The integrated unit is under the dash, just to the left of the steering column, but not on an '02. There is definitely no integrated unit on any '02 Impreza, or any '02 Subaru that I know of. Drive by wire=body integrated module. Are you looking for the immobiliser module? It is directly under the steering column, small black box, white connector, i think 8 pin

__________________
Its just the internet dude, its not real.
F.B. Racing
01 WRX (STI badged)
2010 XR5 Focus
06 Impreza Hatch 2.0i