Trouble code P0505

GLP

MEMBER
2003 HONDA ODYSSEY
6 CYL
FWD
AUTOMATIC
168,000 MILES

My 03 odyssey has a trouble code P0505 - Idle Control System malfunction (no other trouble codes). I was going to replace the Idle Air Control valve but I would like to know if there is anything else I should try before doing that.

The symptoms are as follows: Idle fluctuates between 1000 and 1500 rpm when in park or neutral. Does not fluctuate when in drive or reverse. Also, idle fluctuation stops when I turn the steering wheel back and forth.

The problem started after I picked the car up from the body shop. They replaced the windshield and fixed the rear bumper. I don't know if they had anything to do with the problem, but that's when it started.

Thanks for the help.

5 Replies

RASMATAZ

MECHANIC
75,992 POSTS

You can try cleaning out the idle air control valve and see what happens-

Technical Service Bulletins Information

Number Date Title SN040901 09/01/2004 Idle Fluctuation, DTC P0505 & P1129 Check IAC Valve

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Friday, January 7th, 2011 AT 6:21 AM

GLP

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29 POSTS

What will it look like if it needs to be cleaned? Also, what is the best way to clean it.

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Friday, January 7th, 2011 AT 6:45 PM

RASMATAZ

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75,992 POSTS

Use carb cleaner/decarbonizer and small bore brushes

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Friday, January 7th, 2011 AT 7:48 PM

GLP

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Replacing the IAC valve fixed the problem. I tried cleaning it but that didn't work, even though there was a build up of carbon deposits.

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Monday, January 10th, 2011 AT 1:51 AM

MIKE H R

MECHANIC
3,094 POSTS

Use some throttle body cleaner and do the whole thing from the air intake to the throttle body if there was as much carbon as you say there could be carbon at other places even one going to the IAC. When you use it let it sit for a minute before starting engine. Have to do it to my wifes car. Did not work the first time so I redid it again and it finally worked. Have found just a speck of carbon can make a car act funny.