Code P047A - Exhaust Pressure Sensor 2

[mihneagabriel]

I know this topic has been discussed before but I'm still extremely lost on where this sensor is located and what exactly the part number is for it.

This is the code that I received:

1 Fault Found:

001146 - Exhaust Pressure Sensor 2
P047A - 000 - Open Circuit - MIL ON
Freeze Frame:
Fault Status: 11100000
Fault Priority: 2
Fault Frequency: 1
Reset counter: 255
Mileage: 127234 km
Time Indication: 0
Date: 2000.00.00
Time: 10:53:44

Freeze Frame:
RPM: 0 /min
Speed: 0.0 km/h
Temperature: 26.1°C
Temperature: 85.5°C
Temperature: 78.0°C
Pressure: 0 mbar
Pressure: 5 mbar

The parameters on the DPF look right so I highly doubt the DPF is cracked like some were saying.
Now, can someone provide the part number I will need and maybe a picture of their bentley manual? btw, i dont have a problem with buying a new manual if i were planning to keep the car (i bought a laptop and vag-com cable for this) but I'm looking to trade in the car on monday and I'm assuming I'd get a better deal on it if there wasnt a CEL for just a simple sensor. I'm in no way a complete noob on changing parts out but sensor wise and whatnot I'm lost.

Any and all help is greatly appreciated! pictures of where the sensor is, part number, etc.

Thanks guys!

(dont worry I'm trading into another TDI so im staying in the family)

 

[JSWTDI09]

There are 2 differential pressure sensors and both of them are relatively easy to get at from the top side. One of them is right above the Aux Fuel pump and the other is right above the DPF between the cylinder head and the firewall (it is snapped into an insulating "blanket"). Since you have a 2009 they are probably both p/n 076 906 051 A sensors. If you can find one, you can replace one sensor and reset the sensor and see what happens. You have a 50/50 chance of picking the right one the first time. If the problem comes back replace the other one with the one you removed before, reset and try again.

If you want to be sure you fix it the first time buy 2 of p/n 076 906 051 B sensors and replace them both. There are more details in this thread: http://forums.tdiclub.com/showthread.php?t=412579

Have Fun!

Don

 

[mihneagabriel]

You are a life saver! So about the part number split half way through 09, should i just give them my vin and have them find the right part or just give them the pn you gave me?

also, i found this picture, would that be the correct location?

Thanks again! life (and money) saver!

 

[mihneagabriel]

Update**
For all other who have this problem.
I was able to replace the sensor today. I went and bought a new sensor from the dealer (pn: 076 906 051 B; price: $98.80 before tax) I only purchased one because I doubt 2 of the same sensors can fail at the same time (I have been wrong before though). I decided to replace the easier of the 2 sensors (the one by the hood support strut as shown in the above picture). It is mounted to a bracket which needs to be removed. 3 screws need to be removed (T30), one for the bracket, one for the sensor, and one for a bracket that holds the hoses that are attached to the sensor. The hoses are held onto the barbs with some spring hose clamps. squeeze them with pliers and slide them down the hose then remove hose.
Long story short (after recalibrating the sensors and clearing the code) the code came back up repeatedly.
So it had to be the other sensor. I swapped the sensor back (thinking that if it is both sensors, I can buy another one and swap it out quickly).

The sensor behind the oil fill cap was next. that sensor is wrapped in a heat protective cover with some clips. its a bit harder to get to and make sure the engine has had time to cool (the head protector is a hint). The sensor is mounted to a bracket. the bracket has to be removed and is bolted down with a T30 bolt. the sensor is mounted to the bracket with a triple square bolt (i dont remember the exact size). the hoses to the sensor are also covered in a heat protective cover so its hard to get to the hose clamps. (my sensor only had a clamp on one hose). The sensor had the same p/n but looked different than the new one and the one by the hood strut. after replacing the sensor, calibrating the sensor and erasing codes the code is now gone.

TL;DR: rear sensor was an older version on my car, the "2" in "001146 - Exhaust Pressure Sensor 2" seems to indicate the rear sensor needs replacing. the rear sensor is harder to get to. make sure you let the engine cool. recalibrate the sensors before resetting code.


