P0505 - High Idle When Warm
04-30-2012, 10:27 AM
#1
P0505 - High Idle When Warm
I have had a P0505 (Air Idle Control System) for the past few days, which was not fixed with new IACV. Code is now gone (as of last night) but I still can't bring the idle down from 1000 - 1100 RPM. What gives? Symptoms have typically been largely normal idle when cold, and high idle at full operating temperature. Changing IACV did nothing.
From My readings, I guess it can be either the MAF, TPS or the power steering high pressure switch. Anyone know how tho test the switch?
Here's some background on the development of the problem:
About a week from last Saturday, I was driving a little more spirited than usual on the highway (about a one hour trip) and when I was close to home, SES light came on: P0505. I cleared the code. Since then though, I noticed the following:
- my idle would be a little high after the car is at full operating temperature (1000 - 1100 RPM; it had done it occassionally in the past, but kind of seldom, so I never gave it much thought).
- Also, the transmission seems to occasionally have displaced shift points (delayed O/D on hard acceleration & delayed shifts - especially from 3rd to 4th).
A day or 2 later, my bro suggestes doing the idle re-learn procedure. The instant he disconnected the TPS, the code popped up again. I cleared it again & it stayed off for a couple of days, but then came back.
After reading up on P0505, I decided to replace the IACV this weekend (for fear of frying the ECU). First though, I cleaned the old one and ran the car for 10 mins. At first it started fine and drove fine. When I got back home though, Idle was high again & SES came back on.
I proceeded to replace the IACV. After running the car about 30 minutes, high idle & SES again. I could clear the SES light, but scanner kept picking up the code - SES came back on a few more times.
I then disconnected battery, and did the idle re-learn over a half-dozen times. Codes eventually cleared, but idle remains high (1000 - 1100 RPM). My brother cleaned the MAF & adjusted TPS to no avail (interestingly, when he tried to put it back to its original position, idle shot up to about 2000 RPM with no change with idle re-learn). Since last night, SES light has not come back on, but idle remains high - now it remains high whether cold or hot.
I read the power steering pressure switch can cause P0505 code, but idle does jump when I turn the steering wheel at idle (however this morning the RPMs did dip a couple of times when turning wheel at idle).
Looking for other known issues, suggestions and the procedure for thesting the PS pressure switch...
From My readings, I guess it can be either the MAF, TPS or the power steering high pressure switch. Anyone know how tho test the switch?
Here's some background on the development of the problem:
About a week from last Saturday, I was driving a little more spirited than usual on the highway (about a one hour trip) and when I was close to home, SES light came on: P0505. I cleared the code. Since then though, I noticed the following:
- my idle would be a little high after the car is at full operating temperature (1000 - 1100 RPM; it had done it occassionally in the past, but kind of seldom, so I never gave it much thought).
- Also, the transmission seems to occasionally have displaced shift points (delayed O/D on hard acceleration & delayed shifts - especially from 3rd to 4th).
A day or 2 later, my bro suggestes doing the idle re-learn procedure. The instant he disconnected the TPS, the code popped up again. I cleared it again & it stayed off for a couple of days, but then came back.
After reading up on P0505, I decided to replace the IACV this weekend (for fear of frying the ECU). First though, I cleaned the old one and ran the car for 10 mins. At first it started fine and drove fine. When I got back home though, Idle was high again & SES came back on.
I proceeded to replace the IACV. After running the car about 30 minutes, high idle & SES again. I could clear the SES light, but scanner kept picking up the code - SES came back on a few more times.
I then disconnected battery, and did the idle re-learn over a half-dozen times. Codes eventually cleared, but idle remains high (1000 - 1100 RPM). My brother cleaned the MAF & adjusted TPS to no avail (interestingly, when he tried to put it back to its original position, idle shot up to about 2000 RPM with no change with idle re-learn). Since last night, SES light has not come back on, but idle remains high - now it remains high whether cold or hot.
I read the power steering pressure switch can cause P0505 code, but idle does jump when I turn the steering wheel at idle (however this morning the RPMs did dip a couple of times when turning wheel at idle).
Looking for other known issues, suggestions and the procedure for thesting the PS pressure switch...
04-30-2012, 01:27 PM
#2
Update:
I'm at the shop right now. It's still the IACV, per my wrench. He can control it with CONSULT II, but as soon as he exits menu, it's out of whack again. He sent me to dealer for a new one & told me NO ELECTRIC COMPONENTS FROM AUTOZONE! Will update after new one is installed.
I'm at the shop right now. It's still the IACV, per my wrench. He can control it with CONSULT II, but as soon as he exits menu, it's out of whack again. He sent me to dealer for a new one & told me NO ELECTRIC COMPONENTS FROM AUTOZONE! Will update after new one is installed.
04-30-2012, 04:38 PM
#3
Conclusion
Just got back from the shop. After my wrench installed the dealer-supplied IACV, everything's back to normal. Looks like my ECU skated by.
Moral of the story: Don;t disregard P0505 and definitely, do not get the AutoZone brand!
Moral of the story: Don;t disregard P0505 and definitely, do not get the AutoZone brand!
04-30-2012, 09:44 PM
#4
But wait, there's more...
After driving around all afternoon, P0505 came back on when I left the car idling for a few minutes at the convenience store. Idle slightly high & feels slightly sluggish,but not nearly as bad & engine is not hunting anymore. Back to the wrench tomorrow... 
10-28-2012, 02:03 PM
#5
Newbie - Just Registered
Join Date: Oct 2012
Location: Santa Clara, CA
Posts: 7
Did you ever get this issue solved? I'm having the exact same problems. Cleaned my throttle body and my idle went up to 1000. A few weeks later P0505 popped up making me think my IACV was bad. Replaced the IACV and tried the idle relearn a bunch but can never get it to work. I'm using the procedure from the FSM where you unplug TPS but otherwise no driving issues whatever Any updates appreciated!
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