DPF problem + engine light...

[nowa]

Hi all,

I've been a lazy member, sorry... Obviously as soon as there is a problem I turn to the forums hoping someone might be able to help... please, some advice would really be appreciated...

Here's some background

I just did a very looong trip, 1500km (non-stop, except a refuel) on the autobahn @ speeds of about 170km/h.
This in my A4 2.0TDI (143BHP) and quite heavily loaded.
Arrived fine at my destination and have since then for 3 days been doing some 'slow city driving'
So today, suddenly the DPF icon popped up with a beep on the board computer.
I continued to drive for about 15min, then switched the engine off for a good 2h.
Starting it up again and the DPF icon is longer there, but instead the 'check engine light' has come on and will not go away.
The car is not in 'limp mode' or anything like that, it drives/pulls just normally (so far)

I have a VAG-COM tool and I will read out the fault code(s) tomorrow but I would assume it will have something to do with the DPF.

Is there any point of doing a forced regen? I would have thought that after such a long trip, the DPF would be clean as a whistle?
I have heard that there is a way to see how clogged the DPF is using VAG-COM, and also, I have heard that there is a way to check the sensors using VAG-COM, can anyone help with a procedure?

I have the CAGA engine code, and the car is a 58reg (08/2008) A4 2.0TDI Avant (143BHP) S-line.

Please help... Thanks in advance

[Dasquade]

Well the exact vag error code will help once you have the time to read it.
I'm guessing it is just a faulty sensor...had to replace mine 2-3 weeks ago (not sure but+-80€...?).
Had around 47.000km on it, mostly very short trips.
Could be your code on dashboard is back off tomorrow, anyway in case it is the sensor just replace it and move on :).
Good luck (don't delay it).

[nowa]

Thanks Dasquade, looks like you were right...

This is what the VAG-COM log gave:

-------------------------------------------------------------------------------
Address 01: Engine (J623-CAGA) Labels: 03L-906-022-CAG.clb
Part No SW: 03L 906 022 JM HW: 03L 906 022 B
Component: R4 2,0L EDC H01 3173
Revision: 11H01---
Coding: 0104002C18072118
Shop #: WSC 06335 000 00000
ASAM Dataset: EV_ECM20TDI03L906022JM A01005
ROD: EV_ECM20TDI03L906022JM.rod
VCID: 79FDE9D74949

1 Fault Found:
5262 - Diesel Particle Filter; Differential Pressure Sensor: Short to GND
P2454 00 [168] - Defective
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 2
Mileage: 144213 km
Date: 2013.10.29
Time: 14:17:18

Readiness: 1 1 0 0 0

-------------------------------------------------------------------------------


So... Now I'm wondering... I'm currently in Germany and I have about 1500km to go before I'm back in good old UK... Will something go pop if I drive 1500klicks with this condition?

Also, I knew this wouldn't help for long but I did it anyway... I cleared the error using my VAG-COM tool and of course the 'check engine light' went off but just as I knew, only for about 15min, it is now back... so I assume the fault is genuine.

I don't suppose anyone knows if this sensor is difficult to change on a A4 B8 2.0TDI ?
Does this sensor need any 'adaptation' once replaced and if so, can it be done using VAG-COM ?
I'll start to look for the part myself straight away but again, if anyone would happen to know how much it costs, I'd appreciate any info.

Just one more thing. I'm not a 'power user' of the VAG-COM tool but I did find some "diagnostics" in VAG-COM and I managed to read out the following:
----------------------------------------------------
13:18:35
6 hPa Particle filter; difference pressure 152
00000000 Particle filter; field regeneration lock status 153
0 Particle filter; field regeneration lock status 161
771367 m Particle filter; kilometers since last regeneration 162
49.93 l Particle filter; fuel consumption since last regeneration 163
0.11 l Particle filter; oil ash volume 164
0 hPa Particle filter; offset for differential press. 165
16.40 g Particle filter; soot mass calculated 166
16.17 g Particle filter; soot mass measured 167
41553 s Particle filter; time since last regeneration 168
-------------------------------------------------------------------
Am I understanding this correctly? It seems to me very strange that the tool says that:
- time since last regeneration is 41553s
and
- kilometers since last regeneration is 771367m (I am assuming that this means 771km)

This last statement could very well be true, that the last regeneration took place 771km ago, but that certainly was not 41553s ago.
There is no way that I have done 771km in the past 41553seconds!


I really appreciate all the help and suggestions!

[nowa]

I've done some research now and I know how to do the adaption of the new sensor myself with the VAG-COM. I also know where to get the part from and I could do it all here on location (I'm still not at home) as it really does not seem too difficult to change it myself.
What I haven't been able to find though is where the b----y thing is...

Where is the Differential Pressure Sensor located on a (B8) Audi A4 2.0TDI (143BHP) engine code CAGA ?

Any help?

Many thanks again!

