2009 Check Engine Light - P048C

Stibz

Veteran Member
Joined
Dec 26, 2005
Location
Philly
TDI
2000 Jetta, 2009 Jetta
First check engine light happened today. The car was just started, and the light came on within a minute. No issues regarding driveability, she ran perfect on the 2 hour trip home with the light on. Here's what I pulled with VAGCOM when I got home;

001164 - Sensor for Exhaust Flap: Implausible Signal
P048C - 000 - - - MIL ON
Freeze Frame:
Fault Status: 11100000
Fault Priority: 2
Fault Frequency: 4
Mileage: 107180 km
Time Indication: 0
Date: 2000.00.00
Time: 19:58:16

Freeze Frame:
RPM: 0 /min
Speed: 0.0 km/h
Voltage: 13.07 V
Lambda: 3.2 %
Lambda: -9.5 %
Bin. Bits: 10011110
Voltage: 1.140 V

After reading several threads about it, and realizing that this part is not covered under the emissions 100k coverage, I'm just gonna keep on truckin...

What fails, the spring mechanism for the butterfly valve or the sensor that controls it? Does anybody know if the bentley or other shop manual provides a testing procedure? TIA
 

Stibz

Veteran Member
Joined
Dec 26, 2005
Location
Philly
TDI
2000 Jetta, 2009 Jetta
I'm going to call VW of North America tomorrow to find out for sure...but from what I read, it seems that the extended emissions system warranty only covers "major" components like the DPF and converters. It's total bullsh*t if it's true...but I've sadly come to expect that from VW.
 

JSWTDI09

Top Post Dawg
Joined
Jan 31, 2009
Location
Las Vegas, Nevada
TDI
2009 JSW TDI (gone but not forgotten)
What fails, the spring mechanism for the butterfly valve or the sensor that controls it? Does anybody know if the bentley or other shop manual provides a testing procedure? TIA
I have read that if you take it to the dealer they just replace the entire exhaust flap assembly for hundreds of dollars. Some people have successfully removed the assembly and cleaned it out and it works perfectly again. If it turns out that it is not covered by warranty, I would suggest trying this first. Are there any gurus near you?

Have Fun!

Don
 

Stibz

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Joined
Dec 26, 2005
Location
Philly
TDI
2000 Jetta, 2009 Jetta
It makes sense that it may be a mechanical failure because the spring and connecting parts are exposed to the elements.

I'll definitely try cleaning it first. I won't have a chance to look at it for a week or two, but it'll be fine. I'm also going to try and see if there's a way to wrap it, or at least partially cover it from road salt, grime, etc....
 

Stibz

Veteran Member
Joined
Dec 26, 2005
Location
Philly
TDI
2000 Jetta, 2009 Jetta
Thanks for the links, read through those today.

Sorry, thought it was 100k. In any case, I'm going to take a better look at in a week or two. I'd rather not deal with VW on whether or not it's under warranty on a relatively minor issue. Also, they have no records on the car since i've done all maintenance since new, so i'm sure they would come up with some argument...even though I have my own records.
 

JSWTDI09

Top Post Dawg
Joined
Jan 31, 2009
Location
Las Vegas, Nevada
TDI
2009 JSW TDI (gone but not forgotten)
I'll definitely try cleaning it first. I won't have a chance to look at it for a week or two, but it'll be fine. I'm also going to try and see if there's a way to wrap it, or at least partially cover it from road salt, grime, etc....
.



I believe that the most common problem is not dirt on the outside of the exhaust flap assy (that would be too easy). IIRC, you must remove it and clean out the inside where soot (or carbon) builds up and "gums up" the works. I doubt that road grime and salt is the problem. Sorry, I wasn't clearer on this in the beginning.

Have Fun!

Don
 

pawel

Veteran Member
Joined
Apr 19, 2008
Location
Naugatuck, CT
TDI
'09 TDI 6 MT, Platinum Gray Metallic, Anthracite Interior
excuse my ignorance, but doesn't this flap do something during a regen?
 

VarmintSlayer

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Joined
Aug 12, 2007
Location
Napanee, Ontario
TDI
2009 Trendline TDI 6spd manual Black
Thought i just read the exhaust flap is used for nox cat regeneration, so it won't be regenerated if it is defective.

The dpf regen shuts down the egr process to help increase exhaust temps.

So the flap won't be doing anything.

Edit: page 55&63 common rail self study guide
 
Last edited:

pawel

Veteran Member
Joined
Apr 19, 2008
Location
Naugatuck, CT
TDI
'09 TDI 6 MT, Platinum Gray Metallic, Anthracite Interior
Thought i just read the exhaust flap is used for nox cat regeneration, so it won't be regenerated if it is defective.

