'04 Sir Limps A Lot; the saga continues

QuickTD

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Feb 25, 2002
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SW Ontario
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2003 Audi A4Q 5spd 2.0 TDI 2056VK R783, 2006 Audi A4Q 6spd 2.0 TDI, 2007 A4Q 6spd 2.0 TDI
Is there a way to defeat the auto-locking "feature"? No matter how many times I drive the car, I can't get used to having to push a little button in order to open the door.
With VCDS, go to "46 central convenience" and then "adaptations" scroll down the list or enter adaptation value 4 "auto locking" or something like that. Change the "1" to "0", save new value and exit.
 

Zeitgeist

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Cascadia
TDI
'04 Variant and Vanagon mTDI
With VCDS, go to "46 central convenience" and then "adaptations" scroll down the list or enter adaptation value 4 "auto locking" or something like that. Change the "1" to "0", save new value and exit.
Cool, thanks!
 

Mozambiquer

Vendor , w/Business number
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1998 VW Jetta TDI. 1982 VW Rabbit pickup, 2001 VW Jetta TDI
Yeah, it's real pretty in person, and the tinted windows really are a nice enhancement of the combo.

Is there a way to defeat the auto-locking "feature"? No matter how many times I drive the car, I can't get used to having to push a little button in order to open the door.
Yes, vcds has a function in the convenience control module to turn auto locking off or auto unlock on. I have mine set up for auto unlock when I turn the car off. Also went in with the free vag-tacho alternative and coded for the rear hatch to be unlocked with the doors. That was so nice! If you look in the scanner sub forum there's a thread on that.
 

Zeitgeist

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'04 Variant and Vanagon mTDI
Ok, I'm back. After all this time and fiddling, it still goes into limp mode if the throttle is opened more than halfway. I just got done pulling the turbo and cleaning out the minor bit of soot built up in there. I'm guessing it's a nearly new unit, so it's not surprising there wasn't much soot. I also replaced the N75, MAF and lower boost hose from the turbo. While the turbo was out I deleted the EGR cooler, but left the unit itself attached to the plug. The turbo was my last hail Mary for a solution, so now I'm unsure how to proceed. Prior to pulling the turbo it was overboosting, but now it indicates that it's failing to reach boost specifications. I've been fiddling with VW, Mercedes and Cummins diesels for over thirty years, and this is the only one which has completely confounded me.

To add insult to injury, during our recent PNW heat wave, the car began to run hot when operated for any period beyond about fifteen minutes. The fan clutch didn't seem like it was locking up as I would expect given the heat, I had to endure running the heater on full in order to lower the temps. FML
 

Zeitgeist

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'04 Variant and Vanagon mTDI
Guaranteed to be the dumbest question you'll read all week:

Is it possible to have limp mode deleted from the ECU?
 

Mozambiquer

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Joined
Mar 21, 2015
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1998 VW Jetta TDI. 1982 VW Rabbit pickup, 2001 VW Jetta TDI
Ok, I'm back. After all this time and fiddling, it still goes into limp mode if the throttle is opened more than halfway. I just got done pulling the turbo and cleaning out the minor bit of soot built up in there. I'm guessing it's a nearly new unit, so it's not surprising there wasn't much soot. I also replaced the N75, MAF and lower boost hose from the turbo. While the turbo was out I deleted the EGR cooler, but left the unit itself attached to the plug. The turbo was my last hail Mary for a solution, so now I'm unsure how to proceed. Prior to pulling the turbo it was overboosting, but now it indicates that it's failing to reach boost specifications. I've been fiddling with VW, Mercedes and Cummins diesels for over thirty years, and this is the only one which has completely confounded me.

To add insult to injury, during our recent PNW heat wave, the car began to run hot when operated for any period beyond about fifteen minutes. The fan clutch didn't seem like it was locking up as I would expect given the heat, I had to endure running the heater on full in order to lower the temps. FML
Have you checked the cam on this one? I don't remember if you mentioned that. Check what the maf specified vs actual are. Have you checked how much vacuum you have?
It may be possible to delete limp mode, but in my opinion, it's not a good idea. Its going into limp mode because there is an issue.
 

Zeitgeist

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Cascadia
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'04 Variant and Vanagon mTDI
I pulled the valve cover and did find there was some minor cam wear. I have a new cam and timing kit waiting for the time to swap them. I fixed some vacuum leaks at the pump when I first got the car, but haven't checked since. I'm still getting used to all the features in VCDS, but only on my phone. I guess I'll need to set up my laptop if I want real time on the road data logging.
 