NOTE** VCDS states that after typing in the code to recalibrate the sensors the ignition needs to be put in the off position and remain there for at least 30 seconds.

good luck to anyone needing to do this.

 

[axnels2]

Hey guys, I just experienced the same issue..1 Fault Found:
001146 - Exhaust Pressure Sensor 2
P047A - 000 - Open Circuit - Intermittent - MIL ON
Freeze Frame:
Fault Status: 10100000
Fault Priority: 2
Fault Frequency: 5
Reset counter: 255
Mileage: 93485 km
Time Indication: 0
Date: 2000.00.00
Time: 17:32:06

Freeze Frame:
RPM: 0 /min
Speed: 0.0 km/h
Temperature: 28.8∞C
Temperature: 79.2∞C
Temperature: 66.0∞C
Pressure: 0 mbar
Pressure: 28 mbar

Readiness: 1 1 0 0 0 .

So I will be buying me a new pn: 076 906 051 B... A question that I have is, I have not found a "recalibrate the sensors" procedure in VCDS manual. Can someone enlighten me on what needs to be done in baby steps, as i am very new to VCDS?

 

[JSWTDI09]

So I will be buying me a new pn: 076 906 051 B... A question that I have is, I have not found a "recalibrate the sensors" procedure in VCDS manual. Can someone enlighten me on what needs to be done in baby steps, as i am very new to VCDS?

You have a 2009 car. Most 2009 cars use the 076 906 051 A sensor. If you want to change to the "B" version you have to replace both sensors. Check the one over the AUX pump and look at the p/n. If it an "A" model, buy an "A' model as a replacement. A VW dealer can also look up your VIN and tell you if you need an A or a B sensor. Either sensor will work but they both must be the same type. You cannot have an A on one sensor and a B on the other.

As for the recalibrate sensors, it is easy. Open up the engine controller and click on "Advanced Coding", you will see a pop up box gining you 3 (or 4) choices. One of them says something like "reset DPF pressure sensors" and it will give you a number to enter (I don't remember what it is). Then just type that number into the coding box and press "do it". It is really that simple.

Have Fun!

Don

P.S. I have been involved with 2 of these pressure sensor replacements, because I have VCDS. In both cases it was the sensor above the DPF that failed, not the easier one to replace (the one over the aux fuel pump). I suspect that the heat from regenerations shortens the life of these sensors.

 

[axnels2]

Never mind. It appears that I have found my answer in a different thread:

http://forums.tdiclub.com/showthread.php?t=412579


Start VCDS
open controller #1 (engine)
click on the button marked "Advanced Coding"
There will be a window near the bottom of the screen where you can enter a number.
A pop-up window will appear with 3 or 4 choices, one of them will say something about "reset DPF pressure sensors" or something close to that. It tells you to enter a 5 digit code.
Enter that code in the window and press the button that says "do it".
You will see a message that says "coding accepted"
Clear fault codes (if any)

 

[axnels2]

JSWTDI, thank you for your reply. I just read your post. I did not realize you have answered my question before I posted my last message... Was not trying to be disrespectful.

 

[jcreinman]

I have an 09 and got the error code P047A for exhaust pressure sensor 2. I purchased two new sensors model "B" as per the earlier post, but this did not work. I then got the error codes about implausible signal for both sensors.

I took my old sensors and checked the resistance between pins 1 and 2 and between 2 and 3 and found that the sensor #2 (behind the oil filler cap) was open loop (infinite resistance) on both sets of pins. The sensor #1 has readings. So I put sensor #1 back in, and ordered a new generic Bosch 0281002710 sensor and put it in for sensor #2. Voila, no more codes.

So you can check the sensors to see which is bad based on the resistance. Also the 09 model will not work with the B model sensors even if you have two matches ones (at least my vehicle did not like it). The generic Bosch sensor is much cheaper to buy as well.

 

[JSWTDI09]

Also the 09 model will not work with the B model sensors even if you have two matches ones (at least my vehicle did not like it). The generic Bosch sensor is much cheaper to buy as well.

