[shourya_lahiri]

Hi everyone! and thanks ninjanayak for starting this very informative thread. Have gone through all the posts and I must say there has been a fair share of valuable inputs from a lot of my learned friends.
I have a very simple query, something that has just been feathered upon in the past posts and I couldn't get a concrete explanation.
I am considering going for an offroader SUV in near future and from what I see, I am stuck with BSVI diesel motors only, as the 4X4 system is exclusive to the diesel variants only, Thar being an exception.
Now my usage is such than my car stays idle for 6 months straight (due to my occupation). occasionally my parents take out my diesel figo within the city to keep the battery alive and the car running, but that will be a futile exercise for a BSVI diesel motor and also counter productive as it will just keep on accumulating soot.
On the other hand when I am back home , my usage of the BSVI diesel SUV will be purely highway and touring purpose.
What kind of troubles am I to expect with this sort of usage routine? More accurately, how does a BSVI diesel react to sitting idle for extended time?
Please enlighten.

[skumare]

a) Does passive regen happen everytime the exhaust gas temperature reaches the required level and stop when it goes down, say burning down 25% of the soot and leaving the rest for next passive cycle?
b) How much time does it take to burn down the soot in a passive cycle in a 2.0L vehicle which has accumulated soot level at 100%?

[richie4u]

Hi experts!

A long explanation and prequel to my one line query so please bear with me.

I own a Aug 2021 Innova Diesel BS6. Its a sedately driven once or twice a week vehicle in city limits, covering about 8k kms till date.

This week we used this vehicle for a long trip which is Goa-Mysore-Ooty-Wayanad-Goa. Driven at good speeds on highways till Ooty. Being a hill station with temperature plunging to 12°c or so I faced a percular issue. Once we drove to Wayanad from Ooty and refueled at a Reliance pump I got a check engine light with drive to service station error. No dpf sensor cleaning message, nothing!

At wayanad showed the vehicle to the Toyota centre who diagnosed it as DPF error and suberror of Exhaust temperature sensor showing lower figures compared to normal (howering at 595 instead of close to 700 being optimal) The technical guy cleared the error and said it could be due to change in temperature from ooty to wayanad and if it occurs again would need to be replaced.

Now im scared of getting stuck with this error on my drove back home in the middle of nowhere so kindly guide me if this is a one off issue and what would be the best way to avoid this ?

[CretaKumar]

for starters. I20 has a DPF with LNT. DPF is put just next to Diesel oxidation catalyst which get diesel either as part of post injection or a doser valve that feeds diesel to it. Hyundai has post injection in 1.5 engines which is cause of Oil dilution at times.
Now answers to questions

1. Active regen is a phenomenon where diesel is injected in DOC to increase the temperature of DPF. When temperature of DPF increases to 500+C, soot is burnt to ash and is released to atmosphere. It happens automatically when soot load increases a certain value. There are three modes of regen Active passive and Forced. Our manual talks about forced regen

2. No, passive regen happens on long distance drives. The load on the engine itself is so high that it continues to clean DPF on its own without any extra fuel to DOC. If you are driving on highways, its most likely your RPM is at >1750RPM. This itself aids for passive regen along with some chemical reactions.

3. With my personal experience you will get better fuel efficiency if you drive in Turbo range (i.e 1700- 2000RPM)
However its not necessary to drive at that RPM. Hyundai has releases an ECM update in month of June that take cares of DPF issue. With this update active regen occurs more frequently and hence its not compulsion to dive at 2000RPM . If you are driving your car everyday, that will be more than enough. I am a city driver and never got DPF light ever (15000Kms)

Final Answer, It wont matter if you drive in city or highway if you are driving 40Kms daily. However it is advisable to take cars on highways but not mandatory.
Since you are driving 18Kms in 50 min. I would suggest you to notice one important thing. Notice how your FE will temporarily drop for first 15 KMs every second day. If you see that consider active regen is happening in background where extra diesel is sent to your DOC.

[Phukan23]

https://youtu.be/SR1x7eDqmJ8

Is this process genuine and reliable. Please look into the video and share your detailed inputs.

