P2002 particulate filter efficiency below threshold

[NZ XR6]

This is the DTC for the check engine light. There are 2 errors, one confirmed and one pending.

I expect there is more info once I get Forscan running.

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[NZ XR6]

The Check Engine light went off before I was able to install Forscan. I found that there had been a successful regen 4 km previously, which would have near the end of a motorway run. It did sound as though it was doing a regen as I exited the motorway, but was back to normal within a few hundred metres.

So the DP across the DPF was low and varied from 0 to 0.4. kPa while driving. ADBR was 635 km, there were no failed regens and NORFARD was 3. I'm not sure what that one means though?

I suppose all I can do is watch the DP until it does a regen. Any other PID's I should monitor?

[NZ XR6]

A search returned some interesting info. It seems P2002 on a Mondeo usually indicates a fault with the DPF differential pressure sensor, often the hoses from the DPF to the pressure transducer.

Anyone had this problem?


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[whitelion65]

No, but following with interest.

[NZ XR6]

I haven't travelled far in the Mondeo in the last month, but have been checking the PID's regularly. The Check Engine light has gone on and off about every week to 10 days.

The DP reading fluctuates wildly, even when the engine is under a steady load. It has increased gradually since the last regen about 700 km ago, and today reached the maximum of 2 while climbing up the Bombay Hills south of Auckland at 110 km/h. After about 30 seconds, it started a regen.

This completed successfully and the DP dropped to about 0 - 0.4 after maybe a minute? I could not feel any difference in performance after the regen; maybe it lost a little power while it was happening, but difficult to tell.

Some questions:

1) Is 700 km further than usual between regens?

2) How does the ECU decide when to regen, and how long to keep it going?

The DTC description suggests that P2002 is due to either no DPF or damaged hoses to the DP sensor. I am unsure why the CEL cycles on and off, it might be something to do with whether I am driving mainly in the city or trips out of Auckland.

I expect that the next step is it get under the car and check the hoses. I might change the oil at the same time as it is almost due.

[rondeo]

"The DP reading fluctuates wildly"

Sensor or sensor wiring faulty?

"Is 700 km further than usual between regens"

Depends on driving conditions. 300 + I'd say.

"How does the ECU decide when to regen, and how long to keep it going?"

I guess it is based on DPF_SOOT and DPF_LOAD.



DPF_SOOT is a calculated value based on various engine operating parameters.



DPF_LOAD is inferred from the differential pressure measured across the filter.


I guess the time taken will depend on how long it takes for filter temp to reach 600 degrees and on the measured differential pressure.


Check the hoses and the sensor. To check the sensor I guess you'd use a DVM and a hand operated vacuum pump. Or get another from a wrecker which is what I did to carry as a spare.


You also play around with it and learn how to test it.


I'd say the wiring is more likley to give an intermittent fault though, not sure.

[rondeo]

For info on the sensor:


http://www.enginesens.com/Delta-P_60...nstruction.pdf

[NZ XR6]

Originally Posted by rondeo

For info on the sensor:


http://www.enginesens.com/Delta-P_60...nstruction.pdf

Thanks very much for this, very interesting.

[NZ XR6]

Originally Posted by rondeo

"The DP reading fluctuates wildly"

Sensor or sensor wiring faulty?

"Is 700 km further than usual between regens"

Depends on driving conditions. 300 + I'd say.

"How does the ECU decide when to regen, and how long to keep it going?"

I guess it is based on DPF_SOOT and DPF_LOAD.



DPF_SOOT is a calculated value based on various engine operating parameters.



DPF_LOAD is inferred from the differential pressure measured across the filter.


I guess the time taken will depend on how long it takes for filter temp to reach 600 degrees and on the measured differential pressure.


Check the hoses and the sensor. To check the sensor I guess you'd use a DVM and a hand operated vacuum pump. Or get another from a wrecker which is what I did to carry as a spare.


You also play around with it and learn how to test it.


I'd say the wiring is more likely to give an intermittent fault though, not sure.

Thank you. "wildly" may have been overstating it. I am using the Dashboard display in Forscan Lite, and because the increments are quite wide, the needle on the gauge really jumps around sometimes.

DPF_SOOT and DPF_LOAD are not showing in Forscan, so the only PID relating to the DPF is DP. I would really like to see what SOOT is doing to have some understanding of why the CEL is coming on. I might try using Forscan on the laptop to see if more PID's show up.

