[ninjanayak]

Originally Posted by fhdowntheline

its observed that most diesel engines 1500cc and below are using LNT (notably Hyundai), whereas the larger engines are using SCR. Is it the case that LNT may be sufficient for smaller capacity engines?

If this is not true, then what are the chances that over a period of time, the LNT based engines may actually degrade in terms of their ability to comply with NOX emissions?

There is no limitation w.r.to engine size when choosing to go with LNT or SCR. Even small goods carrier vehicles in BS6 like Tata and Mahindra use SCR and they are less than 1L capacity.
The main thing that OEMs consider is cost, second would be the amount of NOx that engines produce. If LNT is capable of meeting emission limits then companies choose LNT. If the Engine-out NOx emissions are high and LNT may not be able to sufficiently meet those emissions targets then companies choose SCR systems.

Starting from 2023, regulatory authorities will randomly take vehicles from end users after they have been used and check if they are still within specifications. So companies design systems taking aging into account.

Originally Posted by daspranab

if I keep a diesel car (1) at home, with occasional travel to long distances; or (2) commute frequent short distances and take it for regeneration whenever there's a warning, will it be sufficient?

yes that should be ok

One more question: will the differential maintenance of a diesel car offset the savings on differential fuel price, given my usage pattern, in medium (~10 - 15k km/year) term?

I will choose not to answer this since this will change on a case to case basis.

Please let me know if you have any specific recommendation, including model, make, trim, etc. knowing we would generally travel as couple occasionally accompanied by son.

Any compact SUV by M&M or TATA, HMIL/KIA should be ok

Originally Posted by gadadhar

I own a 2021 Fortuner Diesel and was told not to switch off the engine while the DPF generation warning is on. What can be the consequences if the engine gets switched off by oversight ? Are there any further steps to be followed to minimize if there is an impact

I think they have told you this out of an abundance of caution. There should be no major impact if you occasionally turn off the engine with Regen ON. To minimize impact I would suggest you to restart the engine as quickly as possible and finish Regen.

Originally Posted by Wildy

My question is, if we have to drive in 4x4 low in 2nd/3rd gear or even on 1st on a steep inclined road where there is lots of rocks and pebbles, for 50 to 60 kms continuously with speeds varying from as low as 2km/hour (just crawling) to 20kmph, will DPF get clogged or would it regenerate normally?

This is a difficult one to answer as I have not come across such specific use case. I would suggest you to contact fellow owners or Toyota/dealer directly and get clarity.

Since it is a popular 4*4 that Toyota sells all over world, they should have thought of such use cases and accounted them into their calibration but safer to get it clarified.

[ninjanayak]

Originally Posted by --gKrish--

Coming to my question, I often see the comparison between the emissions from BS6 and BS4 engines but usually info about how we arrive at these numbers is missing. Is the comparison done for the total emission of BS6 and BS4 engine? (inclusive of the emission from BS6 when regen happens?).

Excellent question. Hopefully my answer is too long and complicated.
The percentages I mentioned there refer to the Emission targets set by the MoRTH, GoI. So if you compare the emission legislation between BS4 and BS6, the figures more or less match. Now to the question of how they are measured.
Emissions in India for BS6 are measured in a cycle called MIDC (Modified Indian Driving Cycle) for all vehicles with 4 wheels and weight less than 2.5 tons I believe (Diesel, Petrol or CNG). This cycle has 0kmph to 90kmph driving zones and lasts for approximately 20 minutes. The cycle is supposed to represent the typical driving behavior in India.
You are right that emissions are high when Regen occurs, so OEMs calculate how often and how long Regen occurs in MIDC and then a factor called Ki is applied. So the end emissions i.e. with regen and regular working cycles combined should be within the emission limits. There are clear rules that deal with regeneration systems. So in short, emission test results include Regen as well.

I often see articles mentioning that EGR reduces upto XX% of NOx emission, but we all are aware that the emission reduction is different at different RPM ranges as the percentage of EGR varies across the RPM range.
So I believe, it should be specified along with the emission reduction, at what operating RPM and load%, these measurements were taken for both engines. Also, is the emission during regen and normal working cycle varying by a large extent?

The cycle(MIDC) is designed to test most of these operating conditions; high- EGR, low- EGR and no- EGR zones, low load, high load and idle conditions, cold engine to warm engine etc. Starting 2023 with BS6 stage 2, on-road emissions along with the cycle are regulated. So companies have no choice but to reduce emissions in almost all operating conditions. The end result is a much cleaner tail-pipe. So mentioning specific operating conditions is redundant.
Coming to second part of the question, EGR is generally turned off during regen due to technical reasons involving EGR fouling, so NOx tail pipe emissions are higher by a factor of 2 or 3 during regen compared to normal working cycle. This again changes from vehicle to vehicle.

