Question being this; unplugging the connector from the IAC I have 12V on one side and the other has no, ground. If I am understand this IAC's operation correctly I should have the 12 volts on my side of the connector and ground is controlled by the TPS.. correct?

So the two wire IAC connector unplugged from the motor car running I should have the 12volts on one side of the connector and I should have ground on the other at idle? I however have no ground on the one side.... TPS?

 

the IAC ground is controlled by the ECU.... when the ECU sees the idle switch is closed, then it monitors the engine RPM and pulses the IAC to maintain 600rpm idle (once warmed up. cold idle is more like 900rpm)

DTM #3 will test the IAC along with other engine actuators. see Engine and OBD Diagnostic Codes for the procedures...