ABS diagnostic codes with standalone engine management

[MX4]

Hi all,
I have the ABS light showing on my dash indicating an ABS system issue. I tried to read the codes from the ABS diagnostic port but it is giving a solid signal (ie - its not flashing). It should always flash evening if the ABS system is functioning correctly. My only guess is that because I have installed an aftermarket engine computer it is causing issues with the ABS system being able to give a diagnosis. I have checked www.vfaq.com for the factory engine ECU pinout and it shows that there is a wire connected between the engine ECU and the ABS system. Does anyone know what importance this wire plays?

Thanks all.

Ryan