[OneLivingLife]

Originally Posted by ninjanayak

I am a Diesel Calibration Engineer by profession specializing in DPF calibration for Indian vehicles .

This thread is exactly what I was looking for. The plethora of information that you have thrown has cleared a lot of my doubts. Thanks a lot! I read each of the posts in this thread.
But, I still have a few questions (a curious mind always has its share of problems )

Originally Posted by ninjanayak

I believe there are heating elements in the DEF tank to prevent things like this. correct me if I am wrong.

I own a 2020 Thar and the manual mentions the following:



So, that clearly means at such temperatures, the car will be driven without using DEF fluid. That is partially okay as the Odo would display a 800 km warning after which Engine start will not be allowed. Again, that figure is very uncertain and drops rapidly while driving on mountain roads.
It is also mentioned that the "DEF system purges" to prevent damage from freezing. If the DEF fluid is drained / purged out, the return home journey would surely need a refill of DEF.

What are the solutions regarding this DEF? Is there any antifreeze solution that can be used?

Originally Posted by a_chelat

Also, how do we deal with DEF freezing at low temperatures? What is the recommended procedure in such cases?

I am pondering about this same thing! Does your manual not mention anything about DEF at sub zero temps?

Originally Posted by ron82x3

I own a 2020 EcoSport 1.5 TDCi with DPF and wish to remove the DPF altogether.

I read about DPF delete being done on a few cars outside India but that needs an ECU remap and is illegal too!
Also, during yearly pollution checks, you need it reverted back to the original state for a PUC.

Originally Posted by shancz

My concern still is that the diesels have spoiled a lot of drivers to carry low rpms to maximize FE, now that's going to be counter productive in this situation.

I was so thrilled to have 16-19 kmpl AFEs tank to tank when I got the BS6 diesel Thar in Nov 2020.
And, then came the Zanskar trip in Sept 2021. The car faced an OBD lock due to DEF dosing malfunction and DPF clogged at the same time. Its a long story where only the DEF errors popped up on screen during various parts of the day and the Regen error stayed for around 10 minutes. The next 5 days were spent towing the Thar for 450 kms from Padum to Leh where I spent 3 days with the lead technician at Leh getting to know about all the BS6 issues.

These days, I am happy to get a lower AFE of 12-13 on the same usual city/highway roads. It seems it is better to drive aggressively once the car warms up to have a passive regeneration every now and then. At least, the DPF and OBD locks wont be able to instill fear.

Originally Posted by ninjanayak

It's just a gas, Carbon dioxide

Wouldn't there be ash as a by product too?

I saw this guy cleaning his DPF at home! How effective is that?

https://www.youtube.com/watch?v=GnkBOtrcukI

Would something like that being done enhance a DPF's life, as I came to know DPF sets are almost 80-90k as of date?

Now, I have a few questions / doubts. Please correct me if I am wrong.

1. This DPF in the exhaust system does create some backpressure, since the free flow of exhaust is partially blocked.
Does it not affect the total life of a well maintained engine when compared to a similar Engine running without DPF?

2. In some of the BS6 trucks (probably Ashok Leyland), I saw they have a great option that shows how much % of DPF is clogged and accordingly the driver can choose to passive regenerate during a highway trip or plan it beforehand. They can also start a Park regen as per the percentage of DPF clogged. Now, my Thar 2020 or any other BS6 diesel cars do not provide this option.
Is there any affordable OBD scanner in the market that can read the Soot mass at a certain time? This would help plan a drive better and if DEF levels are shown, it would be more useful.

3. What is the average lifetime of a DPF filter considering Regens are done at proper time?

Bookmarked this thread and looking forward to know more.

[audioholic]

Originally Posted by OneLivingLife

It is also mentioned that the "DEF system purges" to prevent damage from freezing. If the DEF fluid is drained / purged out, the return home journey would surely need a refill of DEF.

I am not sure about this but I guess by purging it would circulate the DEF around the system around the exhaust injector without injecting it into the exhaust so that the heat from the parts around the exhaust will also raise the temperature of the DEF. DEF is a substance that is unacceptable to be dispensed out into the nature apart from being used in the exhaust. Hence there is no way the vehicle will actually throw out the DEF.

AFAIK, most vehicles have heaters in the DEF tank as an alternative mechanism to prevent it from freezing. I remember seeing this in my Crysta as well.

Originally Posted by OneLivingLife

I read about DPF delete being done on a few cars outside India but that needs an ECU remap and is illegal too!
Also, during yearly pollution checks, you need it reverted back to the original state for a PUC.

