Error code confusion :/

[304runner]

Just wondering why Im getting an error code 12 (system check ok) then it spits out error codes 35, 36, 45, 46 ?

Im aware I need to fix the other faults but is error code 12 only popping up when the check has started and finished?

[Error Codes] >>>> Just Commodores - For All Your Holden Commodore Needs

[accentstencil]

Because it always starts and finishes with code 12, regardless of whether there are fault codes or not.

[304runner]

Ok cheers, thought that was the case...