[Dasquade]

If not mistaken that was the same sensor (afaik the dpf has 2 sensors....the pressure sensor beeing the cheapest and easiest to replace).
I forgot how much my shop charged but like said around 80€ including work (half houre i think).
I stayed by the car when he changed it...but got destracted by a customers RS4B8 on the bridge next too me ;).
(just had new exhaust...and owner was friendly enough to show me his beast).
So i didn't followed the swap entirelly...

Personally for that money i would stop by any local or passing audi dealer on the way home. If they have the time, it is taken care off fast.
You do NOT want to drive around without a working sensor (as it will not trigger regeneration anymore).

ON the other hand, 144213km is afaik around the lifespann when most need to replace their DPF :(.
*Maybe time to remove the DPF and eliminate him...still need working sensor and recoding.

Good luck.
*nice find regarding the last regeneration procces. 771km (and +-11 engine running houres?) seams good.

[Dasquade]

Hm, i just took a look. If not mistaken it is the first sensor on the DPF (pipe down low left of the engine).
Like said, two sensors on the dpf...don't quote me but thought it was the one most to the front (thicker wire).
If wanted i can post picture.

[nowa]

Thanks Dasquade!

I really appreciate your help, I am still a bit unsure, but after googling this myself, I think that the sensor that is broken, is the one sometimes referred to as the 'G450 sensor' again, I am not 100% sure, but I think that one my car, that sensor is located as the picture below shows:





Here is also a picture of the actual sensor that is broken, at least that is what I think...



The sensor itself, looks like a small box (size is half of a cigarette pack) with 2 pipes coming down from it (one pipe slightly larger than the other) and in the back is the electrical connector, there is also a hole for a screw that holds the sensor in place, it screws on to the engine.

So I think that I have successfully found it (I hope) but here is where I am a bit confused...

People seem to refer to this sensor as part number 076906051A but after taking mine out, and as you can see on the picture, mine is part number
059906051A.

So, I now wonder, is there another sensor in my car with part# 076906051A (if so, where is it?) and is it that sensor which is broken?
Or, is it just that on my car, the diff. pressure sensor is called part# 059906051A?

[Dasquade]

Hm, short term memory here :p but i'm sure the sensor is located on the left-front side of the engine...at least it was there the mechanic did his job.
Again imho for the price i payed and installtime (just checked: 135€)...
I just checked some more on the dutch audiforum.nl and the sensor on the back of engine is the one that checks the gasses.
I can't find my error code to compair with yours so could be we are talking about different sensors :(.

[Dasquade]

Just searched a bit more: http://www.audizine.com/forum/showth...th-fault-codes
SHORT to GND...did you check yours fuse?

boot (right side) using a multimeter (whitout taking the fuses out) and found one fuse blown. 15A
blue in the Orange/Red fuse carrier. (According to the manual it's "Socket, centre console, rear").

[Dasquade]

As refurring to the partnumbers...correct! The older ones had 059906051A...and are replaced by the newer 076 906 051A ones.
->http://www.audiforum.nl/forum/b8-200...ml#post1436432
(dutch forum sorry).
And apperently that sensor (differental pressure sensor) is indeed on the back like you pointed out (my bad...i blame the rs4 present at that time :))

[ilky]

Hello dear colleagues,

I've received the same DPF error with the MIL on about two weeks ago during my vacation :) Nice gift from my Audi :D . However I managed to buy a VCDS cable interface and determined the below errors and DPF values:

4914 - Diesel Particle Filter Differential Pressure Sensor
P2453 00 [032] - Implausible Signal
5182 - Particulate Trap Bank 1
P2002 00 [096] - Efficiency Below Threshold
Intermittent - Not Confirmed - Tested Since Memory Clear
5262 - Diesel Particle Filter; Differential Pressure Sensor:
P2454 00 [039] - Short to GND
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:000001

Address 01: Engine (03L 906 022 JM)
02:49:27
071 Particle filter; difference pressure -3 hPa
072 Particle filter; field regeneration lock status 0
073 Particle filter; field regeneration request status 0
074 Particle filter; kilometers since last regeneration 482571 m
075 Particle filter; offset for differential press. -12 hPa
076 Particle filter; oil ash volume 0.11 l
077 Particle filter; soot mass calculated 19.73 g
078 Particle filter; soot mass measured 16.22 g
079 Particle filter; time since last regeneration 42617 s

I am looking now for an advice , I doubt that the filter is so dirty to have it cleaned or even replaced, so I should start with sensor, replacement and adaption followed by a drive on a motorway in 5th gear ~120kmh ? Or is it anything else you can highlight?
I would add that after cleaning those errors neither the MIL or error code went back on and that I had 4hPa diff pressure at idle at the beginning and around 18g measured . The above DPF values were gathered after a short 3 km drive.

Any other suggestions? Might also be a bad oil as the oil volume looks weirdly high for me? During regeneration do you know if the oil can be burnt also ( even that I doubt it)?

Thanks!