Zeitgeist

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'04 Variant and Vanagon mTDI
Thanks to the suggestion to check vacuum again, I realized that the PO had reversed the plumbing for the N75. I now have lots more power and it doesn't throw a code, but it did go into limp mode again on the highway--low power. What does it mean if it's going into limp mode with no code and no obvious signs of failure?
 

QuickTD

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Feb 25, 2002
Location
SW Ontario
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2003 Audi A4Q 5spd 2.0 TDI 2056VK R783, 2006 Audi A4Q 6spd 2.0 TDI, 2007 A4Q 6spd 2.0 TDI
Guaranteed to be the dumbest question you'll read all week:

Is it possible to have limp mode deleted from the ECU?
Sure. But on an overboost the turbo would just lunch itself. Probably better to keep the fault codes in place.

Just a thought, but the crankcase vent heater and the N75 have the same connector and can be interchanged. The one with the red/green wire goes to the CCV heater. If you interchange them you will get limp mode as soon as you step on it.
 

Scubanero

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Location
Calgary AB
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2005 Passat Wagon
Thanks to the suggestion to check vacuum again, I realized that the PO had reversed the plumbing for the N75. I now have lots more power and it doesn't throw a code, but it did go into limp mode again on the highway--low power. What does it mean if it's going into limp mode with no code and no obvious signs of failure?
Still sounds like a boost leak. Did you fix your S hose yet? Just because you found one leak doesn't mean there isn't another one somewhere.
 

Zeitgeist

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'04 Variant and Vanagon mTDI
S hose was replaced when I pulled the turbo, though I had successfully patched the old one prior to that. The IC is pretty oily, so I'll probably look there for cracks or plumbing leaks. But, wouldn't it throw a low boost code if that were the cause of low power?
 

borninabus

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Arizona
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B5.5 Passat Wagon: RIP Chief Boy :-( 2013 JSW 6MT
mine would go into limp if you were too hard on the go pedal @ highway speeds, but it always threw a code for the TC lock @ the same time. i replaced the TC and it was better for a while, but eventually went back to the same behavior. it's an international pressure problem, not just the TC.

is your TC locking up properly?
 

Scubanero

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2005 Passat Wagon
S hose was replaced when I pulled the turbo, though I had successfully patched the old one prior to that. The IC is pretty oily, so I'll probably look there for cracks or plumbing leaks. But, wouldn't it throw a low boost code if that were the cause of low power?
I have had limp mode trips from a blown S hose, cracked L hose, chinese S hose, missing O ring and poor snap ring engagement. None of them ever produced a MIL.
 

Zeitgeist

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'04 Variant and Vanagon mTDI
Now that I finally fixed the vacuum plumbing and have boost again, we've been daily driving LB, and loving it. These are wonderful cars. Awesome power and very comfortable. It still occasionally goes into limp mode after being driven a while. The power delivery seems to be not very smooth, as in it's kinda uneven or possibly surgey. I need to build a smoke machine to test the intake for leaks, as I think the boost levels are the cause of the unevenness.

The most annoying thing these days is the emissions error message and beep that goes off all the time because I deleted the EGR. Can someone who's done an ECU "re-flash" or whatever it's called explain how this is accomplished? None of the major players really explain the actual process from the customer's perspective. Is this something I download onto a computer or into a separate device or what? Sorry, I'm obligated to ask one dumb question each time I visit.
 

Nevada_TDI

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Reno, sort of...
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2001 Jetta TDI
In an ALH in VCDS, there is a way to "reduce" the EGR and that will usually fix it
Years ago, for an ALH, someone did a work around, but I don't remember the details.
 

QuickTD

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2003 Audi A4Q 5spd 2.0 TDI 2056VK R783, 2006 Audi A4Q 6spd 2.0 TDI, 2007 A4Q 6spd 2.0 TDI
The logical solution to the EGR/CEL issue would be to "undelete" the EGR. EGR does not hurt power or economy on these cars and they don't suffer much intake clogging if driven in a spirited fashion. I even run functional EGR on my 200+hp BHW track car. EGR is only fully on at light loads, it shuts off completely at full power.

If you really feel the need, the only way to properly delete the EGR is via a tune from one of the tune vendors on this site. You can send them your ECU and they will reflash it. You can also visit one of the tuners dealers if there is one local to you, they will often be able to reflash it while you wait. You can also buy or rent a box that connects to the OBD2 port and loads the tune.
 

Zeitgeist

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'04 Variant and Vanagon mTDI
I've been in the process of raising my chassis with a combination of stock springs and 30mm spacers all around. Things were going well until I started working on the front. The pinch bolt for the upper control arms is rust-welded to the upright and no matter what I try it won't come free. I've tried copious amounts of heat, penetrant, a BFH and a pneumatic hammer. Nothing seems to work.

