Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
I have 06' commander with 4.7 and i keep getting a po507 code! I have smoked the system and repaired all vacuum leaks i can find!! Checked the air box, filter, hose connection and all seems fine. Aic is operating as it should, snap on Verus pro shows 0 % aic at idle and it will only control the idle test down to 900 rpm ! I watched your video on this issues and you said most always a vacuum leak, but you then saidit could be other things as well, please say what the other thing may be!! Thanks, great Fan of your work!!!! Bob in Il.
IAC command to zero and still having high idle typically is from a vacuum leak.
I know you said the scan tool test won't drop idle below 900rpm, where does the engine idle once it's warmed up?
Is there data PIDs to compare actual rpm vs desired rpm?
Some things that come to mind are a sticking IAC valve not actually closing all the way, naturally a vacuum leak, possibly an EGR valve issue.