At first I thought it was the hoses, as the first info I saw in Forscan was a few km after a regen and showed low DP readings. But it appears that the DP sensor is working because the readings increased, and then went back to zero after the regen.

Time to have a look under the car. At least it is running well and the fuel consumption is normal, so it appears whatever is causing the CEL to come on is not serious.

[NZ XR6]

The light has been on constantly for the last week. The DP reading is always zero now, so definitely the DP sensor or hoses.

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[Crazy Dazz]

I never even realised they had a DPF, but guess it makes sense.

What does it actually do when it regenerates? I'm guessing it burns the soot, but how?

I've read that if the DPF gets too badly clogged, the computer will not initiate regeneration, to avoid potential damage?

Are these easy problems to fix?

Reason I'm asking is that I've been looking at a cheap old Mondeo (2010) that is known to have a DPF problem. (Engine light on, and codes indicate that the DPF won't regenerate.)

[simon varley]

Originally Posted by Crazy Dazz

What does it actually do when it regenerates? I'm guessing it burns the soot, but how?

I didn't think Mondeo had a DPF either, but if it does, there are a number of things it can do to burn off the soot

• Natural Burn.
  under moderate to heavy driving conditions the natural temperature of the exhaust gasses is high enough to start combustion of the soot trapped in the filter. This is the 'normal' method and for most people all that is really needed
• Controlled Burn
  under certain circumstances the car PCM may decide it needs to initiate a burn itself. This can be triggered by a number of things - pressure drop too high, time since last regen, distance since last regen etc. this would be why OP reports a failure due to pressure sensor issues. There are a number of ways the car can do this, and I'm not sure what Mondeo actually does. It can be achieved by artificially raising the exhaust temp up to where it combusts the soot. Some cars have an extra diesel injector to pump in a small amount of fuel just before the DPF to ignite it.
• Dealer Burn
  when all else fails the dealer can plug in an initiate a Service action to burn off the soot. This is rarely needed, and to be honest is a bit risky. the temperatures generated in a burn are really high, and without a lot of airflow over the exhaust, it can get very, very hot around it.

at some point though, even with all of this, the DPF will get to a point where it is full up. the burn leaves an ash behind and that just builds until the only solution is to replace the dpf with a new one

[rondeo]

'Natural burn' There is a catalyst (platinum) which enables a burn of carbon at a lower temperature than would normally be required. It is continuous at normal operating temp.

'Controlled burn' happens frequently (every 300km or so depending),
with injection of vapourised diesel ahead of the DPF, because the catalytic effect is insufficient.

'Dealer burn' temperatue is no higher than normal regeneration, which is around 600 degrees C. It normally happens frequently at a standstill and is quite noticeable with thumping noises and changed exhaust note.

My car has done 280 000 km and the differential pressure has hardly changed since new, but yes, ash is accumulating. Depending on the oil etc.

[whitelion65]

I’ve just tried Liquimoly DPF clean addictive.
One tank through, but too early to tell if it’s worthwhile. I’ve lost my scan tool, so can’t monitor regens, but AT LEAST one happened last tankful.
About to take a road trip, so will report back.

[Crazy Dazz]

Thanks guys
This is a high mileage model, around 290kk. So assuming its never been done, it's probably due for a new DPF.
Given the overall high mileage, I think we'll give it a miss.

[NZ XR6]

They can be removed and cleaned, either thermally or using a steam cleaner. You would have to check pricing where you live, but it shouldn't be too expensive.

[NZ XR6]

A follow up to my original post. I found that the regens continued happening, but at more frequent intervals, which I expect is a failsafe programmed into the ECU. If anything, the engine runs better with the more frequent regens, and I check for new PIDs with Forscan regularly.

Normally, I would have sorted this far more quickly. But there has been a lot going on during the last 6 months...

[simon varley]

as the DPF ages, and starts to fill with ash, there is naturally less and less volume to filter the soot, so you'd expect it to fill quicker and quicker as time goes by

[NZ XR6]

A follow-up to my previous post. I recently travelled to Taranaki and back from Auckland. Passing opportunities in parts of the road are limited, and in places you need a car with good acceleration to overtake safely.

The MB sometimes felt a little breathless at higher revs and I have always been careful to allow plenty of room when overtaking. But now it pulls hard until the upshift and I found myself going faster than expected after passing long trucks.

Fuel consumption has improved slightly also. The average after about 1,000 km was 6.1 l/100 km, which is better than I expected for the mix of driving during the trip.