[haribalram]

With BS6 compliance guidelines in place, does GoI still mandate pollution certificates every 6 months (after the 1st year if ownership)? Checking, since the cars themselves have a continuous monitoring and self-healing mechanism now. Thanks.

[Rigid Rotor]

Originally Posted by haribalram

... BS6 ...pollution certificates every 6 months (after the 1st year if ownership)? .

The PUC Certificate for BS6 engine vehicles is valid for a period of 12 months from the period of test.

I just got the PUCC for my BS6 diesel vehicle, a week ago after having completed a year of ownership.

[josetom89]

I have a query regarding DPF in Honda Diesel. I currently own an Amaze Diesel CVT BS6(2020) model. It has clocked 43000 kms till date. I was called by my ASC for a mandatory DPF update at 34000 kms. Further to that update my mileage dropped from 18 km/l to 16-16.5 km/l. I queried with my ASC but they were totally clueless and blamed my driving. I decided to go ahead with this and wait till next service. I did the 40K service around a month back. 40K service is a major one which includes transmission oil change as well. I was expecting the mileage to be better after this however the mileage dropped further. Now it hovers around 15.5 kmpl. I consulted another ASC in my area and they said they can only reset DPF after an oil change. Till date i have not received any check engine light or other warnings. This new ASC recommended to observe any warnings or issues with power delivery. Power delivery seems fine till now and i have clocked 3000 kms post service but mileage is still the same.
Dear BHpians, Any idea on what could have gone wrong here ? All these happened after the DPF update. Prior to that everything was fine. Mine is a small town with smooth traffic flow in general.

[ninjanayak]

Originally Posted by shourya_lahiri

What kind of troubles am I to expect with this sort of usage routine? More accurately, how does a BSVI diesel react to sitting idle for extended time?
Please enlighten.

No issues to DPF by keeping the vehicle idle for extended periods of time.

Originally Posted by skumare

a) Does passive regen happen everytime the exhaust gas temperature reaches the required level and stop when it goes down, say burning down 25% of the soot and leaving the rest for next passive cycle?

There are some more things that affect passive regen, but yes the exhaust temperature is the most important parameter for good passive regen. Therefore, passive regen happens everytime the exhaust gas temperature reaches the required level and stop when it goes down

b) How much time does it take to burn down the soot in a passive cycle in a 2.0L vehicle which has accumulated soot level at 100%?

Passive regen cannot completely burn the accumulated soot, only active regen can do that, but it significantly reduces the amount of soot getting collected. From the projects I have worked on, roughly 200-250km driving is required for good passive regen performance.

Originally Posted by richie4u

At wayanad showed the vehicle to the Toyota centre who diagnosed it as DPF error and suberror of Exhaust temperature sensor showing lower figures compared to normal (howering at 595 instead of close to 700 being optimal) The technical guy cleared the error and said it could be due to change in temperature from ooty to wayanad and if it occurs again would need to be replaced. Now im scared of getting stuck with this error on my drove back home in the middle of nowhere so kindly guide me if this is a one off issue and what would be the best way to avoid this ?

Its difficult to find a problem with such limited info, but the temperature sensors cannot malfunction because of ambient temperature. They are just sensing elements. Your issue may need to be looked at more deeply.

Originally Posted by CretaKumar

1. Active regen is a phenomenon where diesel is injected in DOC to increase the temperature of DPF. When temperature of DPF increases to 500+C, soot is burnt to ash and is released to atmosphere. It happens automatically when soot load increases a certain value. There are three modes of regen Active passive and Forced. Our manual talks about forced regen

Correct.

2. No, passive regen happens on long distance drives. The load on the engine itself is so high that it continues to clean DPF on its own without any extra fuel to DOC. If you are driving on highways, its most likely your RPM is at >1750RPM. This itself aids for passive regen along with some chemical reactions.

Correct

Originally Posted by Phukan23

https://Youtu.be/SR1x7eDqmJ8 Is this process genuine and reliable. Please look into the video and share your detailed inputs.

