I have a 2002 1.8t,
threw the codes
p0638 throttle actuator control r/p bank 1
p02221 throttle pedal position switch b circuit range/performance
The car's idle keeps revving high and falling and stalls randomly. At higher rpm's the car seems to run fine and not show any symptoms, but at idle it fails. The exhaust also sounds much different, almost like a diesel, and the engine shakes a lot, and sounds a lot like misfiring? I am pretty sure the car is running rich because i can hear backfire in the exhaust when i let go of the gas. This problem is intermitent and comes and goes, but when it does it leaves me stranded! I recently replaced: the coil packs, maf, sprak plugs, fuel pump, fpr, and cleaned the pcv breather valve (new one coming in the mail) and the throttle body.
Do the codes thrown by the engine mean that my throttle body is bad? or is it an electrical problem with my pedal assembly? Any input is appreciated, i do not have access to vag-com... are these symptoms that i need a Throttle Body Alignment?
Thanks, ben :/
here is a link to the video: http://qik.ly/Qv9PN1aktdDCAp8Tr69gH4
Last edited by pandabear; 09-03-2010 at 11:10 PM.
Check what revision brake light switch you have, older faulty switches cause problems with the pedal position switch. Sounds crazy I know but this is coming from experience. Also for rough starts check your MAP sensor and the other sensor in your intake manifold (forget the name). Both could be oil covered from a bad PCV valve. (also from experience)p02221 throttle pedal position switch b circuit range/performance
Yes, I am still having this problem On my way to a vw shop the car stalled, no brakes, and got in an accident... I took it to Mike at Canyon Racer (if any of you know him) and the issue appears to be intermitent, because when it got to his shop, it worked fine. He checked my pcv breather system and i was missing the o ring which would have caused a big vacuum leak, but since the problem wasn't happening, he couldn't say if he had fixed it. Started my car tonight after getting it back from the body shop, and whadya know the problem returned. It's getting pretty frustrating because the car appears to have nothing wrong. smoke tested it, no leaks.
Oh, and about the brake switch, my brake pedal was clicking the other day when i depressed it but then it went away, would that be what you are talking about? I checked and i do have the green brake light switch from the recall, so i don't know if that would go wrong.
And about the TB, i did not disconnect the battery. I tried the turn the key to ignition and wait method (don't know if it actually works)
If ANYONE has had this problem... and been able to get to the bottom of it, please LMK !!!
Bumping for a cure.
I cleaned my TB a while back, fixed it, then went ahead and replaced it with another one-- no problems for about 5 months. Current problem (EPC and P0638) doesn't seem as bad as before, but still an issue. Gonna try an adaptation soon. Hoping it works.
if you have the old revision brake light switch it could be the problem. Even if its not the problem its worth replacing before you have the sticky light syndrome. May want to consider replacing the map sensor or at least taking it out and cleaning it. Also consider the air intake temp sensor (cleaning will help). Now for good measure read up on cleaning your MAF.
I had this exact problem and replaced my brake light switch and MAP. I then cleaned my MAF, MAP and air intake temp sensor in 90% rubbing alcohol. Put each one in a separate ziplock bag and submerged them in alcohol. I closed the bag and sloshed it around a good bit after leaving it soak for a while. This should clean any oil dirt out of there. Leave it dry I wouldn't suggest blowing on the sensors with any high pressure air source (compressor) unless you are careful and use low pressure.
Also if you don't have a vagcom cable get yourself one off of ebay and get drivers for it here...
This guide may come in handy...
After this get yourself the older copy of vagcom (you may need to do some tricks in order for the software to allow you to perform the following, PM me if you need help)
Go here for a guide on how to perform a TB alignment...
Last edited by travis_gli; 02-22-2011 at 08:13 PM.