Empowering Drivers P0505 - The Ultimate Guide to Idle Air Control System Troubleshooting

The whole point of an idle air control valve is to regulate the air coming through that bypass channel. If they are plugging it and it is going ... That is an open or short code for the IAC since you had your engine replaced simply check if it is plugged in. Rodent nest in the air intake . You get the PO505 when a different idle pattern is detected it can be any place in the whole circuit . I keep getting the p0505 code. Everything seems fine, runs smoothly, idles fine. I have been searching for intake vac leaks, but no luck. Any ideas anyone? My car has been acting goofy, and just the other day it spit out the P0505 code (which usually means bad IAC, but I'm looking for some expert advice). P0505 can be caused by not only a bad IACV but also a vacuum leak, misadjusted idle speed, bad ECT sensor/circuit, or bad TPS sensor/circuit. The P0505 code can be caused by a faulty idle air control valve, vacuum leak, damaged wires or connectors, an idle speed that isn't calibrated, ... 1st- I believe the IACV is shorting due to it overheating. Both bad IACV's showed no signs of deterioration in the coolant channels, just bad impedance ... The IACV valve is operated by a step motor. This motor has winding phases and is actuated by the output signals of ECM. 2004 Toyota Matrix XR with only 111000 miles.