Got a jeep 4.0 petrol 2002, with 4 wire iac valve which is not operating, and sets a code p1505 every time after an ignition and start stop cycle, ive included a capture, and i am looking for someone to explain whats happening in the trace, good or bad.
during this capture the idle remains at a very steady 2200 rpm but ocassionally fluctuatting slightly by a couple of hundred rpm
some info on AD Kenny, but i'm not 100% on which model of Jeep you're working on ??
If it's 4X wire i would expect the IAC to be driven in opposite directions (in/out) by 1 pair.
You could also volt drop it from PCM -IAC with a math channel, but maybe something will show up on the current first ??
When you ask about clamping 2X wires with the current probe do you mean 1X from each side of the IAC ? if so i don't see why not as a problem would show up better on 1X screen/capture rather than 2X.
I should imagine the voltage stated is the 'average' voltage as measured with a DMM because it is NBV on the other side & will be until grounded by the PCM, but when i looked at the pin out data on AD the waveform looks different !
Measure the resistance with a DMM on each side & to the body of the IAC. Also if you can find a resistor X2 the same resistance or a consumer X2 on each side of the connector & see if the DTC goes ?