The dpf regen shuts down the egr process to help increase exhaust temps.

So the flap won't be doing anything.

Edit: page 55&63 common rail self study guide
thus it should be covered under the emission system warranty, right?
 

VarmintSlayer

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Joined
Aug 12, 2007
Location
Napanee, Ontario
TDI
2009 Trendline TDI 6spd manual Black
It is not listed under the items that are covered in my owners manual, but then again i am in another country...

I might try taking mine off and try freeing it up today. Just hoping something else will come up so i can put it off some more.:p
 

Stibz

Veteran Member
Joined
Dec 26, 2005
Location
Philly
TDI
2000 Jetta, 2009 Jetta
Quick update:

Drove the car about 300 miles since I cleared the CEL, it's still off....but i'm sure it'll come back soon.

I'll be looking at it either thursday evening or friday...i'll update on what i see.

I've been looking into a high pressure filter to add on the output side of the pump to salvage the rest of the fuel system. There's another thread regarding a company www.normanfilters.com; they sell a filter capable of handling 30,000 psi. I'm looking into it this weekend to get a better idea, but it's gonna be in the works soon.
 

MAW

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Joined
Sep 5, 2003
Location
Rockford, IL
TDI
2009 Jetta Sportwagen
Repaired valve

I had the check engine light come on and go off 3 weeks ago. Had a mechanic I know scan it for me. Called VW and of course this is not covered. Light came on and off for two weeks. This week it stayed on. Took it to the mechanic, and we pulled it off. It was as stiff as a teenager at the Playboy mansion. Pulled off the solenoid half, and soaked the butterfly valve in solvent for 20 minutes, pulled it out and wiggled it back and forth. Tapped the end opposite the spring with a brass hammer and worked it back and forth some more. Soaked it for another 30 minutes, and now as smooth as butter. He cleared the codes, and we road tested it. No problems.

There was no soot by the valve. It seems more like the heat caused the metal butterfly valve and spring to oxidize. Not that difficult to fix, just a poor design. Maybe it will last another 78k miles.
 

pawel

Veteran Member
Joined
Apr 19, 2008
Location
Naugatuck, CT
TDI
'09 TDI 6 MT, Platinum Gray Metallic, Anthracite Interior
I had the check engine light come on and go off 3 weeks ago. Had a mechanic I know scan it for me. Called VW and of course this is not covered. Light came on and off for two weeks. This week it stayed on. Took it to the mechanic, and we pulled it off. It was as stiff as a teenager at the Playboy mansion. Pulled off the solenoid half, and soaked the butterfly valve in solvent for 20 minutes, pulled it out and wiggled it back and forth. Tapped the end opposite the spring with a brass hammer and worked it back and forth some more. Soaked it for another 30 minutes, and now as smooth as butter. He cleared the codes, and we road tested it. No problems.

There was no soot by the valve. It seems more like the heat caused the metal butterfly valve and spring to oxidize. Not that difficult to fix, just a poor design. Maybe it will last another 78k miles.
What was the code that you pulled and which solvent did you use? And, can it be removed without a lift?
 

MAW

Veteran Member
Joined
Sep 5, 2003
Location
Rockford, IL
TDI
2009 Jetta Sportwagen
Don't remember the exact number if the code, but it said exhaust flap error. We used the solvent in the tank. If I did it at home I would use Kroil. I think it could be done without a lift.
 

El Dobro

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Joined
Feb 21, 2006
Location
NJ
TDI
2017 Bolt EV Premier, 2023 Bolt EUV Premier
This remindes me of when you had to clean and lube heat riser valves on older cars.
 

Professor121

Active member
Joined
Mar 26, 2009
Location
Wonder Lake, Illinois
TDI
2009 jetta
My check engine light just came on today . . . vcds said "P048C"
Called up the dealership and they scheduled me for friday morning.
2009 jetta with 29,400 miles on it, still is under full warranty :).
 

Rodya

Well-known member
Joined
Mar 19, 2009
Location
Cleveland, Ohio
TDI
2009 Jetta TDI; 2009 VW Rabbit and 2013 VW Golf Gasser
Another P048C

Just got 09 back from dealer... MIL light on at 23K... invoice stated that "inspection found exhaust flap is corroded and will not move properly..." part was replaced under warranty... no hassles
 

Stibz

Veteran Member
Joined
Dec 26, 2005
Location
Philly
TDI
2000 Jetta, 2009 Jetta
It's been about 1200 miles since my last post in this thread, the CEL light still hasn't come back. Either way, when I find some time I'll take a look at it and possibly take it apart for cleaning...but that's unlikely unless I get another code.
 
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