DPF Sensor

[merchant]

Hi all,

I'm currently in a battle with Nissan over this DPF thing. To cut a long story short, my two month old Nissan died in the outback of northern WA. The problem was traced back to the DPF after being at a repairers for six days. When the Nissan warranty dept got wind of this they quickly informed me it was not a manufacturing fault and therefore wouldn't cover the repairs. I was livid.

As a result i started researching what this DPF thing did. This is my understanding; the DPF has three sensors. One prior, on and after the DPF. The sensors measure the pressure differential between each sensor which informs the ECM to increase the fuel delivery which is supposed to increase the exhaust temperature. The increase in temperature burns the soot collected in the DPF, which is supposed to lower carbon emissions and save the world. Apparently, its a European thing.

After two letters and numerous phone calls Nissan have washed their hands of it. The WA dept of trading is now on there heals.

Sorry for hijacking the thread, but i'm a bitter man.

 

[Old.Tony]

Nissan are, admittedly, in a tight corner on the DPF issue, not sure who created it, but when the DPF was invented and they proved that a diesel could have ultra-low emissions, I'm sure the regulators took a look at this potential bonus (as well as the tree-huggers in Nissan HQ*) and decided that it was the way of the future and started a push to have these on all diesels where possible. It's something we are probably going to have to live with as time goes on, and truth be told, I don't really mind.

It will come down to management and maintenance. If the soot in my DPF won't burn properly until I'm doing 80km/h (still under 2,000rpm) then I'll just take off a little harder and let the engine rev to 2500rpm as I accelerate in traffic. That DPF won't operate based on vehicle speed, but on exhaust temperature and flow, and if I am in first gear, I can get that same flow at 20km/h if I wanted.

Nissan may be aware of this - actually, I'd bet my left one that they are - and the entire reason for their reluctance in dealing with this is based on the premise that if you drive the thing a fraction harder, providing the necessary flow through the DPF, it'll never block up and won't give you any grief at all.

The problem I have with that premise is that you might be driving it in the requisite fashion, but there's a variance in the engine/DPF's tolerances and the system hasn't allowed for that. It's possible that your engine naturally runs with a slightly cooler EGT because of a variance in the mixture. I don't know for sure, but at a guess I'd say it's really nobody's actual fault, but Nissan should have acknowledged that their new technology (perhaps only new for the Navara range, it's at least not a commonly seen thing) may have some quirks in it and in the best interests of promoting goodwill for its customers, potential customers and keeping the earth greener (ie promoting the idea that the DPF ought to remain in the vehicle), they should have coughed on this one and taken the information back to their engineers with a view to catering for these sorts of problems.

And hopefully not with the crazy idea of opening the injectors in the exhaust stroke to increase the heat in the DPF. What I would have done is cause the system to kick down a gear, forcing the RPM a little higher while the DPF recovered.

I hope Fair Trading can help turn Nissan around. I think the DPF idea is a good one for the planet, but in its infancy (in this environment) it's something that they need to bend a little more than usual on.

It's just sad that they're trying to play the avoidance game simply because there may have been some means of the problem not occurring at all by driving differently, and ignoring the aforementioned variances in each of our vehicles that provide us with a slightly different feel and prompt us to discuss what mileage we each get etc.

I hope you succeed. I hope you find a way to defeat the DPF problem and really, if it ends up in removal of it because for your vehicle it's just not going to work, then so be it, as long as Nissan acknowledge it and come to the party. They are obliged to make good the vehicle when it fails due to some event that was caused by the manufacture or the design of the vehicle or its components, and from what you've described, that's precisely what's happened here.

* Don't get me wrong - I'm a big supporter of green solutions. Its just more amusing to say it this way

 

[Jason]

Why do only the STX auto's have them?

Why didn't the D22 get a DPF when the 2.5 came across to it?

 

[Old.Tony]

I'm guessing - but probably because they expect the D22s to be worked harder, with the STX aimed at a different audience - people like me, who want a car-like ride that won't be running it waist-deep through mud or trying to climb Uluru. I think they're using us - with lower demands on horsepower - to test the water with the DPF, with a view to eventually fitting it to all other models.

It just makes sense to introduce it to the range where it can be tested without affecting too many sales in the larger market - the work/offroad vehicle market. They'd have the sales figures and know the demographics.

As I said, it's a guess, but its also why I really think Nissan should pay particular attention to these sort of issues and rectify them. They are, after all, the ones trying to introduce the technology. We're just driving the things and flashing their logo at everyone.

 

[burgo]

Old Tony
You'r probably correct but it hurts to be the guinea-pig and foot their experimental bill.
I also suspect Nissan has fudged the fuel test (81/01) as no-one has seen a copy of the documents not even DOT. (I made the enquiry). Some people are using Scangauges to do fuel tests but this may not be accurate, fuel used over distance travelled is the only way.
Good luck with the retuning.
Nissan claim these new ECM can't be remapped but somehow mannaged to do this for the "air bag" recall ??? Looks to me they will only do something when the authority holds a gun on them and MAKES EM.
I suppose the authorities don't like dealing with them either.
Rd's

 

[Bosshog]

As I understand it Mitsubishi dumped the use of the DPF on their diesels for the reasons we're all discussing. Nissan should at least do the same until the technology is refined.