The video is very exaggerated, no need for such actions unless you drive at very low speeds (<20kmph) on a regular basis. Regular rural driving mixed with some highway drive should be sufficient.

Originally Posted by haribalram

With BS6 compliance guidelines in place, does GoI still mandate pollution certificates every 6 months (after the 1st year if ownership)? Checking, since the cars themselves have a continuous monitoring and self-healing mechanism now. Thanks.

I am not very knowledgeable regarding this, but I assume you need to get the pollution checks done at regular intervals. This may be to make sure that no modifications were done by the owner after the purchase.

Originally Posted by josetom89

Dear BHpians, Any idea on what could have gone wrong here ? All these happened after the DPF update. Prior to that everything was fine. Mine is a small town with smooth traffic flow in general.

Your FE will drop by 3-4kmpl only during regen events, i.e. for 20mins every 200km for example. DPF has no impact on your FE during regular driving, i.e. without DPF regen. So, it may be just the regular wear and tear of the engine and its components that caused the drop in FE of your vehicle or there were other changes to the vehicle software in addition to DPF updates that may have caused this. Contact Honda directly for more information,

[justwheels]

Firstly many thanks @ninjanayak for the insightful details on dpf.

One specific question, I and some friends are planning a winter spiti ride with many Thars few of them being diesels. We have heard few dpf issues with winter driving in mountains in sub zero temperatures. Any recommendations what we can do or avoid doing to save ourselves from dpf issues.

Thanks in advance.

Deb

[sbm]

Hi @ninjanayak. Good to see you back after a long break. I bought a XUV700 diesel manual after much deliberation and taking some risk as my use case definitely points to petrol car but I needed a powerful engine. So here is my obervation about DPF and a few questions
1)In the first 1000km, I did 400km highway and during my first service I got to know that soot mass is 19g. There was no regen warning. Mechanic did a service regen and cleared the soot but he was not able to clarify why didn't I receive a warning. I got to know from the service software that 0 to 37g is the range in which they can perform service regen. Above that, only Mahindra technical team can do it by taking the system online.
2) Next I went there at 1860km for some other job. I asked them to checked the soot level and found it to be 14g. These 1000km were inside my city only (no bumper to number traffic but I did use the car for daily short trips).
My question is,
1)why didn't I receive a warning if the soot mass was nearly half of the limit of 37g. Should I anticipate some problem with the warning system or can the warning level be much higher than 19g?
2) Why didn't the car perform active regeneration during the first 1000km event though it had a good amount of highway run during that period? Is there some problem with the active regen system and if it is,will there be a warning for that?

[arj2695]

Originally Posted by sbm

1)In the first 1000km, I did 400km highway and during my first service I got to know that soot mass is 19g. There was no regen warning. Mechanic did a service regen and cleared the soot but he was not able to clarify why didn't I receive a warning. I got to know from the service software that 0 to 37g is the range in which they can perform service regen. Above that, only Mahindra technical team can do it by taking the system online.

For most Mahindra vehicles including XUV 7OO, the max soot for triggering Active regeneration is 24 gms in Sea Level, it would change with altitude. A green "REGEN" lamp would pop up only if the soot is beyond this. That is, even after reaching 24 gms, the engine is not able to perform regeneration due to boundary conditions. A service regeneration can be performed till 37 gms, because beyond which doing regeneration can cause the DPF brick related issues.

2) Next I went there at 1860km for some other job. I asked them to checked the soot level and found it to be 14g. These 1000km were inside my city only (no bumper to number traffic but I did use the car for daily short trips).
My question is,
1)why didn't I receive a warning if the soot mass was nearly half of the limit of 37g. Should I anticipate some problem with the warning system or can the warning level be much higher than 19g?

2) Why didn't the car perform active regeneration during the first 1000km event though it had a good amount of highway run during that period? Is there some problem with the active regen system and if it is,will there be a warning for that?

