02 impreza ecu in a 02 forester, help needed?

[SF5Fozzi]

Hello.

Ok, hoping someone can shed some light on an issue im having please.

Impreza ecu in a forester.

The issue is, everything works as it should, apart from one rather annoying difference in the wires(maybe). 

The fuel pump constantly primes on with the ignition on, just before the next turn to start it up.  

I put my forester ecu back in the forester just to confirm it turns off after 2seconds of priming. It does. 

I put the impreza ecu in an 02 impreza & all ok. As it should be. Fuel pump primes for 2 seconds then turns its self off. 

I put my forester ecu in the impreza, & guess what, the opposite happens, no priming at all ?????

Again everything else works as it should with the impreza ecu in the forester.

it just annoying, knowing that something's not quite correct. 

anyone know the 'fix' ?