P0638 Code After 82mm install?
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2003 cl55 (sold)
P0638 Code After 82mm install?
Do you have to switch pins from 74mm to Mercedes 82mm throttle body? I know you had to for the 74mm to 80mm, but I didn't think you had to for the 82mm, but might be wrong? Anyway, this is what happened:
Put Mercedes 82mm throttle body in. Got P0638 code and at idle, car goes in limp mode and shows ESP warning (white letters not red) and CEL. No power, pressing accelerator does nothing. Turn key off and on, it resets and if I'm at idle, it triggers limp mode, ESP, etc. again. Drove on freeway, seemed ok, but at idle, it messes up every time.
Idle is at 4-5% (too much) and when in limp mode goes to 7%. I did throttle body reset, etc. Bought the TB used. Could just be a bad throttle body? Wish I had one that I know works to try. Any thoughts?
Put Mercedes 82mm throttle body in. Got P0638 code and at idle, car goes in limp mode and shows ESP warning (white letters not red) and CEL. No power, pressing accelerator does nothing. Turn key off and on, it resets and if I'm at idle, it triggers limp mode, ESP, etc. again. Drove on freeway, seemed ok, but at idle, it messes up every time.
Idle is at 4-5% (too much) and when in limp mode goes to 7%. I did throttle body reset, etc. Bought the TB used. Could just be a bad throttle body? Wish I had one that I know works to try. Any thoughts?
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From: Dago, CA
2003 cl55 (sold)
Any ideas people? P0638 is "Throttle Actuator Control Range/Performance (Bank 1)." After a quick Google check, seems like most of the time a new TB cures the problem.... Will have to check pins and harness to make sure nothing is screwy.
I'm pretty sure no rewiring is needed, correct?
The throttle body reset is the same as the ECU reset, correct?
A couple of questions: Is there a way to check if the throttle body is bad or not? I guess I would need another throttle body to check. And if it is, is it repairable or can it be refurbished or is it trash?
I'm pretty sure no rewiring is needed, correct?
The throttle body reset is the same as the ECU reset, correct?
A couple of questions: Is there a way to check if the throttle body is bad or not? I guess I would need another throttle body to check. And if it is, is it repairable or can it be refurbished or is it trash?
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From: Dago, CA
2003 cl55 (sold)
P0638 indicates actual throttle position is not consistent with inputted value. I'm thinking potentiometer problem? The only other person I can find with a P0638 code is guysandiego and he had to replace TB (I believe this to be true, but correct me if I am wrong).
Last edited by jicl55; May 6, 2010 at 08:51 PM.
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Pin swap is not needed for MB 82mm TB.The only reason the 80mm and Audi 82mm needs a pin swap is because the throttle blade opens in the opposite direction. You need to reverse the polarity of the motor so that the blade actually opens. Alot of people with 82mm TBs have gotten this error. Not sure that the root cause has been found. Usually swapping to another TB solves it. TB reset is a good Idea though. Good luck.
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From: Jacksonville, Florida
2006 E55 AMG --old cars -- E39 M5, 2.7tt Audi S4, E36 M3 **Ducati 996, 748
well, i got my car back from the dealer -- i got a new TB because i have a warranty but i will be throwing my old one back on ... Dealer doubts I got the ESP problem and limp mode because of the TB -- he thinks its because my alternator was putting out a whopping 7.2 volts !!! -- which can make everything go hay wire -- Anyways, i will not put the old TB on right away -- I want to make sure everything is running correctly 1st -- later i will swap it out and see.
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From: Dago, CA
2003 cl55 (sold)
Well, one of the pins was not quite in, so it is working a lot better now. No ESP and no limp mode. The problem now is: Upon startup in park and warmup, it will sit at 1500 rpm and not drop down unless I throw it in gear. And I am getting CEL, I'll have to check the code right now, but I think last time was something like "higher rpm (or idle) than normal" or something to that effect......
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Started it up this morning after sitting all night. Engine started and warm up was normal. Went to 1200-1300 rpms, then dropped to 950. And driving was normal. Before it had been sputtering at idle, like a lack of fuel perhaps? CEL light was on: P0505 Idle Control Module and P0507 Idle Control Module RPM Higher than expected. Cleared the codes, started it up and in warmup mode got stuck at 1500 rpms again. Did throttle body reset then, and it began sputtering at idle like its trying to compensate for the extra air, but can't dump enough fuel possibly? Shouldn't be related to the codes I'm getting tho?
Haven't gotten it tuned yet, but didn't think tune would help with CEL codes or be able to adjust idle.
After I clear the codes, and at warm up in park, when it gets stuck at 1500 rpms, absolute throttle position is at 2-3%, which is what it should be with stock throttle body. I put it in gear, and throttle position eventually drops to 1% to .8% at 650rpm in drive.
Maybe leak somewhere now? Or is there a way to adjust the idle through STAR or programming?
Weird.
