Throttle Body Actuator - P0638

seabumb

Member
Joined
Aug 1, 2010
Location
TX
TDI
Golf VI, 2013 Touareg, 2005 Beetle
This code popped up on my 2011 Golf; priority 2 (7500 miles). There is no noticeable difference in the engine performance or driving. I would not know there was a problem except for the ping every 7 seconds and the flashing glow plug indicator. My question here is this: Since the nearest dealership is over 150 mile from me and I don't want to do further damage to the car, does anyone familiar with this code know if the car is safe to drive to the dealership in Houston or do I need to have it towed?

Considering it is not in limp mode and it appears fine I am inclined to drive but as I said, I don't want to do further damage. I called to dealerships there and both had the same basic answer, "we can't tell you that until we hook it up to the computer to see what is actually wrong..."

Thanks for any help or suggestions with this.
 

crashtested

Veteran Member
Joined
Jun 15, 2010
Location
Nelson, BC
TDI
2016 Q5 TDI Technik, 2014 GSW CL 6MT (RIP), 2004 Jetta GLS 5MT (sold), 2010 GSW HL 6MT (buy back)
Call the dealer? If they want it towed it'll be on their bill so no harm, no foul.
 

Rod Bearing

Veteran Member
Joined
Sep 18, 2007
Location
Fort Worth
TDI
Several
Pull the ground cable off the battery for a few mins then put it back. Drive the car normally for a while afterwards.

That same code recently appeared out of the blue and on mine the dealer did what I just described.

It has not returned.
 

seabumb

Member
Joined
Aug 1, 2010
Location
TX
TDI
Golf VI, 2013 Touareg, 2005 Beetle
Thanks for all the quit responses. I could never get the dealership to give me the radio codes. I don't know about VW but all my other vehicles, if you pull the battery you must reset the radio codes. I had to fight Honda about this with an Accord just to get the radio/navigation codes and don't look forward to doing that with VW. It is probably on here somewhere but with the VCDS is it possible to pull those codes?

Roadside assistance... since I am not technically broke, I did not even think about that. Can't help the gray-hair syndrome...
 

RPS99SHO

Veteran Member
Joined
May 13, 2010
Location
Frederick, MD
TDI
2010 Golf TDI
I took my battery out to install my shifter and I did not get asked for a radio code when I started the car back up again.


~ Roman

Sent from my iPhone using Tapatalk
 

DanG144

Top Post Dawg
Joined
Aug 2, 2007
Location
Chapin, South Carolina, USA
TDI
2005 A4 Jetta 5spd
I am not sure when it changed, perhaps 2001?, but the newer VW cars do not need a radio code when restoring the battery. The older ones do. This is as long as the radio is matched with the original vehicle it came with. If you move the radio to another vehicle you need the code.
 

MayorDJQ

Top Post Dawg
Joined
Dec 4, 2001
Location
Williamstown, Mass
TDI
'10 Golf 2dr 6m, sold.
Thanks for all the quit responses. I could never get the dealership to give me the radio codes. I don't know about VW but all my other vehicles, if you pull the battery you must reset the radio codes. I had to fight Honda about this with an Accord just to get the radio/navigation codes and don't look forward to doing that with VW. It is probably on here somewhere but with the VCDS is it possible to pull those codes?

Roadside assistance... since I am not technically broke, I did not even think about that. Can't help the gray-hair syndrome...
Well.....then break it. Leave the headlights on overnight. Call them up and say you tried to jump start it, but no luck.
 

seabumb

Member
Joined
Aug 1, 2010
Location
TX
TDI
Golf VI, 2013 Touareg, 2005 Beetle
LOL, thanks for all the great information. I will go pull the battery now and if it needs a code, go for option 2) "Leave the headlights on overnight..."

Thanks everyone.
 

MayorDJQ

Top Post Dawg
Joined
Dec 4, 2001
Location
Williamstown, Mass
TDI
'10 Golf 2dr 6m, sold.
I would think that as long as it's running normally, and not flashing rapidly, it's OK to drive. The throttle flap works in conjunction with the EGRs and Intake Flaps to control PDF temps. The throttle flap may have defaulted to WOT.

When you shut the engine off, do you hear the soft "EEEEEEEEEEEEEEEEE" from the front of the engine?
 

seabumb

Member
Joined
Aug 1, 2010
Location
TX
TDI
Golf VI, 2013 Touareg, 2005 Beetle
No 'eeeeeeeee' from the engine; no unusual sounds at all.
 

