Fault codes
 

Hi everyone, i put a dual battery set up with battery box and a relay in my 2012 iload, just wondering does anybody know if hyundai made the system that doesn't like a foreign current or has an answer for me? I tookit to a shop,the fault codes say the fuel pressure is low and the fuel rail pressure is high, we disconnected the 2nd battery set up and it didn't happen, reconnected it and it's happened again,have disconnected again and cleared the fault codes. If it doesn't happen again i guess i have my answer.

There is an old expression among mechanics. It goes something like , if after replacing the starter with 3 different starters, it ain't the starter.

Would appreciate, if you get to the bottom of the problem, just what you did to correct the problem, can you do this, thanks.