Haven't gotten it tuned yet, but didn't think tune would help with CEL codes or be able to adjust idle.
After I clear the codes, and at warm up in park, when it gets stuck at 1500 rpms, absolute throttle position is at 2-3%, which is what it should be with stock throttle body. I put it in gear, and throttle position eventually drops to 1% to .8% at 650rpm in drive.
Maybe leak somewhere now? Or is there a way to adjust the idle through STAR or programming?
Weird.
Last edited by jicl55; May 7, 2010 at 02:33 PM.
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2005 E55
Im sorry to read this thread,but you are going threw the mess I just went threw.I gave up on my 82mm tb and went back to stock.
I wasnt having the drivability problems like you,just the tps was at .8-1.1 in gear and would eventually throw the 505codes and put the car in a limp mode.
my last resort before giving up was to bring the idle up with star,but never got around to doing it.I figured it would of throw the idle too high code that I got a few times also.
make sure your tb is not binding up on anything,I got the crazzy limp and all the t/c errors and the car went nuts when the tb ate my gasket and got the blade stuck in one position.
so maybe your tb has a spot where it binds up and is causing your idle problems.
just a heads up,hope it works out.
you can also try switching your tps sensor off the old tb to the new one and do a reset.
unplug tb
key in second position(wait 10 seconds)
key off
plug tb back in
key in second position for like 2 min(you will hear the blade moving back and forth as it calibrates)
I wasnt having the drivability problems like you,just the tps was at .8-1.1 in gear and would eventually throw the 505codes and put the car in a limp mode.
my last resort before giving up was to bring the idle up with star,but never got around to doing it.I figured it would of throw the idle too high code that I got a few times also.
make sure your tb is not binding up on anything,I got the crazzy limp and all the t/c errors and the car went nuts when the tb ate my gasket and got the blade stuck in one position.
so maybe your tb has a spot where it binds up and is causing your idle problems.
just a heads up,hope it works out.
you can also try switching your tps sensor off the old tb to the new one and do a reset.
unplug tb
key in second position(wait 10 seconds)
key off
plug tb back in
key in second position for like 2 min(you will hear the blade moving back and forth as it calibrates)
Last edited by skratch77; May 7, 2010 at 03:01 PM.
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From: Dago, CA
2003 cl55 (sold)
Im sorry to read this thread,but you are going threw the mess I just went threw.I gave up on my 82mm tb and went back to stock.
I wasnt having the drivability problems like you,just the tps was at .8-1.1 in gear and would eventually throw the 505codes and put the car in a limp mode.
my last resort before giving up was to bring the idle up with star,but never got around to doing it.I figured it would of throw the idle too high code that I got a few times also.
make sure your tb is not binding up on anything,I got the crazzy limp and all the t/c errors and the car went nuts when the tb ate my gasket and got the blade stuck in one position.
so maybe your tb has a spot where it binds up and is causing your idle problems.
just a heads up,hope it works out.
you can also try switching your tps sensor off the old tb to the new one and do a reset.
unplug tb
key in second position(wait 10 seconds)
key off
plug tb back in
key in second position for like 2 min(you will hear the blade moving back and forth as it calibrates)
I wasnt having the drivability problems like you,just the tps was at .8-1.1 in gear and would eventually throw the 505codes and put the car in a limp mode.
my last resort before giving up was to bring the idle up with star,but never got around to doing it.I figured it would of throw the idle too high code that I got a few times also.
make sure your tb is not binding up on anything,I got the crazzy limp and all the t/c errors and the car went nuts when the tb ate my gasket and got the blade stuck in one position.
so maybe your tb has a spot where it binds up and is causing your idle problems.
just a heads up,hope it works out.
you can also try switching your tps sensor off the old tb to the new one and do a reset.
unplug tb
key in second position(wait 10 seconds)
key off
plug tb back in
key in second position for like 2 min(you will hear the blade moving back and forth as it calibrates)
It throws P0505 and P0507 now. But it doesn't go into limp mode. Feels almost like it is sticking somewhere perhaps. I was driving slow, low rpm, no change in accelerator pedal position, and felt rpms drop slightly all of a sudden, then it starts sputtering at idle. But it will not go in limp mode now.
This morning, started and running great, but CEL light was on. No sputtering, smooth idle, etc. Just cleared the codes and started it back up and is started sputtering right away, getting stuck at 1500 in warm up, etc.
Seems like a calibration issue and the ECU is unable to compensate and is trying to dump mass fuel in. I'll check it again and try your TB reset procedure to see if it helps.
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2006 E55 AMG --old cars -- E39 M5, 2.7tt Audi S4, E36 M3 **Ducati 996, 748
too much air is getting past the TB flap at idle -- hints the high RPM -- and/or you have a vacuum leak somewhere -- I imagine its the extra air flowing through that 82mm TB --
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From: Dago, CA
2003 cl55 (sold)
Before I had several problems: think throttle body was not compatible and I have a leak in the brake booster. Few more solutions I'll try before I give up tho.... Misery loves company, no?
