I went to switch my car from auto to fully locked diff and it wouldn't work. The ABS light has been on for about 1 month now so I'm assuming this is now connected ?? who knows where this fault can be fixed ?? car is a JDM 2003 STI

 

there is a diagnostic test that can be run but your better going to a dealer to get it done

 

do you have an OBD2 port Steve?

if so you could used my PSI3 to read fault codes?

 

none of those work with my autronics ecu