On another matter if we colloborated and put a united position to Nissan they may listen? Just a thought.

 

[JPMC]

Old Tony

Nissan claim these new ECM can't be remapped but somehow mannaged to do this for the "air bag" recall ??? Looks to me they will only do something when the authority holds a gun on them and MAKES EM.
Rd's

The guy's in Europe are remapping there D40's with good results for both economy and power. The only trick is you need a certin type of programer to do it. Not just the normal open type most ECU's use.

Maybe Nissan car makers need to take a leaf out of their truck building cousins. The trucks used to use EGR tech (which the Nav's also use) but lost to much power becuase of it. The new trucks out this year now use the Ablue aditive which means EGR stuff can be removed making engine breath better and produce less emissions and more power out of the same motor. (they went from 450 horsepower to 470)

 

[burgo]

you're right about Mitsubishi and they leave Nissan for dead in fuel consumption.
I asked Nissan about remapping ecm and/or removal of DPF, Nissan declined say they couldn't do it and if it was done warranty would be void.
They don't want to do ANYTHING.
DON'T buy their cars in future is the long term answer.
I'll have a go at any further action.
Rd's

 

[Pete22]

What a bunch of whiners! DPF technology has been around for donkeys ages but until recently has largely only been used on large diesel trucks in the US. There is a lot of information available on the web but a more succinct explanation is here: Diesel particulate filter - Wikipedia, the free encyclopedia

Most of the problems people are having are due to not reading the vehicle handbook. You cannot run for excessive distances at ultra low speeds/revs as the filter cannot do its normal burn function. My DPF light came on after a day of under 24kph on the Gary Highway/Canning Stock Route recently....locked her is 2nd low range....got the revs up to 1800rpm and the DPF regen was done in about 10 minutes of driving. If you keep driving without doing the regen (and the light will only come on after excessive driving at low speeds/rpm) then you will need to get a dealer to do the job and this will cost you. Not a Nissan problem really but one for you to keep an eye on. Mitsubshi still have a DPF (they just call is a catalytic converter in their diesels). It's the way of the future people - and one that all vehicles built to Euro 5 or better standards must comply with - don't matter what we in Australia think the market here is far too small to get a special fitout.

 

[Old.Tony]

Most of the problems people are having are due to not reading the vehicle handbook.

I can't disagree with that. My handbook (which I'd read cover to cover before I'd put 50km on the car) told me to travel above 80km/h to clear the DPF.

That's not always possible, so I figured it's anything above about 1650rpm or so - so around town, I can pull the auto back to third and achieve the same results.

Still begs the question why it's on the D40 autos and not the others, and why they don't make a bit more of a point about it in the manual and in the delivery process since it's so vital to the continued smooth operation of the vehicle.

Not everyone reads the book! I suppose that becomes a valuable lesson for them in the future, when the bill to manually clean the DPF is handed to them.

 

[KraftyPg]

I would reckon the reason they don't make too much of a point in the delivery process could have something to do with the issue not effecting every vehicle. If they put it in the book they expect you to read it and if you don't then it's you're problem. If you read the book then ask them the question even if they don't know the answer they will eventually find out something for you and you can chose whether to believe it or not.

Nav's aren't the only vehicle with DPF sensors and it would ridiculous to say that every engine with a DPF sensor is going to have an issue, or that every owner will notice the DPF clearing itself. So I'd imagine that until every vehicle is having the issue it wont become a talking point at the sales table.

 

[burgo]

Pete22
I think you've missed the point.
Most people complaining about fuel consumption DON'T HAVE THE DPF LIGHT ON
and have a legitimate fuel complaint confirmed by many tests.
Research confirms the problems industry has had trying to contain PM (particulate matter) in USA and Europe and the various methods employed. A lot of us know this already and why there is a need for it.
Mitsubishi are now using a "FREE flow" DPF without the sensors of the previous model. WHY is that??
A CAT is different to a DPF the former converts HC's, Co and Nox. the latter traps particles.
There has been some attempt to combine the two.
Back to reality, the FACT is the D40 Auto YD25 doesn't get the advertised fuel figures, if they did there wouldn't be as many complaints.
Ask yourself "Why aren't petrol D40's featuring higher on the fuel complaints list". It's because the advertised figure, even though much higher than the diesel, is realistic and obtainable.
Having watched certain sensors, PM burn-off can happen quite rapidly in these motors so is not the main problem as you suggest.
Maybe Nissan is trying to get too much out of a 2.5 l diesel fitted with a CAT DPF and EGR and others??
It's about time Nissan fixed their F/Up.
Rd's

 

[KraftyPg]

Pete22

Back to reality, the FACT is the D40 Auto YD25 doesn't get the advertised fuel figures, if they did there wouldn't be as many complaints.

