DPF Sensor
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Hi Jason,
I don't think so as the differential pressure sensor and temperature provide this advice to the EMC (ECU).
At a guess I'd say something to do with the CAT but would like to know for sure. My workshop manual doesn't mention it.
Rd's
Burgo
if its an oxygen sensor (and not an egt sensor) then most likly would tell the ecu that the regen soot filter is working. probably to make sure there is enough oxygen to burn the soot. ie if it reads excessively rich then it would cut back fuel or increase boost to provide enough air for the regen to work.
My understanding of the operation of the DPF is that it doesn't just come on at a particular time, it tries to burn the soot at a higher temperature all the time. It's effectively a catalytic converter for diesels. My manual says that the light operates when a certain amount of particulates are remaining in the filter and that as soon as you are safely able to, you should drive the vehicle at higher than 80km/h.
I wouldn't want to be the Nissan dealer assigned to Venice with THAT in the manual.
There could be several measurements taken in that area. Local temperature for one, to know that the DPF is operational. Pressure on both sides, oxygen level would make sense to take a reading as well.
I'm trying to find it in the workshop manual but I must be going blind - all I can find in the exhaust system is a "CAT" and it doesn't go into any detail about it. Hopefully they don't mean "this is where stray moggies will be moved to while driving".
Something tells me that there's a better workshop manual than the one I have - I am going to try and get my hands on it.
I wouldn't want to be the Nissan dealer assigned to Venice with THAT in the manual.
There could be several measurements taken in that area. Local temperature for one, to know that the DPF is operational. Pressure on both sides, oxygen level would make sense to take a reading as well.
I'm trying to find it in the workshop manual but I must be going blind - all I can find in the exhaust system is a "CAT" and it doesn't go into any detail about it. Hopefully they don't mean "this is where stray moggies will be moved to while driving".
Something tells me that there's a better workshop manual than the one I have - I am going to try and get my hands on it.
you have to get the later manual. i've only got copy of the older one.
the problem some ofthe UK guys where getting was they do so much around town driving the DPF doesn't get hot enough to burn off.
some diesels have a regen mode where it creates hot exhaust (change of fueling/timing even inject fuel on the exhaust stroke)
the problem some ofthe UK guys where getting was they do so much around town driving the DPF doesn't get hot enough to burn off.
some diesels have a regen mode where it creates hot exhaust (change of fueling/timing even inject fuel on the exhaust stroke)
Gents
Thanks for your interest and replys so far
The 2007 TD auto has a pressure differential sensor across the DPF (pipes lead up to the sensor mounted aft of the air filter), also a temperature sensor fore and aft of the DPF.
I haven't been able to get a nissan techo to explain the operation of the O2 sensor?? yet.
Rd's
Burgo
Thanks for your interest and replys so far
The 2007 TD auto has a pressure differential sensor across the DPF (pipes lead up to the sensor mounted aft of the air filter), also a temperature sensor fore and aft of the DPF.
I haven't been able to get a nissan techo to explain the operation of the O2 sensor?? yet.
Rd's
Burgo
got any pics of it ?
Nizzbits
Member
Going by the parts manual on the DPF there are two "ENGINE COOLANT TEMPERATURE SENSOR" (how does that work???) and an "AIR/FUEL RATIO SENSOR".
Separately there is (on the end of the two hoses/pipes a "DPF PRESSURE SENSOR".
Separately there is (on the end of the two hoses/pipes a "DPF PRESSURE SENSOR".
id be interested in knowing how to bypass that sensor..
because once the DPF is removed.. that sensor reads wrong. abd brings up the engine light.. is there a way of trickin the ECU into thinking its still there and everything is good.
because once the DPF is removed.. that sensor reads wrong. abd brings up the engine light.. is there a way of trickin the ECU into thinking its still there and everything is good.
Nizzbits
Member
I am no sparky/mechanic but a guess would be it might be measuring unburnt fuel or in some way rich/lean and telling some box or another to adjust fuel map. Then again it could be just something to put it into limp mode if it is outside a certain parameter.
So much crap on these engines these days. I know a dealer who had a Pathfinder they buggered around with for weeks. It would start perfect, run for 10-40 seconds and then just stop dead. Ended up being timing chain related. Computer could not get the timing right so after 30 seconds just said stuff it lets just chut down and go to sleep.
I can't imagine it would be anything more complicated than a certain resistance range being deemed "good"? Test the resistance across the sensor when the DPF is "good", insert a resistor in place of the sensor to mimic that resistance and see if you get a CEL?
Gents,
Thanks for your interest, here is a site that gives some insight to the generic principles possibly applied
Particulate Filter Regeneration and NOx Catalyst Re-Activation - Patent application
By the sensors and devices fitted to the YD25, this is close
What we need to know is what and when ? Nissan has determined things to happen.
