No signal from PCM to IAC

[fordgirl]

I went to test/clean IAC and got 0.015V when I probed wires of the terminals of BPA-ISC. I should get 10.5V. Any other wires I could probe easily to see if my PCM is failing?

 

[fordgirl]

So I went to recheck the voltage...When I connect the positive probe to the red wire I get 0.05V and when I connect the negative probe to the other wire (of the electrical hook-up to the IAC valve) it drops even lower (~0.02V). If this means anything, when I ground the negative probe to the battery I get ~12V. Makes me think I have a short in the wiring from PCM to IAC?? I don't know a lot about circuits or electricity, but I am trying.

 

[blacksnapon]

Different voltages for different situations

IAC 21 VBAT DCV 7.0-10.2(hot idle) 5.6-8.5(30 mph) 2.0-6.8(55 mph) DCV

 

[fordgirl]

So sounds like the Haynes manual is wrong. It says around 10.5V for KOEO.

I will see if I can get 7-10.2V at a hot idle.

I am also going to use this website adapted for 2 connectors (I am assuming I do not have a ground in this case..?)
http://www.justanswer.com/volvo/2f4ka-check-idle-air-control-valve-bad.html#re.v/173/

Also, I will unplug the eletrical harness while truck is running to make sure idle goes high and IAC is actually doing something.

I will post results, thanks!

 

[fordgirl]

Results are in and I am confused! Following that website link above i got the same battery voltages from both pins of the electric harness to ground (separately). Resistance on valve checked out. That link is made for a 3 pin, so should i still get the same results (6-8V for one)???

Hot idle was only at 3V between electrical pins that i backprobed while connected to valve.

When i disconnected electric harness while running the idle barely changed but did go lower and definitely ramped up when connected.

Do i have a problem? Im chasing a PIP circuit failure and just checking electrical things nearby.