I'm not interested in starting a fight but you're so called FACT is in FACT not FACT! My D40 Auto YD25 gets better than Nissan quote as their combined on the highway and not far off the same combined figure in the burbs and I'm not complaining about it.

It's about time Nissan fixed their F/Up.

If their F/Up is me getting as low as 9.8 lph then I say let them F/Up some more.

 

[burgo]

Krafty,
Glad to hear you're happy
I notice yours is 09 mine is 07
You are stating you Highway figures against the Average so in reality you should get less than the average.
Even lower than the "extra urban" figures should be achievable in controlled "economy trips"
The STANDARD does not represent an 'Economy drive" but more realistic driving of the average person.
Do you take your figures from the scangauge or by calculation?
Rd's

 

[KraftyPg]

Scangauge average is always going to be grossly inaccurate and should only be used as a guide not as a definitive figure and if you understand how the figure is achieved you can see this.

I calculate my figures the old fashion way, liters used against kilometers traveled it's the only way to do it. Also like a scangauge my figures are an average, just that mine are an average based on the amount of fuel used between fills.

I'll never throw my scanguage away and will probably always have some form of fuel reading on it but I'll also be taking into account how it calculates it's figure not just thinking it's right.

I agree that all manufactures don't use real world conditions to test their fuel economy but then it wouldn't be fair to them if they did considering one car can be tested in a high wind and another could have no wind but that doesn't mean you can't achieve those figures. To me it just shows that all manufactures are using the same flawed mathematics.

 

[Old.Tony]

And show me one company anywhere making any product that didn't try to put that product out in the best possible light.

Did you ever get a big mac that looked like the one on TV or the billboard? How about a grand angus? Did your Pizza Hut pizza have the pepperoni perfectly laid out? Did you ever see Clearasil completely remove all signs of pimples or get hair that shines and bounces just like it does on TV?

I am still of the opinion that our cars might be capable of better fuel economy, but minor variances in tolerances (from manufacture, to wear, to tuning and driving) all add up to quite remarkable differences in practice.

I think it makes for interesting discussion, determining how to get an extra half-litre drop per hundred km, and discussing the merits and pitfalls of things like the DPF is a great thing to do because while some of us might think it's the cause of some drop in economy or performance, others may balance that with how much environmental benefit is obtained.

And those looking on will all see, and many will learn.

How many people are reading this thread and thinking to themselves "Great, next time that light comes on I'll sit on 2,000rpm for a bit"? We'll never know. There are guests that can read this forum and I hope they take away some of the more constructive parts here and enjoy the less-than-constructive elements as a "path to enlightenment".

Because that's what all of this is for a great many of us - a new thing (or three) to learn. I know I've benefited greatly from being involved here, and would just like to thank every single participant for helping out in that.

 

[JPMC]

And show me one
I think it makes for interesting discussion, determining how to get an extra half-litre drop per hundred km, and discussing the merits and pitfalls of things like the DPF is a great thing to do because while some of us might think it's the cause of some drop in economy or performance, others may balance that with how much environmental benefit is obtained.

I still don't understand how using more fuel to be better for the enviroment works.
My old Euro 3 spec D40 Auto was more econominal than my Euro 4 spec auto by nearly 100km per tank. My driving habbits haven't changed the only thing that has is the emission control on the Nav. (different EGR and a DPF).
So to me being more environmentally friendly is being cancelled out by using more diesel.
Having removed the DPF my economy has emproved but still not to the same as my old 06 euro 3 spec motor but still better than nothing.

Just my two cents

 

[KraftyPg]

That just makes the DPF like every other useless environmental item. CFL's cost more to make and have crap inside them that isn't all that good for human contact or the landfill they end up in but some wanker has been able to convince the government they are the best thing ever so we all should have them. Is there anything in this world classified as environmentally friendly that is actually saving us money?

If my DPF ever causes me the trouble so many here say its causing them I'm really going to be pissed, the cue waiting to have their Nav's fixed at my local is probably already a mile long and I'll have to get on the end of it.

 

[Pete22]

I'm not interested in starting a fight but you're so called FACT is in FACT not FACT! My D40 Auto YD25 gets better than Nissan quote as their combined on the highway and not far off the same combined figure in the burbs and I'm not complaining about it.



If their F/Up is me getting as low as 9.8 lph then I say let them F/Up some more.

Well I don't get anywhere near 9.8lph but my truck is getting decidely weighty with all the bling and stuff I've fitted. I have just clocked up 35000km and recently did an ecm reset following a filter change - now getting (noting I've only run one tank of juice ie 160ltr) 11.5lph whereas as up until now I've been averaging around 13 to 13.5.

 

[KraftyPg]

I'm not carrying heaps of extra weight around with me on a daily basis, my canopy is a bit heavier than the average canopy and other wise its only tools, and a dual battery so my weight is lighter than yours but I doubt that's the main difference.

As previously stated I'm in the country and while a lot of our roads are still 60 around town we do have less traffic lights and stop signs which make a difference but still not heaps.

While all our cars that are the same models are different those small differences in the car, the driver and the conditions obviously make a big difference in the end.