I really should repair the differential pressure gauge as it's not good to have the check engine light stay on. But it isn't often an engine runs better after developing a fault!

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[msford]

I have a Mondeo Titanium MC 2011 Hatch and I began receiving this engine malfunction error in July (2023) and have since been told it's the P2002 error. I've had a local mechanic make several attempts to fix it including a forced regeneration of the DPF but the error still occurs.

Whilst most of my daily driving is Melbourne city gridlock (eg Hoddle St) I have also done several Hume Fwy drives to NSW (about 850km each way) and the error comes up whilst I'm cruising at 110 kph. I've also noticed it often occurs whilst going on an incline. On the latest Hume Fwy trip it happened at least half a dozen times. And it also occurs when in cruise control or regular acceleration, but it has also occurred going at 50-60kph on a suburban street.

It's at the dealer today in the hope of finding a solution as I don't really feel comfortable with that warning when I'm on a freeway going 110kph and nowhere near a mechanic, especially on a Sunday of a long weekend.

[goz007]

There are places that can now Wash & sonic clean dpfs to as new condition & it's not that expensive(no were near what a new dpf is worth)

[msford]

Originally Posted by goz007

There are places that can now Wash & sonic clean dpfs to as new condition & it's not that expensive(no were near what a new dpf is worth)

Hi, I'm interested in this. Can you tell me where you've seen this and do you have a recommendation (I'm in Melbourne).

Thanks in advance.

[goz007]

https://youtu.be/LZsomk41WJo?si=PjxpVFy_T9irL1P1

[goz007]

Sorry not familiar with anyone in Melbourne who does it(I'm in Sydney) but I'm positive there would be places in Melbourne who do it.

[manchu]

Originally Posted by msford

.. P2002 error. ...

It's at the dealer today in the hope of finding a solution

What did they say?

I had a P2002 error with my 2017 isuzu mux recently and turned out to be the pressure sensor, and not the DPF itself. Fairly common issue with that vehicle apparently and lucky for me the $1500 fix was done for free out of warranty.

Easy to tell if you have a OBD scanner and watch the pressure signal. If it's stuck at a constant value regardless of what the engine is doing it's a sensor problem. When I cleared the fault it'd return almost instantly and go back into limp mode.

I think yours is probably a clogged up DPF though.

[msford]

Originally Posted by manchu

What did they say?

I had a P2002 error with my 2017 isuzu mux recently and turned out to be the pressure sensor, and not the DPF itself. Fairly common issue with that vehicle apparently and lucky for me the $1500 fix was done for free out of warranty.

Easy to tell if you have a OBD scanner and watch the pressure signal. If it's stuck at a constant value regardless of what the engine is doing it's a sensor problem. When I cleared the fault it'd return almost instantly and go back into limp mode.

I think yours is probably a clogged up DPF though.

They replaced the sensor and for a few weeks of city driving I didn't get the error but on my first freeway outing and driving at 110kph it came up. And continued to appear multiple times on the same trip, plus on the return (just today). Plus it has also occasionally come up during suburban drives at much lower speeds. So, it seems, I wasted my money on replacing the sensor.

I'm back to square one of not having the faintest idea of what the fix is, though that post prior about cleaning the DPF cheaply appeals.

Though I have to say that I'm not keen on spending more money replacing other parts that may not solve the problem. I'd willingly pay for the right fix, but the impression I'm getting from several mechanics I have asked and tried is that they will keep 'guessing' until they get it right and those 'guesses' will be at my expense. It's hard to find a mechanic that has actually dealt with this specific problem.

So, barring someone with the knowledge to work it out on their first go, I'm stuck with driving with the error code. From the research I have done, according to some 'experts' online it is an error that can be 'ignored'. The engine will run mostly fine but it will have its issues mainly when driving on an incline and it doesn't have the grunt to continue going at 110kph and it slows down 10-20kph depending on the level of incline. At least, that's my experience driving on the Hume Fwy.

Cheers

[manchu]

Originally Posted by msford

So, it seems, I wasted my money on replacing the sensor.
Cheers

That's disappointing. I'm no expert buy as I said I reckon it's pretty damn obvious when you've got a faulty sensor so they shouldn't just be throwing parts at it without due consideration, but I suspect that's exactly what's happened.

Originally Posted by msford

according to some 'experts' online it is an error that can be 'ignored'. The engine will run mostly fine but it will have its issues mainly when driving on an incline and it doesn't have the grunt to continue going at 110kph and it slows down 10-20kph depending on the level of incline. At least, that's my experience driving on the Hume Fwy.