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2003 cl55 (sold)
Couple of things left to do. Will try this weekend:
1. Run smoke through lines and see if there is a leak somewhere.
2. See if I can adjust/adapt TB in STAR somehow or adjust idle to TB position and compensate for higher revs.
1. Run smoke through lines and see if there is a leak somewhere.
2. See if I can adjust/adapt TB in STAR somehow or adjust idle to TB position and compensate for higher revs.
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2003 cl55 (sold)
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From: Dago, CA
2003 cl55 (sold)
Tried this, saw TB flap move up (about 20% maybe) and close real quick then nothing. Didn't seem to help a whole bunch tho. I'll try again just in case.
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2005 E55
I messed with my 82mm tb for about 2 months,It never ran rough and the idle was smooth as silk.
Its not an air leak,I went to the point of pulling every line on the car and let the thing have the biggest air leak and it still idles fine.
the codes come from the ecu wanting to see 2.7 degrees at its set idle rpm,now your not going to get this with a 82mm tb because your letting more air in at the same blade angle,some cars are less prone to this and others like mine would throw the code in 5 min.
the car is in a limp mode when the code is thrown,I went from 460whp with cleared ecu to 413whp with the pending codes so its def doing something.
one way I was getting around the codes and limp mode was to put the car in N at every light and never let the car idle in drive.The second the car sees 550rpm and the tps at 1.1 it will flag the code.
here is my car not even a week ago taken apart for like the 3rd time trying to get it to work.I was running a 997 gt3 82mm tb with the wires switched around.
good luck bro,trust me I know how frustrating this can get.
I paid the dealer to reset the tb calibration and it didnt do anything.my last resort was to up the idle by like 40rpms but never got around to it.before messing with star I would get the car to run and drive like normal.My car drove like stock,perfect idle and smoth power band with the 82tb just threw the damn codes.So before taking it in make sure you get the car running right.
i got so frustrated that I turned my car back to stock lol
Its not an air leak,I went to the point of pulling every line on the car and let the thing have the biggest air leak and it still idles fine.
the codes come from the ecu wanting to see 2.7 degrees at its set idle rpm,now your not going to get this with a 82mm tb because your letting more air in at the same blade angle,some cars are less prone to this and others like mine would throw the code in 5 min.
the car is in a limp mode when the code is thrown,I went from 460whp with cleared ecu to 413whp with the pending codes so its def doing something.
one way I was getting around the codes and limp mode was to put the car in N at every light and never let the car idle in drive.The second the car sees 550rpm and the tps at 1.1 it will flag the code.
here is my car not even a week ago taken apart for like the 3rd time trying to get it to work.I was running a 997 gt3 82mm tb with the wires switched around.
good luck bro,trust me I know how frustrating this can get.
I paid the dealer to reset the tb calibration and it didnt do anything.my last resort was to up the idle by like 40rpms but never got around to it.before messing with star I would get the car to run and drive like normal.My car drove like stock,perfect idle and smoth power band with the 82tb just threw the damn codes.So before taking it in make sure you get the car running right.
i got so frustrated that I turned my car back to stock lol
Last edited by skratch77; May 7, 2010 at 11:26 PM.
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From: Jacksonville, Florida
2006 E55 AMG --old cars -- E39 M5, 2.7tt Audi S4, E36 M3 **Ducati 996, 748
So basically the problem is known ---- due to the larger amount of air @ idle with the throttle blade @ ~3% -- the car will throw codes ---- So, is there any solutions to remedy these annoying codes and in some rare instances major limp mode ---- How are all these people running larger TB??? are they just content with that annoying check engine light? --- or are they able to get the super picky ecu to accept the larger TB?
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E55
I do not recommend this but I'm just providing food for thought. These throttle bodies learn what closed and WOT position are, there are no stops to adjust per say and no adjustments for TPS sensor.
With throttle body in hand, you can see that the throttle blade will close a little bit more if you push the blade. Once you remove the sensor cover plate, you can see where the non adjustable cam hits with the throttle in the closed position as well as WOT. The closed and open position can be altered, though not easily. You would be taking a shot in the dark, but you could reduce the closed position of the throttle, which in turn might get you up to the required % at idle.
With throttle body in hand, you can see that the throttle blade will close a little bit more if you push the blade. Once you remove the sensor cover plate, you can see where the non adjustable cam hits with the throttle in the closed position as well as WOT. The closed and open position can be altered, though not easily. You would be taking a shot in the dark, but you could reduce the closed position of the throttle, which in turn might get you up to the required % at idle.
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From: Dago, CA
2003 cl55 (sold)
Yeah, put mine back to stock. Not sure if it is something I did wrong, or install, or vacuum leak or TB itself or what. But if anyone is interested and wants to try it, PM me or email. Looking for $450, which is what I paid for it. Will also post in classified section. Thanks