Yes, this is true. Originally we thought that an '09 would work if both sensors were replaced with the "B" version. It turns out that this is not true. A 2009 TDI needs the "-A" version of this sensor and the 2010+ TDIs need the "-B" version. I do not know exactly what the difference is between them, but for an '09 car you need the "-A" sensor.

Have Fun!

Don

 

[meerschm]

Follow on, since this thread is the first to show up searching for P047a

I replaced my sensor, 1 in the following diagram. (on my 2009 TDI JSW)

Exhaust pressure sensor 2 is the one across the low pressure EGR, not the one across the DPF.

the adaptation (coding) in VCDS is for the one across the DPF.

I also remember having scanned the car of a user who stopped by, having replaced his sensor, and we just verified that the DPF was regenerating fine, and no codes. his MIL went out by just driving.

http://forums.tdiclub.com/showpost.php?p=4855440&postcount=8

so the main point here is that it does not seem to me that you need to run any coding for the exhaust pressure sensor 2. the coding is for pressure sensor 1 (G450)

if you have a VCDS and have a question on which sensor is which, you could unplug one and verify that the error remains consistent. (others have posted that the locations switched in later model year cars) (this would also be a good idea if you want to verify you are changing the correct sensor before the complete removal)

if you do not have a VCDS, but have that P047a exhaust pressure sensor 2 code, you should be able to replace and go, without a VCDS.

I went ahead and ran the coding, on the old sensor, and the measured soot level went to zero for a couple DPf regen cycles, seems like it is back to normal now.

 

[mdl3r1]

My 09 Jetta TDI Sedan ALSO has P047A - Exhaust Pressure Sensor 2...pic of sensors?

Exhaust pressure sensor 2 is the one across the low pressure EGR, not the one across the DPF.
the adaptation (coding) in VCDS is for the one across the DPF.
so the main point here is that it does not seem to me that you need to run any coding for the exhaust pressure sensor 2. the coding is for pressure sensor 1 (G450)
if you do not have a VCDS, but have that P047a exhaust pressure sensor 2 code, you should be able to replace and go, without a VCDS.

Excellent info, Meerschm! (and others as well).
My question/request now is, to make sure I understand correctly:
I have the exact same code, intermittent, etc. But, the picture you submitted for the location of the sensors does not show in my thread/browser, I dunno.
Can anyone post a better pic showing which is Sensor 2 and which is 1? I get that they are both the same Part Number, and that meerschn states that Sensor 2 ("my sensor") will not VCDS adaptation. (This is great, bc I don't have one now, though I plan to get one ASAP!). So this post was the clincher I needed to ice the cake of the threads I've read on here...
I am fed up with my dealer which missed this code to begin with, charged me $480 for an Oxygen Sensor part/install 2 weeks ago, only for the code P047A to come back on the next day!
They just told me they can't have me come in tomorrow to fix it bc it may require deeper Tech Line Support which is not open Saturdays, plus the Service Manager is not in Saturdays either, so I'm outta luck...can't take off work on weekdays, nor travel 1 hour to them again...
Much gratitude and respect to y'all veteran TDI's who help us grow...and on this particular thread...including but not limited to JSWTDI09, oilhammer, etc etc
I am ready to start buying some basic tools, a VCDS cable, and get to it! Tired of feeling helpless with dealer's retail and "we have no time" attitudes...nice folks but...the dealer system leaves one hung out to dry and grab your checkbook...no more. Same way I learne to build computers from parts, I have now watched enuff videos to do most simple things myself.
Speaking of which...which Torx is the one for removing the Sensor?? I think I can do that, unclamp it and undo the 2 hoses, and replace...
Thanks again, folks!

 

[meerschm]

http://pics.tdiclub.com/showphoto.php?photo=116396&title=1-exhaust-parts-location&cat=all

see if this link works. the image is on this site.

I needed a triple square and a torx. a mirror helps see what is going on behind the sensor, it is the one behind the oil fill.

I want to say it is a T-30 and XZN 8 but don't count on this for more than a first guess.

the hose clamp was a little tricky to get to.



tools and data are always a good thing I really have had fun with the VCDS, in addition to all the money I have saved using it.

 

[mdl3r1]

Thanks for the reply. And I just did look in the diagram better. Thanks.

