I have a 2000 Si that threw a check engine light. I had it scanned at Advanced Auto and it came back P0505, idle control system malfunction. does anyone happen to know anything about what causes this or how to fix it, or atleast to direct me somewhere that can help? Thanks.

 

What symptons are you getting? Erractic idle? High idle? Low idle?

 

IACV (idle air control valve) is dirty/malfunctioning/broken.

It is located on the back of the intake manifold. It has 2 coolant hoses going to it and I believe two bolts to remove it.

I had the same exact thing happen to me on my 99 Si. Unbolt it and clean it out real good. I used throttle body cleaner and sprayed the hell out of the screen in there and let it soak. Try to get it spotless. Put it back on and reset the code. Hope that what you did fixes it because if not is about $189 to replace it. On mine a cleaning made it go away and I havent had a problem since (knock on wood).

Hope that helps!

 

Happened once to me. It turned out to be the vacuum line from the cruise control to the back of the intake manifold was unhooked.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bebfsu1 &raquo;</TD></TR><TR><TD CLASS="quote">Happened once to me. It turned out to be the vacuum line from the cruise control to the back of the intake manifold was unhooked.</TD></TR></TABLE>

that could cause really bad idle. any other tips?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bebfsu1 &raquo;</TD></TR><TR><TD CLASS="quote">Happened once to me. It turned out to be the vacuum line from the cruise control to the back of the intake manifold was unhooked.</TD></TR></TABLE>

wow dead on the money. lol i totally forgot the lower vacuum hose for the cruise control. the strange thing is, this is the first time in like 2 days after firing up the car as obd2 (for smog) that it threw the code. anyway thanks to the search function and this new obd2 scantool, i was able to reset the ecu and use my 15 minute test drive route to verify that set 3 of the 4 readiness monitors are set. just gotta wait 8 hours and set the Evap monitor in the morning and try to pass smog.



Modified by ( o )( o ) at 10:03 PM 5/5/2006

 

Question: I am seeing P0505 code being thrown in civic 99 Ex, really bad idle, bucking when giving gas and overall terrible accerlation. I noticed today that my cruise control is not working. Can this be related? All this started after I got my front driver side brake line replaced since it was fractured due to old car frame (another long story)?

To be specific, it not like the cruise doesn't engage, but it after engage it does't hold even though cruise light is ON. It like a balloon losing air.