DPF - Pressure Sensor.......

M

mpc

Registered User
Joined
May 20, 2013
Messages
122
Reaction score
6
Points
18
Location
NULL
So the last week I have had problems with my 2.0 TDi S-Line, mainly the yellow emissions light on the dash. I dreaded the DPF saga but took the car in to a local non audi garage who I have used for years. Firstly they cleared the code and ran a forced regen and sent me off to see how i got on. 2 days later the light is back on the dash again (side note, i had noticed the fan was running after turning engine off - not every time but more often). I took car back to garage and they plugged into vagcom, it read that dpf pressure sensor was faulty and glow plug - i got them to replace sensor and all plugs which they did and also ran a forced regen again. Checked for fault codes again and all was clear, I was also told the readings were quite low for the dpf to be blocked - great I think - all sorted. This was the day before yesterday.

This morning after parking up at work I noticed the fan is still running after turning the engine off (a short 4 mile journey), another thing this morning on my drive in was the gear change indicator was showing up at speeds that it normally doesn't - my gut feeling is it's still not sorted and I'm half expecting to get in the car tonight with the emissions light back on the dash - am i worrying about nothing?
 
If one of the EGT sensors are faulty this will cause the ecu to run the fans as a safety measure. I would log all of the temp sensor's both EGT and coolant.

Cheers
 
fan running after turning off tends to be a interupted regen
 
The DPF pressure sensor is a pretty common failure and does cause the kind of issues you have seen. It is possible that the DPF has become pretty blocked up as without the pressure sensor to tell the ECU how much back pressure is being generated by the DPF it's not possible to correctly regenerate it.
You are probably doing most of your trips on short runs which really isn't good for the DPF anyway. You need to take the car for a good run something like 30 miles and at a decent steady speed. A run up the motorway at 70-75 mph would be great. This would give the car a chance to complete a cycle.
As Bobby says it is possible that an EGT has failed but that should have brought up a fault code.
 
But the car has had 2 forced regens since Friday so how would me taking for a good run make any difference?
 
Well as I suspected when i left work tonight the engine emission light was back on the dash! Gutted.
I've rang the garage i had the work done at and they have suggested i take it in the morning and they will run the vagcom on it and see what codes come up. I fear they are just going to suggest getting whatever is says done rather than look into the root of the problem. I've already spent near £400 and its still not resolved.
Don't know what to do for the best with this. Frustrated.....!!
 
If the garage has VAGCOM get the error codes and the following would be useful:
Particle filter: soot mass measured
Particle filter: soot mass calculated
Particle filter: oil ash volume
Particle filter: difference pressure
 
The problem with DPF issues where they haven't been regenerating properly is that there is quite often a large amount of soot /ash that clogs the DPF and is very difficult to clear. A forced regen isn't as good as a proper regen cycle taking place when the car is running on the road. As Bobby says it would be good to know what the ash value is and what kind of back pressure is being seen by the engine.
 
So my car was back at the garage on friday, the error code that came up was the sensor again (this was replaced 2 days before). They cleared the error code and sent me on my way. The engine emissions light came back on yesterday! Car back at the garage today. They seem to be at a loss as to what the fault is?
I did wonder if the new pressure sensor was faulty?
 
Did they do the reset using VCDS after the pressure sensor?
 
Had loads of DPF issues with mine, including faulty (new) pressure sensors, make sure they use the genuine Audi part as I had two new non-Audi ones both fail after around 100 miles.
 
toastyhamster said:
Had loads of DPF issues with mine, including faulty (new) pressure sensors, make sure they use the genuine Audi part as I had two new non-Audi ones both fail after around 100 miles.
Click to expand...

I was told they did use a genuine Audi pressure sensor. I did wonder if it was a faulty one?
 
so the garage have had my car for 2 days and have been onto 'their' technical help team who have advised different methods of clearing the ecu memory as they are not convinced that solely using vagcom has been clearing the error code from the ecu memory.
Anyway it has been left with me taking it tonight in the hope that the engine emission light will not appear back on the dash - if it does, the only other option is for me to take it to Audi as it may be a software issue?
 
update, so the engine emission light came back on the dash again this morning! Been told by garage my only option now is taking it to Audi as the garage don't know what else to do. They suspect it may be a software issue that will need Audi to do.
My issue with this is will I lose the remap that I had done a few years back if Audi update the ECU software? My other concern is will Audi charge me again to change the pressure sensor even tho its already just been done by another garage?
 
Sounds like you need a second opinion, but yes Audi is probably the most expensive option. I can't remember the make of sensor that failed on mine (pro something I think). My symptoms were stuttering at around 1.5-2k rpm, and needing to put foot down to clear, eventually to the poiint my foot would be flat down and nothing would be happening until it all suddenly kicked in - so a progressive failure. No warning light the first time but error code of sensor reading out of range, second time before it got really bad it went into limp mode, but by then it was booked in anyway, garage stumped up for a genuine sensor and it cured it. Ironically they probably should have kept the original sensor but as the DPF was cleaned they change it as a matter of course at the same time.
 
OK so the saga continues!
The engine emission light came back on again within a day so I took it to another garage and have been informed that the pressure sensor that has been fitted to my car has a code of 076906051B - aparantly the correct code that should be fitted to my car is 059906051A.
I now have to take my car back to the original garage and get them to fit the correct sensor and try sort out who is going to foot the bill from the second garage for looking at my car!
Getting there slowly!
 
Well hopefully looks like you will have it sorted soon. Those 2 sensors aren't compatible as the output range is different so the ECU will be seeing completely the wrong values. The first garage should have checked the part before fitting it.
Granted they look the same physically and the pipes will fit but the part number is nothing like the same.
The first garage should be liable for all the costs and replacement of the sensor with the correct part
 
desertstorm said:
Well hopefully looks like you will have it sorted soon. Those 2 sensors aren't compatible as the output range is different so the ECU will be seeing completely the wrong values. The first garage should have checked the part before fitting it.
Granted they look the same physically and the pipes will fit but the part number is nothing like the same.
The first garage should be liable for all the costs and replacement of the sensor with the correct part
Click to expand...

I do know there was a VW golf in the garage the same day having the same sensor fitted, i did wonder if they have got them the wrong way round? Would that code (fitted to mine) fit a VW Golf?

I do wonder how I am going to tackle the issue of the first garage paying the bill of the second one!? I'm no good with conflict!!
 
Yes that sensor fitted to your car fits an A3 / Golf / Tiguan etc. They are a common failure so looks like that could the reason behind the **** up. In which case there is another car driving around with an issue.
 
just get a DPF delete done its problem solved forever. otherwise this fault will come back again and again.
DPF deletes costs roughly 400 quid and the car will run much better and a little faster.
i had the EGR valve deleted at the time and a remap, transformed the car tbh
 
  • Like
Reactions: aphill24
You must log in or register to reply here.

Similar threads

NethanB
DPF Pressure Sensor Calibration
Replies
5
Views
10K
NethanB
NethanB
VrX
Oil pressure sensor
Replies
0
Views
617
VrX
VrX
A
Help Please DPF Pressure tube - How to remove?
Replies
2
Views
684
AudiLeon
A
O
3.0 TDI Exhaust Pressure Sensor
Replies
2
Views
3K
Owyn
O
bonifacy87
16618 Boost pressure sensor issue
Replies
5
Views
3K
bonifacy87
bonifacy87
Top
Back