I've read elsewhere that connecting TAT & GND is required, but you can then read the code from the flashing of the Hold Light, and no need to put an LED connection across B+ & FAT pins. Is this correct?

All looks good, I'll give it a try. Only thing is what's the led mentioned? Is this on the vehicle, or one I've to put together on wire connection?

I'm looking at a local Bongo, 1997 2.5D Automatic 4WD. It seems to drive fine and not being restricted to 'Limp Mode' however the Hold Light is flashing. As its not in limp mode can I assume that this is maybe an electrical connection fault? I believe it might also be a fault with the device fitted ...