The A/F ratio sensor could be used simply to control over fueling or is it used as a NoX2 sensor to initiate cat. conditioning? (also temp. can be used to assist here as NOX increases so does Temp). This would be used in conjunction with the intake butterfly V/V to create a rich (low O2) environment.
While over-riding some sensors might be simple enough I don't think it prudent to delete the safeguards.
I have seen one of these things go without any exhaust restrictions (cat and DPF) No need for a CHIP they go like a Cut Snake and the economy also improved considerably.
I believe NISSAN have some problems with the mapping of these vehicles as the economy is inconsistent with output.
JABBA,
In another arena I have seen it suggested the Scan-gauge may be having an effect on the ECM that somehow improves economy. What's your thoughts here? (did you fit it about the time of fuel improvement?)
It was also suggested that this wouldn't be the case as the gauge only READS information, however in the field of electronics strange things have been known to happen.
Rd's
Burgo
Thanks for your interest, here is a site that gives some insight to the generic principles possibly applied
Particulate Filter Regeneration and NOx Catalyst Re-Activation - Patent application
By the sensors and devices fitted to the YD25, this is close
What we need to know is what and when ? Nissan has determined things to happen.
The A/F ratio sensor could be used simply to control over fueling or is it used as a NoX2 sensor to initiate cat. conditioning? (also temp. can be used to assist here as NOX increases so does Temp). This would be used in conjunction with the intake butterfly V/V to create a rich (low O2) environment.
While over-riding some sensors might be simple enough I don't think it prudent to delete the safeguards.
I have seen one of these things go without any exhaust restrictions (cat and DPF) No need for a CHIP they go like a Cut Snake and the economy also improved considerably.
I believe NISSAN have some problems with the mapping of these vehicles as the economy is inconsistent with output.
JABBA,
In another arena I have seen it suggested the Scan-gauge may be having an effect on the ECM that somehow improves economy. What's your thoughts here? (did you fit it about the time of fuel improvement?)
It was also suggested that this wouldn't be the case as the gauge only READS information, however in the field of electronics strange things have been known to happen.
Rd's
Burgo
JPMC
Member
When you guys remove the DPF if you put all the sensors back into the new pipe it doesn't effect the ECU at all as it thinks everything is as it should be.
Found this interesting article on the DPF.
Overlander 4WD :: View topic - A Explanation for Bad Fuel Economy on Navara and Pathfinder.
This could well explain variations in the D40 economy and perormance. If the DPF requires clearing, the fuel mixture is enriched to burn off the soot, hence more fuel is burnt.
This could also explain differences associated with varing fuel suppliers. I alo note the Penrite recommend an oil called enviro+ for these sort of engines. The blurb indicates:
"Enviro Plus is a range of highly advanced engine oils containing everyday synthetic base oils and the latest advances in low to mid SAPS engine oil technology. Ideal for light duty, low emissions petrol, hybrid and diesel engines including those equipped with a DPFs. "
Now the logical thing would be to bypass this pain in the a.... but the ECU and warranty issues raise there heads.
So an easier solution may be to use the right type of oil, find good clean fuel, and maybe fuel treatments? I do like the acetone/2 stroke oil additive and have used this on previous vehicles with great success, I'll have to try in in the D40.
Overlander 4WD :: View topic - A Explanation for Bad Fuel Economy on Navara and Pathfinder.
This could well explain variations in the D40 economy and perormance. If the DPF requires clearing, the fuel mixture is enriched to burn off the soot, hence more fuel is burnt.
This could also explain differences associated with varing fuel suppliers. I alo note the Penrite recommend an oil called enviro+ for these sort of engines. The blurb indicates:
"Enviro Plus is a range of highly advanced engine oils containing everyday synthetic base oils and the latest advances in low to mid SAPS engine oil technology. Ideal for light duty, low emissions petrol, hybrid and diesel engines including those equipped with a DPFs. "
Now the logical thing would be to bypass this pain in the a.... but the ECU and warranty issues raise there heads.
So an easier solution may be to use the right type of oil, find good clean fuel, and maybe fuel treatments? I do like the acetone/2 stroke oil additive and have used this on previous vehicles with great success, I'll have to try in in the D40.
Thats mine understanding too. As soon as the warranty expires off comes the DPF - replaced by this (I hope).
Attachments
Bosshog,
Fwd. of the pipe you depicted is the FLEX joint, this has a considerable restriction in it. You might consider modification up to the Cat housing, 3'' will fit within PCD on flange. Just a thought!!
Thanks for the web reference but have been through the points mentioned back in 2007.
Rd's
Thanks - thats a given as I'd replace everything forward of the rear end of the DPF replacement pipe right thru to the back of the turbo housing as I already have a 3" system post DPF.