MayorDJQ

Top Post Dawg
Joined
Dec 4, 2001
Location
Williamstown, Mass
TDI
'10 Golf 2dr 6m, sold.
Hmmm. You should be hearing an "eeeeeeeeeee" as the EGRs reset themselves. Maybe if one link goes bad, they all default open.
 

TDIzumSpass

Veteran Member
Joined
Aug 7, 2009
Location
Waukesha Cty, WI
TDI
2009 Jetta Sportwagen TDI 6M
I have the same code, and experienced the check engine solid and glow plug flashing combination, intermittently. In addition, the car will occasionally refuse to start (takes 5-10 tries to get it to start, after which it runs like crap for 5 seconds and then smooth). I ran across the following link, which told me to clean out the throttle body.

http://engine-codes.com/p0638_volkswagen.html

I removed the air hose between the throttle body and the intercooler pip, and cleaned the gunk out from around the round flap/valve just inside the throttle body (quite a PIA without removing the throttle body from the engine, which I will do the next time). Anyway, I just did this tonight so it's too soon to know if it will help.
 

JKC_NC

Veteran Member
Joined
Nov 9, 2009
Location
Raleigh
TDI
'15 Passat TDI DSG | '15 Passat TDI SE Manual (sold 7/2018) | '10 Jetta Wagon TDI manual (sold 4/2015)
I have the same code, and experienced the check engine solid and glow plug flashing combination, intermittently. In addition, the car will occasionally refuse to start (takes 5-10 tries to get it to start, after which it runs like crap for 5 seconds and then smooth). I ran across the following link, which told me to clean out the throttle body.
http://engine-codes.com/p0638_volkswagen.html
I removed the air hose between the throttle body and the intercooler pip, and cleaned the gunk out from around the round flap/valve just inside the throttle body (quite a PIA without removing the throttle body from the engine, which I will do the next time). Anyway, I just did this tonight so it's too soon to know if it will help.
Yesterday morning I had a CEL + erratic throttle response on my way to work. Incidently temps were ~23F, the coldest morning of the season. I kept the RPMs up above 2000 for the rest of the way to work (10 mi). Drove at lunch and home again in the evening, the light on the whole time, but engine seemed normal.
This morning I ran errands, driving normally. The CEL light stayed on the whole time (but no other lights). I had the code read at AutoZone and got P0638: Throttle actuator control range/performance- bank1
Explaination: Failed TPS
Probable cause:
Failed accelerator pedal position sensor
dirty or defective throttle valve
failed throttle valve control module.
As the engine was by now nicely (and gently) warmed up, I decided to see if some exercise might help the situation. I drove the car hard for about 10 miles of acceleration/high RPM driving in 2nd/5th gear, giving it lots of WOT, revving up to 4000, and cruising between 2000 and 3000 with coasting in gear back down to 2000. About 1 mile into the 10 mile drive, I noticed the CEL was no longer lit. Got home and looked up the code and found this thread.
My question...is, if this is a sticky drive-by-wire sensor/actuator, are there parts of the drive-by-wire system that can/should be lubricated? My plan is to lubricate all possible sticking points, if possible, and not do anything else "unless the CEL or hesitation/surging return. I plan to chalk it up to the "cold" temps in the 20s. Do I need to have the codes cleared if the light is off? Any other suggestions?
By the way, I had an episode of the iced-intercooler roughness my first year, and this is not the same. And I'm aware of the "hill-cresting" or "stumbling" and this throttle thing is not related.
Regards,
Joe
 
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panzer

Veteran Member
Joined
Dec 10, 2002
Location
Culpeper, VA
TDI
'10 Golf 2Dr, 6M, & Sunroof
I had the same thing happen to me on the way to work. CEL but no glowplug light. Code was P0638 THROTTLE CM RANGE/PERFORMANCE. Dealer performed GFF Test for wiring and voltage. Code did not return. If it does, they say the throttle should be replaced, estimated cost $696.

From the searching I could find indicated the G69 relay and J338 Throttle Valve Control Module are what the code is referring to. Am i even close? If so, does anyone know what the part numbers are?

Thanks,
R
 

MTjake

Veteran Member
Joined
Jun 2, 2003
Location
Belgrade, Montana
TDI
3
Wife calls today with same complaint: check engine light on, service engine on display, and glow plug light flashing. Oil level normal. Scanned and got P0638, no other codes shown on the Scanguage. I tried disconnecting the negative on the battery for about 15 minutes and now I have two other lights in addition, electro assist steering and ESP errors. When I clear the code it shows back up almost immediately. The car seems to be running normally for the most part, but I did notice a somewhat rough shudder on shutdown and a stronger odor to the exhaust, and a decent amount of water in the tailpipe. My wife took it in for some sort of "scheduled" service to the shifty dealer about 300 miles ago (she thought she was supposed to). Besides an oil and oil filter change, I think they did the fuel filter and a brake flush for some reason. Who knows what else, but they sure charged her for it. Car has approx 65k miles and this is the first problem we've experienced besides the TPMS sensors.

