GB2125

I’ve also checked all the fuses and none have blown

I replaced the battery with a new one and the fault is still coming back

Hi all, My car recently had trouble starting and was sputtering to a start when it did start, I checked the battery and alternator, both were good but i change the battery anyway to be safe. there's been about 30 fault codes coming up, most are communication BUS errors but 2 stuck out; terminal 15 short to circuit and terminal 30 open circuit. Both are labelled Voltage Supply being 30A and 80A respectively. I'm leaning towards a faulty ground connection but any help with diagnosing the issue would be appreciated.