Any folks with similar issues?
 

Zeitgeist

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'04 Variant and Vanagon mTDI
Limp Bisquick gets a raise.

That was absolutely the worst front end rebuild in my 40+ years of wrenching. Literally every stage fought me. Both the pinch bolts were completely seized, and the second required me unbury my rarely used oxy/ace setup and get the upright cherry red. Hated the whole affair.

Anyhoo, it's going in for an alignment this afternoon. Sneak peek:

 

Mozambiquer

Vendor , w/Business number
Joined
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Versailles Missouri
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1998 VW Jetta TDI. 1982 VW Rabbit pickup, 2001 VW Jetta TDI
Limp Bisquick gets a raise.

That was absolutely the worst front end rebuild in my 40+ years of wrenching. Literally every stage fought me. Both the pinch bolts were completely seized, and the second required me unbury my rarely used oxy/ace setup and get the upright cherry red. Hated the whole affair.

Anyhoo, it's going in for an alignment this afternoon. Sneak peek:

That looks great! Where did you get the spacers? I'm considering lifting my beater Passat wagon to give a little more ground clearance.
 

Zeitgeist

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'04 Variant and Vanagon mTDI
I got the spacer kit off of ebay from an outfit in Russia called AK-Tuning. It fit just fine, but the fit and finish was kinda DIY. It works well, and I'm happy with the height. My wife hated the H&R springs that had been on there, so this should suit us ok.
 

Zeitgeist

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'04 Variant and Vanagon mTDI
So, in my endless quest to kill off limp mode for good, I finally broke down and smoked the intake tract. As suspected, the IC leaks pretty good. Does anyone know if Mk4 ALH ICs will fit roughly in the same space, or what dimensions of FMIC can be fit behind the bumper cover?
 

QuickTD

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SW Ontario
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2003 Audi A4Q 5spd 2.0 TDI 2056VK R783, 2006 Audi A4Q 6spd 2.0 TDI, 2007 A4Q 6spd 2.0 TDI
ALH intercooler is completely wrong. A B5.5 1.8T passat unit fits fine though. It has a map sensor in the top tank, but just ignore it. I have about 10 of those intercoolers, but they are too big and bulky to ship.
 

Zeitgeist

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'04 Variant and Vanagon mTDI




I deleted annoying things which got in the way of my never ending diagnostics in the pursuit of a limp mode free existence. The relocated N75 is the big get here, as it actually allows me to access it on the fly without tearing the engine apart. I measured 15 in/Hg @ the inlet to the valve and was told elsewhere on the interwebz that the figure should be closer to 20-25". Is the grommet between the vacuum pump and bulkhead still available, or is that part of the whole hose/pipe assembly?
 

Mozambiquer

Vendor , w/Business number
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TDI
1998 VW Jetta TDI. 1982 VW Rabbit pickup, 2001 VW Jetta TDI




I deleted annoying things which got in the way of my never ending diagnostics in the pursuit of a limp mode free existence. The relocated N75 is the big get here, as it actually allows me to access it on the fly without tearing the engine apart. I measured 15 in/Hg @ the inlet to the valve and was told elsewhere on the interwebz that the figure should be closer to 20-25". Is the grommet between the vacuum pump and bulkhead still available, or is that part of the whole hose/pipe assembly?
Ah, so that was you. 😄
I commented on your Facebook post asking about the issue. Is that grommet where it's leaking?
 

Zeitgeist

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Cascadia
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'04 Variant and Vanagon mTDI
I'm pretty sure the grommet is the source of the leak. I've tried to seal it a couple times, but I don't think I've been successful.
 

Mozambiquer

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Joined
Mar 21, 2015
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Versailles Missouri
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1998 VW Jetta TDI. 1982 VW Rabbit pickup, 2001 VW Jetta TDI
I'm pretty sure the grommet is the source of the leak. I've tried to seal it a couple times, but I don't think I've been successful.
If you pull the hose out of that grommet, and check the vacuum there, how much do you have?
 

Zeitgeist

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'04 Variant and Vanagon mTDI
I measured about 23.5 in/Hg at that port, so I gooped it up real good and then put a hose clamp around the grommet. I kinda think/hope that was my last issue...maybe. I was able to drive a test loop around town and not throw a code, and was able to do a full throttle pull for the first time. I'll update again in a few days. Thanks!
 

PickleRick

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Nov 29, 2017
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Greenville sc
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05 GLS BHW sedan 5 speed conversion. BHW Carver SantaCruz in progress
If you need an intercooler let me know. Just pulled one out, the engine is going into a 4 runner so I'm not reusing it. I've never heard of one failing so I don't see a need to keep it for my DD passat.
 
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