We've had cooler, below freezing, more humid weather lately. Iced intercooler? I will be looking at the hoses tomorrow. Should I drive a 150 mile trip with it tomorrow?
 
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MTjake

Veteran Member
Joined
Jun 2, 2003
Location
Belgrade, Montana
TDI
3
Checked for fluid/sludge in passenger side lower IC pipe just in case. Maybe a couple drops of condensation, no sludge. Went for a drive-decided against running the errand to Billings and only went about 35 miles. ESP and electric steering lights went off right away. For awhile I would get the check engine warning on the MFD with a tone every minute or so. When I clear the code the check engine light goes off but I get flashing glow plug light back right away, along with the check engine msg on the MFD, but I don't get the repeated warning tone with message anymore, just once. Car starts normally. Throttle response seems normal through the entire range of the potentiometer and tachometer. Fuel economy seems normal, maybe better than normal. The only abnomality is the shudder on shutdown and when I checked the tailpipe I could hear an occasional metallic clank coming from the pipe. Exhaust was good and clean again, no strong smell, just the little hint of NH4 or whatever that is normally there.
I guess I will check the throttle tomorrow. Keep driving in the meantime? Try disconnecting the negative battery cable again?
 

hamilton7550

Member
Joined
Apr 16, 2009
Location
Opelika, AL
TDI
2010 Golf TDI 2010 Jetta Sportwagon TDI.
I am having the same problem...throwing code for Throttle Body Actuator Bank 1 .. .I understand that TDI's don't have a TB but a throttle valve ... going to Ross TEch website to check ... any suggestions on cleaning? Ross Tech Wiki says to do an Adaptation. Will do tomorrow.
 
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hamilton7550

Member
Joined
Apr 16, 2009
Location
Opelika, AL
TDI
2010 Golf TDI 2010 Jetta Sportwagon TDI.
I disconnected the battery and cleared the codes with my micro can. MIL came back on with flashing engine light after some driving, but like others it doesn't seem to make much difference. Went to the RT website to see how to do a TB adaptation. When I go into the engine settings there is no TB adaptation routine based upon the RT references. My RT display shows CAN protocol and RT does not cover this protocol. Looks like i need to clean the throttle tomorrow...what to use? Diesel?
 

MTjake

Veteran Member
Joined
Jun 2, 2003
Location
Belgrade, Montana
TDI
3
I used throttle body cleaner and a toothbrush. It was helpful to remove the snorkle and upper airbox to get enough leverage to disconnect the intake hose from the throttle. I don't think I could have done it otherwise. It would probably be worthwhile to remove the top front cowl/grill piece, but I didn't.
 

hamilton7550

Member
Joined
Apr 16, 2009
Location
Opelika, AL
TDI
2010 Golf TDI 2010 Jetta Sportwagon TDI.
Thanks. Going to work on it today. I have been driving it and I noticed the performance was degrading slightly and I get a "bump" when I turn the engine off...so I don't think it's electrical.
 

hamilton7550

Member
Joined
Apr 16, 2009
Location
Opelika, AL
TDI
2010 Golf TDI 2010 Jetta Sportwagon TDI.
So here I am today. I removed the EGR and throttle valve. Both are full of gunk and I'll clean them tomorrow. I haven't messed with the intake manifold at all as I have been warned not to disturb the particles in the manifold. IS there anything else I should do before re-attaching? I did remove the snorkle which helped. IF you want pictures, send me an email.
 

hamilton7550

Member
Joined
Apr 16, 2009
Location
Opelika, AL
TDI
2010 Golf TDI 2010 Jetta Sportwagon TDI.
As I am underneath the car and looking up, I see an accordion metal thing with a black cap that looks like it can be unscrewed...but I don't know what this is for? Is this the EGR cooler?????? Does it have a filter???? It's part of the oil filter...could be water drain.


Afternoon second day: removed the throttle valve and the EGR. Cleaned them both with carb cleaner yesterday and this AM. The EGR was really gunky. Re-installed both and drove it up to temperature this afternoon. Rescanned with VCDS and no codes. Hopefully that was the problem.
God is good.
 
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