So, # 1 in the diagram is the one you changed, correct? That is the one behind the oil fill. Indeed, a mirror was my thought, as I went out and looked at it after I posted. It's "backwards"...lol.

Now, is this the one you replaced, bc you had P047a, and so THAT is "Sensor 2"?

I was thinking Sensor 2 is the other one, withOUT the silver wrap and is # 33 on your diagram, to the left near the hood arm?

So, the one that does NOT need VCDS is the one behind oil fill?

Sorry for confusion...

 

[meerschm]

on my car, also a 2009 (but a wagon, not that I think that makes any difference)

I changed the one marked 1 in the diagram, removed items 2 and 3, (one is torx other is triple square XZN) and the clamp on tubing marked 5.

this is wrapped with silver colored snap-in insulation, and is located between the firewall and the oil fill.




my reported error (befor I changed it, now cleared), as logged by VCDS follows:

001146 - Exhaust Pressure Sensor 2
P047A - 000 - Open Circuit - Intermittent - MIL ON
Freeze Frame:
Fault Status: 10100000
Fault Priority: 2
Fault Frequency: 6
Reset counter: 255
Mileage: 257533 km
Time Indication: 0

Freeze Frame:
RPM: 0 /min
Speed: 0.0 km/h
Temperature: 1.8°C
Temperature: 64.8°C
Temperature: 48.0°C
Pressure: 0 mbar
Pressure: 3 mbar


Readiness: 1 1 0 0 0



​

 

[mdl3r1]

OK, so you changed the one behind oil fill, wrapped in the silver "blanket"...

So, THAT is the one that does NOT need adapting, in your previous post, correct? Did you just drive it and MIL went off? Or did you adapt for this one in diagram.....

Here's my VCDS code...essentially the same!:
001146 - Exhaust Pressure Sensor 2
P047A - 000 - Open Circuit - Intermittent - MIL ON
Freeze Frame:
Fault Status: 10100000
Fault Priority: 2
Fault Frequency: 9
Reset counter: 255
Mileage: 118831 km
Time Indication: 0
Freeze Frame:
RPM: 0 /min
Speed: 0.0 km/h
Temperature: 8.1°C
Temperature: 82.8°C
Temperature: 66.0°C
Pressure: 0 mbar
Pressure: 0 mbar
Readiness: 1 1 0 0 0

Just talked to VW Care, per her talk with dealership: they can't even take me in tomorrow...and are defending that Oxygen Sensor did need replacing...(not believing it)...and say they need to diagnose themselves bc they can;t go by "outside research..."...

Must admit, was ready to jump in but after looking at sensors earlier today, feeling a bit intimidated by tightness of space and trickiness of this one bc it's backwards....felt comfier at thought of doing # 33 in diagram...now not so sure... :-(

 

[mdl3r1]

PS. Any videos out there at all on how to do these?

 

[meerschm]

if it makes you feel better, I managed to snap the plastic retainer clip on the electrical connector, so now mine is held in place with a couple tie-wraps.

it is a little tight, but not the end of the world. back of my legs got a little stiff from that bending over and fussing with it.

if you look around the VCDS screens, the available operation for exhaust pressure sensor adaptation is identified as for the 450, which is the sensor which measures DPF pressure (aka pressure sensor 1, I think)

 

[mdl3r1]

Hey Mike,

Actually, it does make me feel a little better...it one doesn't have to get it perfect to work; after all, it's a machine, not a baby

But question remains: is this one, behind the oil fill, the one that needs adapting or does not?

 

[meerschm]

the one behind the oil fill is not the one the adaptation is for. (on the 09)

the one behind the oil fill is also one which a member (also with an 09) stopped by for a scan, having changed his out, and no reset, (a few hundred miles previous, and no issues)

I actually ran the adaptation, but it messed with the DPF pressure difference readings until the car re-adapted over a few start/stop cycles.

