Unlocking P0505 Essential Knowledge for Idle Air Control System Diagnostics

The IACV valve is operated by a step motor. This motor has winding phases and is actuated by the output signals of ECM. The P0505 code means there is a short in the IAC valve circuit. I replaced the valve, check the wiring and old valve - both where ok. I'm ... 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 ... That is an open or short code for the IAC since you had your engine replaced simply check if it is plugged in. Detailed information on troubleshooting and repairing a P0505 DTC code which refers to a malfunction of the IAC (Idle Air Control) system. The code P0505 stands for “Idle Control System Malfunction,” which means that the powertrain control module (PCM) can't control the idle speed. Take the Idle Air Control valve off the bottom of the Throttle Body and clean it. If that doesnt work you may need a new one. 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). The code sets when it can't get the idle speed within +200 / -100 of the target for more than x seconds, and it takes a failure in two successive drive cycles ... A P0505 is an Idle Air Control issue, it has nothing to do with the PCM. The IAC is what provides and controls all of the engine's air when the ...