I'm dealing with a P0505 on my 2000. I've replaced the IACV, re-learned, cleared memory, checked the TPS, checked voltage here and there, jumping jacks, etc (followed the ESM diagnostic procedures for P0505), to no avail. Still P0505. This is just lovely.

I did notice my resistance values for the brand new IACV was about 12 ohms for one test and 12.4 for the second test. The ESM demonstrates two tests you should perform. Their comment is "about 22" should be the value. I never performed the test right out of the box. I only did so after I replaced the IACV and was still encountering the problem. As a side note, I check resistance on my old IACV and both tests were about 12.0 each.

If you have done this test, were both of your tests individually "about 22" or am I supposed to combine the value of both tests to get "about 22"? If each test should register 22 then I have a falty IACV but if I combine then everything is good. I have a hard time accepting the new IACV is only half up to par.

One other thing: the car will stall unless I leave the throttle opener hose unplugged. This does not seem to be the case on cold starts...meaning all hoses can be plugged in until the car warms up...then it dies. Car runs great with the hose unplugged and will run great all day long. The "check engine light" stays on and is lonely. I clear it and it comes back on.

Thoughts on those resistance values?

 

By my experience... your ECU is fried!!

 

Did the dealer indicate the ECU was the issue or did you perform some other test to come to that conclusion?

 

My Max would stall... changed the IACV, did all the procedures (re-learn, etc...) and car would idle @ 1500-1700 rpm and P0505 code will still be there and CEL would be on.

Brought to the dealer, they plugged to the Consult and told me my ECU was fried... replaced the ECU (new) and problem fixed.

That's my experience;

Peter