( I never saw any measured soot indicated for a DPF regen cycle or two)

Then I paid closer attention, and saw the pull down menu says it is for the 450 sensor.

http://www.natef.org/NATEF/media/NATEFMedia/VW Files/2-0-TDI-SSP.pdf page 58 diagram backs up the identification of G450 as pressure sensor 1. (and connected across the DPF, not the LP EGR)

 

[meerschm]

and also, here is the legend for that figure I posted (probably should have posted it before)

1 - Exhaust Pressure Sensor 2 -G451-
¤ Located near oil filler neck
8 - Heated Oxygen Sensor (HO2S) -G39-

12 - Exhaust Gas Temperature (EGT) Sensor 4 -G648-

15 - To Exhaust Flap Control Module -J883-

16 - Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130-

17 - NOx Reduction Catalytic Converter

22 - Exhaust Gas Temperature (EGT) Sensor 2 -G448-

23 - Exhaust Gas Temperature (EGT) Sensor 3 -G495-

33 - Exhaust Pressure Sensor 1 -G450-

¤ Bolted to auxiliary fuel pump -V393 - bracket​

 

[meerschm]

http://pics.tdiclub.com/showphoto.php?photo=116396&nocache=1

I put the legend under the figure

 

[mdl3r1]

Awesome! That does clarify.
Thanks again...ordering aftermarket Sensor...and will get tools and give it a go...

 

[meerschm]

the sensor I used was from an online dealer, so an OEM one. was $77 plus shipping.

I used some of the VW goodwill card to pay for it.

 

[Ricosuave]

I also just got the following code:

Saturday,01,October,2016,11:59:27:21461
VCDS Version: Release 805.0

Address 01: Engine
Control Module Part Number: 03L 906 022 PC
Component and/or Version: R4 2,0L EDC G000SG 4029
Software Coding: 0350072
Work Shop Code: WSC 44443
1 Fault Found:

001146 - Can't Decode, CODE File Not Loaded!
P047A - 000 - Can't Decode, CODE File Not Loaded!
Freeze Frame:
Fault Status: 01100000
Fault Priority: 2
Fault Frequency: 1
Mileage: 214719 km
Time Indication: 0
Date: 2000.00.00
Time: 12:49:52

I believe that this sensor is the one by the passenger side strut, not the one behind the oil fill cap.

Unfortunately, I only have the 805.0 version of VCDS (I came from the MK3 and MK4 world), not the newer ones that show "Advanced Coding" and any drop down menus when I try to readapt it.

Does anyone know of the proper coding that I can use with my software?

 

[meerschm]

since you have the same car I do, 2009 JSW, I would guess that the correct sensor for the P047a error code is same as on my car. (one behind the oil fill)


this one does not need any adaptation.

( I do not think you have to adapt the other one either, unless you are in a hurry., but what do I know...)

 

[Ricosuave]

Does anyone know the proper coding to recalibrate the sensors using VCDS 805.0

 

[meerschm]

not sure you can substitute coding for basic settings. ( I suspect the folks at ross-tech would give you a better answer)

why do you think it is the sensor by the intermediate fuel pump (closer to the strut)?

on my 2009 jsw, I had this error:

001146 - Exhaust Pressure Sensor 2
P047A - 000 - Open Circuit - Intermittent - MIL ON
Freeze Frame:
Fault Status: 10100000
Fault Priority: 2
Fault Frequency: 6
Reset counter: 255
Mileage: 257533 km
Time Indication: 0

Freeze Frame:
RPM: 0 /min
Speed: 0.0 km/h
Temperature: 1.8°C
Temperature: 64.8°C
Temperature: 48.0°C
Pressure: 0 mbar
Pressure: 3 mbar


Readiness: 1 1 0 0 0

EPS2 is the G451 as listed in the parts list
http://pics.tdiclub.com/showphoto.php?photo=116396&nocache=1

one additional hint is that the EPS2 measures pressure drop across the low pressure EGR tube.

the EPS1 G450 measures pressure drop across the DPF.

There is an adaptation for the G450 under basic settings, but not for the G451

 

[Ricosuave]

Yes, I got the two mixed up. I changed the one behind the oil filler cap and cleared the error and all is well.

Looks like I should upgrade to a newer version of Vcds.

 

[meerschm]

Thanks for the update.

if you plan to keep the '09 or get another VW, a current VCDS is a great tool to have.