Regen lamp will only pop up if the soot mass is beyond the threshold. I understood from some Mahindra technicians that when active regen is being done, the engine functioning is ensured to be at par with how it would perform when in normal driving. So it would be difficult to differentiate when the vehicle is in Regen or Normal driving. In the 1000 kms, the vehicle would have undergone multiple active regen, and hence the soot loading cannot be directly correlated with out knowing certain other values such as kms driven post last successful active regeneration.

Hope this helps.

[sbm]

Originally Posted by arj2695

For most Mahindra vehicles including XUV 7OO, the max soot for triggering Active regeneration is 24 gms in Sea Level, it would change with altitude... .... DPF brick related issues.
..
Regen lamp will only pop up if the soot mass is.... values such as kms driven post last successful active regeneration.

Hope this helps.

Thanks for this info; it eases my mind a lot. By the way, what is a "brick related issue"? Does that mean that DPF will become damaged and useless? The guys at the service centre said above 37 g, only Mahindra's technical team can do regeneration by taking the system online.

Regarding active regeneration, what I understood from this thread is that there is some sort of indication when active regeneration is going on while driving. That's why I was confused why the car was not performing active regeneration, but now I know that there won't be any signal for that..

[arj2695]

Originally Posted by sbm

Thanks for this info; it eases my mind a lot. By the way, what is a "brick related issue"? Does that mean that DPF will become damaged and useless? The guys at the service centre said above 37 g, only Mahindra's technical team can do regeneration by taking the system online.

Brick Related Issue - during service regeneration, if the brick temperature exceeds beyond a threshold, it would lead to damage. This can happen if regen is tried when soot is above 37gms. If it is done by Mahindra's technical team, they will have control over temperature.

Hope this helps.

[ninjanayak]

Originally Posted by justwheels

We have heard few dpf issues with winter driving in mountains in sub zero temperatures. Any recommendations what we can do or avoid doing to save ourselves from dpf issues.
Deb

Cold temperatures generally dont cause any problems to DPF, its the altitude that may lead to issues. But I'm pretty sure Mahindra have done extensive testing in these regions to a very popular and high selling model. So, I don't think you will face many issues.

Originally Posted by sbm

1)In the first 1000km, I did 400km highway and during my first service I got to know that soot mass is 19g. There was no regen warning. Mechanic did a service regen and cleared the soot but he was not able to clarify why didn't I receive a warning. I got to know from the service software that 0 to 37g is the range in which they can perform service regen. Above that, only Mahindra technical team can do it by taking the system online.

The soot capacity of a DPF changes from model to model, type and size of the DPF used. So, only the OEM will know the capacity of their models.

2) Next I went there at 1860km for some other job. I asked them to checked the soot level and found it to be 14g. These 1000km were inside my city only (no bumper to number traffic but I did use the car for daily short trips).
My question is,
1)why didn't I receive a warning if the soot mass was nearly half of the limit of 37g. Should I anticipate some problem with the warning system or can the warning level be much higher than 19g?

2) Why didn't the car perform active regeneration during the first 1000km event though it had a good amount of highway run during that period? Is there some problem with the active regen system and if it is,will there be a warning for that?

The point at which the DPF regen is required is governed by the ECU, there are multiple conditions checked before a regen is requested by the ECU. The amount of soot already present, the current driving behaviour, in some cases the predicted future driving behaviour etc.
In your case, I'm assuming there was very little soot present during the highway drive, therefore the ECU decided that there was no need to waste fuel trying to do a regen and that the regen could be performed at a more efficient and feasible opportunity.

Originally Posted by sbm

Thanks for this info; it eases my mind a lot. By the way, what is a "brick related issue"?
Regarding active regeneration, what I understood from this thread is that there is some sort of indication when active regeneration is going on while driving.

A cross section of the DPF looks like a brick that is used for construction, hence the name brick. As answered by arj2695, high temperatures above 900degC can cause damage to them and repeated exposure to such temperatures can cause irreversible damage to it. After this the DPF needs to be replaced. But there are many safeguards in the ECU software that prevent this from happening.
Regarding the indication of regen, it depends on the OEM to implement it on their models. Some do it while some don't.