P0505 Decoding the Throttle Position Sensor Enigma

The error code you received is for a faulty IAC valve but it probably is related to the idle speed that you fiddled with.... The ECM regulates ... I've replaced the IAC valve, thoroughly cleaned the throttle body and can't find any vacuum leaks. Idles very high and can't figure this out. P0505 is thrown when your idle air PWM cannot reach the desired RPM the ECU wants. I get this when controlling my idle with an aftermarket ECU ... P0505 - Idle Control System - OBD2 Trouble code: ✓ Meaning ✓ Causes ✓ Symptoms ✓ Diagnostics ✓ Repair guides ✓ Repair costs ➤ Keep your car healthy. LS - 1st and 2nd Gen (1990-2000) - P0505 Idle control malfunction - Got a CEL this weekend on my '98 LS. I pulled a P0505 code out of it ... How to fix a P0505 engine code: Idle Control System. A P0505 code is set when the computer detects the engine RPMs at Idle are erratic. The P0505 can be caused by a dirty or damaged throttle valve, loose or damaged PCV hose, or carpet obstruction causing the accelerator pedal to be slightly ... Code 0505: Check 1: With the engine idling at operating temperature, remove the electrical connector from the IAC valve. If the idle speed doesn ... 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.