example the radiator fans
I particularly like the fact you can force the ABS ecu to 'fire' thus you should be able to bleed the air out of the ABS pump if need be, something a home mechanic has dreaded in the past. A good friend of mine has a constant ABS fault up so hopefully we will now be able to sort that out.
All in all, well worth the £60 or so setting up costs. It's not as hard as it might sound and I recommend you give it a try, especially if the threatened MOT failure for an active engine management lights comes into place!