So the car goes into limp mode when the error is active?

That's what my isuzu did and while it was still drivable I don't think it's a good idea at all so kept it to bare minimum until it was fixed. It's just unsafe if you don't have the power you usually expect.

[msford]

Originally Posted by manchu

That's disappointing. I'm no expert buy as I said I reckon it's pretty damn obvious when you've got a faulty sensor so they shouldn't just be throwing parts at it without due consideration, but I suspect that's exactly what's happened.

I'm changing dealers after the past few services. It has changed ownership several times and I'm becoming less satisfied with each subsequent dealing with them.

I have had several bad recommendations from them recently to change parts that they said needed changing. In one instance they wanted to replace something that was going to set me back well over $1k yet it was totally unassociated with the problem and I ended up fixing the actual problem myself after some YouTube tutorials.

So, it wouldn't surprise me if the sensor wasn't the real issue. They wanted to replace another part, as well (nothing to do with the DPF) but I said No to that. I've lost trust in them.

It will mean I'll have to travel further for another dealer but so be it.

Which comes to the point as to why I've reached that decision. After doing some research, over the past few days, on the DPF cleaners I noticed something they all universally mentioned. Before giving them the DPF to clean that I should ensure it wasn't a list of other factors causing the warning. And one of those factors was the correct oil for my diesel engine was used.

Now, the reason I have this 'suspicion' (and it's only a suspicion unless there is a way I can test or verify it) is that all of this engine malfunction issue happened after my last service at that dealer (July this year). And it occurred to me what if they used the wrong oil? I know they shouldn't, but what if they did? Because all the DPF cleaners stated that the wrong oil will cause 'bad' burning and trigger the malfunction warning.

So I'm thinking of getting just an oil change and seeing if that does anything. It's the least expensive, and simplest, test I can do before going down the route of cleaning the DPF.

Originally Posted by manchu

So the car goes into limp mode when the error is active?

That's what my isuzu did and while it was still drivable I don't think it's a good idea at all so kept it to bare minimum until it was fixed. It's just unsafe if you don't have the power you usually expect.

Yes, it goes into limp mode. The only power 'failure' is when going up an incline. At all other times you, honestly, wouldn't even know you're in limp home mode. It feels like it drives just as well as any other time. And, on the most recent trip (1800km round trip) driving at 110kph on the Hume Fwy, my fuel economy was identical to any past, regular trip even though I was driving in limp home mode for almost the entirety of the journey. I always get over 1200kms from a tank, sometimes as much as 1300kms on those Hume Fwy drives.

My car is probably only valued at around $6k-$8k so it's just not worth me spending an enormous amount of money to fix it nor can I realistically sell it with such an error so I may as well drive it until it conks out. That's my thinking, anyway.

[AlanM]

Originally Posted by msford

They replaced the sensor and for a few weeks of city driving I didn't get the error but on my first freeway outing and driving at 110kph it came up. And continued to appear multiple times on the same trip, plus on the return (just today). Plus it has also occasionally come up during suburban drives at much lower speeds. So, it seems, I wasted my money on replacing the sensor.

I'm back to square one of not having the faintest idea of what the fix is, though that post prior about cleaning the DPF cheaply appeals.

Though I have to say that I'm not keen on spending more money replacing other parts that may not solve the problem. I'd willingly pay for the right fix, but the impression I'm getting from several mechanics I have asked and tried is that they will keep 'guessing' until they get it right and those 'guesses' will be at my expense. It's hard to find a mechanic that has actually dealt with this specific problem.

So, barring someone with the knowledge to work it out on their first go, I'm stuck with driving with the error code. From the research I have done, according to some 'experts' online it is an error that can be 'ignored'. The engine will run mostly fine but it will have its issues mainly when driving on an incline and it doesn't have the grunt to continue going at 110kph and it slows down 10-20kph depending on the level of incline. At least, that's my experience driving on the Hume Fwy.

Cheers

It's possible you have a new, different problem! If the car was good for a while after they replaced the sensor something else might have cropped up in the interim.

It really would pay to get an OBD adapter and Forscan. The symptoms you describe are exactly like a faulty MAF sensor, or even a leak downstream from the turbo causing a MAF sensor plausibility alarm. (I've seen both!)

[goz007]

I bought the DPF in the link I listed, paid$250 for it from an MD that had done 122k, I thought it a good buy for the sensors alone(the DPF has 3 sensors mounted to it)