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Vauxhall Corsa 1.2 12v X12XE 2000 - Fault code P0505 idle air control - Fixed #

Posted by Pete Mutlow on July 27, 2009, 9:02 pm

Year of Manufacture *: 2000
Engine Code or Type *: X12XE
( Optional ) Scanner used: ACR4 G2

Evening all,

This car has a driveability problem which I can replicate by holding at approx 1800 rpm and after about 10 secs or so, the engine hunts badly. O2 is driven up to about 12% and HO2 sensor sticks at 0v indicating a very lean mixture. Emissions at idle are perfect. Fault codes 1510 (Idle Position Switch) and 0100 (MAF) were present and cleared down OK. PO 0505 (Idle air control) was also present but re-appears when running at approx 1800 rpm. MAF has been replaced by garage and trace is ok on both when pico'd. Disconnect MAF and problem is still there. Disconnected EGR valve and problem still there. TPS checked out ok on scanner (not scoped) going 0.9v to 4.5v with no glitches. Going back on Wednesday to have another look and check such things as fuel pressure and vacuum and anything else you could suggest. I am assuming that PO 0505 is a result and not the cause of the problem......unless someone can advise differently.

Regards

Pete M

Re: Vauxhall Corsa 1.2 ltr - PO 0505 Fault Code

Posted by David Davies <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5218' width='330' height='300' border=0 style='border:none;'> on July 27, 2009, 9:24 pm, in reply to "Vauxhall Corsa 1.2 ltr - PO 0505 Fault Code"
David Davies

When you check the fuel pressure you may find it falling off as speed increases.If you examine the fuel pump you may find that the connecting hose inside the tank which links the pump unit to the outlet pipe is loose or split.An easy repair if this turns out to be the problem.

Re: Vauxhall Corsa 1.2 12v X12XE 2000 - Fault code P0505 idle air control #

Posted by Jim watson <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5178' width='330' height='300' border=0 style='border:none;'> on July 28, 2009, 2:04 pm, in reply to "Vauxhall Corsa 1.2 12v X12XE 2000 - Fault code P0505 idle air control #"

Hi Pete, that code normally means you need a new throttle control motor, have seen it 3 or 4 times.

Re: Vauxhall Corsa 1.2 12v X12XE 2000 - Fault code P0505 idle air control #

Posted by Pete Mutlow <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1569' width='330' height='300' border=0 style='border:none;'> on July 28, 2009, 8:09 pm, in reply to "Re: Vauxhall Corsa 1.2 12v X12XE 2000 - Fault code P0505 idle air control #"
Peter Mutlow

Evening All,

Thanks David and Jim. I cannot believe that a Throttle Control Motor can cause this problem.....or could it? Besides, it had a new one a few months ago. Anyway, will do a few more checks tomorrow including fuel pressure.

The one thing I dislike about visiting garages is that you always get the difficult ones. Also, a few garages I used to visit have now got scanners etc and I have to smile when they ring up and ask what so and so code means etc. Ho hum. Its not what you got but how you use it.

Regards

Pete M

Re: Vauxhall Corsa 1.2 12v X12XE 2000 - Fault code P0505 idle air control #

Posted by Christy Doyle on July 29, 2009, 12:07 pm, in reply to "Re: Vauxhall Corsa 1.2 12v X12XE 2000 - Fault code P0505 idle air control #"
Message modified by board administrator July 29, 2009, 3:13 pm

Peter,
Agree with Jim on P0505 solved problem a few times with IAC,Valve,also Dealer supplies short harness if not already fitted,( at extra cost)
Regards,
Christy Doyle.

Re: Vauxhall Corsa 1.2 12v X12XE 2000 - Fault code P0505 idle air control #

Posted by Mark Robins <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1448' width='330' height='300' border=0 style='border:none;'> on July 29, 2009, 3:55 pm, in reply to "Re: Vauxhall Corsa 1.2 12v X12XE 2000 - Fault code P0505 idle air control #"
Mark Robins

Throttle switch contact will cause injectors to switch off above 1200 - 1400 rpm, will then cycle up and down around this speed, makes driving very interesting! New ISC unit will normally fix this as suggested. You can scope the switch on one of the four wires on the ISC (opens and close when throttle is operated.

Mark.

Re: Vauxhall Corsa 1.2 12v X12XE 2000 - Fault code P0505 idle air control #

Posted by Pete Mutlow <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1569' width='330' height='300' border=0 style='border:none;'> on July 29, 2009, 7:10 pm, in reply to "Re: Vauxhall Corsa 1.2 12v X12XE 2000 - Fault code P0505 idle air control #"
Peter Mutlow

Evening all,

Fuel pressure at just over 3 bar. Received Mark's input about half hour after leaving car already resolved to replace ISC. Your reasoning has now given me more confidence that this will fix problem. What you describe is exactly what is going on. Fix to be posted soon.

Thanks to all for your interest.

Regards

Pete M

Re: Vauxhall Corsa 1.2 12v X12XE 2000 - Fault code P0505 idle air control #

Posted by Gwyn Williams <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5354' width='330' height='300' border=0 style='border:none;'> on July 31, 2009, 1:06 am, in reply to "Re: Vauxhall Corsa 1.2 12v X12XE 2000 - Fault code P0505 idle air control #"
Gwyn Williams

Hiya Pete, scanner should show closed throttle at idle on live data, if not will show symptoms that you have.There is an idle position switch inside the air valve spindle ( I know because I took one apart to try to repair it! i didn't succeed!!). The switch informs the ECU that the throttle is closed and the ECU then goes to the "idle map" for ignition timing and mixture control. If the ECU does not see a closed throttle signal, it will assume an over run fuel cutoff situation and intermittently shut off the injectors.
If the valve was renewed recently, I sympathise with you,as obviously it's reasonable to assume that it wouldn't be faulty. Where did it come from? China, maybe? Regards, Gwyn

Fixed #

Posted by Pete Mutlow on July 31, 2009, 9:11 pm, in reply to "Re: Vauxhall Corsa 1.2 12v X12XE 2000 - Fault code P0505 idle air control #"
Message modified by board administrator August 3, 2009, 3:40 pm

Evening all,

Fitted IAC motor and fault is cured. One thing I did notice and this is an easy test to help diagnose the problem in future. With engine at tick-over gently open the throttle by hand. The IAC "plunger" should follow the motion of the throttle, the faulty one simply re-tracts.

Thanks to all for your interest and replies.

Regards

Pete M

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