The issue here is, deleting the DPF using just software will be a recipe for disaster since in the absence of DPF being managed by the ECU, it will just clog up and reach a point where it is completely clogged. The only possibility is to remove the entire DPF assembly and then do a delete in the ECU to prevent any errors triggered by the absence of DPF and then a yearly activity like this is simply not worth it and would be impractical.

[a_chelat]

Originally Posted by OneLivingLife

I am pondering about this same thing! Does your manual not mention anything about DEF at sub zero temps?

Hi, I don't own a BS6 Diesel yet, but have booked the XUV7OO. Delivery in June/July (hopefully!!). I guess the manual would be quite similar to your Thar's

[ninjanayak]

Originally Posted by OneLivingLife

I own a 2020 Thar and the manual mentions the following:

Attachment 2251915

What are the solutions regarding this DEF? Is there any antifreeze solution that can be used?

Again, DEF is related to the SCR system which is completely different from the DPF, so I will not comment on it since I dont know a lot about it.

I read about DPF delete being done on a few cars outside India but that needs an ECU remap and is illegal too!
Also, during yearly pollution checks, you need it reverted back to the original state for a PUC.

DPF deletion will require you to remap the ECU and remove the physical filter and catalyst assembly from your vehicle exhaust, otherwise the filter will keep collecting soot without a way to clean it. So a ECU remap alone will not suffice. Also as you mentioned, doing this is illegal and the vehicle will not pass the emission test.

Wouldn't there be ash as a by product too?

No, soot is pure Carbon, no ash is formed when burnt at 600+ degrees.

I saw this guy cleaning his DPF at home! How effective is that?
https://www.Youtube.com/watch?v=GnkBOtrcukI

Doing this is not possible in most cars as the DOC+DPF assembly is not physically separable and I wont comment on the mystery liquid being used. Soot is just Carbon being collected, so blowing air at high velocity is sufficient to clean the DPF. So, no cleaning liquid necessary if you're able to separate the assembly.

Would something like that being done enhance a DPF's life, as I came to know DPF sets are almost 80-90k as of date?

Not required at all.

1. This DPF in the exhaust system does create some backpressure, since the free flow of exhaust is partially blocked.
Does it not affect the total life of a well maintained engine when compared to a similar Engine running without DPF?

No, the whole system is designed such that the DPF is regenerated before the increasing backpressure causes harm to the engine. Even if the Regen failed and the back pressure is very high, most vehicles go into Limp-home or reduced power mode to protect the engine.

2. In some of the BS6 trucks (probably Ashok Leyland), I saw they have a great option that shows how much % of DPF is clogged and accordingly the driver can choose to passive regenerate during a highway trip or plan it beforehand. They can also start a Park regen as per the percentage of DPF clogged. Now, my Thar 2020 or any other BS6 diesel cars do not provide this option.
Is there any affordable OBD scanner in the market that can read the Soot mass at a certain time? This would help plan a drive better and if DEF levels are shown, it would be more useful.

I'm not sure this is possible because the OEM has to enable the functionality in the ECU software. More data is required.

3. What is the average lifetime of a DPF filter considering Regens are done at proper time?

The Exhaust After Treatment system is designed keeping in mind the Full Useful Life(FUL) of the vehicle. So it would depend on your particular make and model. Generally it is in the range of 1,00,000 to 2,00,000 kms.

Originally Posted by audioholic

The issue here is, deleting the DPF using just software will be a recipe for disaster since in the absence of DPF being managed by the ECU, it will just clog up and reach a point where it is completely clogged. The only possibility is to remove the entire DPF assembly and then do a delete in the ECU to prevent any errors triggered by the absence of DPF and then a yearly activity like this is simply not worth it and would be impractical.

You are correct.

[sbm]

Hello @ninjanayak. Thanks for this detailed thread on dpf issue. I am planning to replace my 6yr old Baleno with a new compact SUV and considering the Creta and the Harrier. I want to buy the diesel version (Harrier is of cousre only diesel) for the fun to drive factor but I am not sure if my driving routine can prevent dpf clogging. Let me summarize my car usage and please bear with me as I am trying to make it as detail as possible.

1)I live in Bokaro steel city which is an industrial town with the the Bokaro Steel Plant at its heart. Dense traffic is rare except in few areas which I encounter once or twice a month.
2)The roads here are pretty wide and traffic density is such that one can maintain speeds between 40- 50kmph during most of the commute to my workplace.
3) I use my car around 10 times a month to go office as we have formed a car pool and that also means that during most of this trips, there are 3-4 people in the car.
4) The office trip is 10km each way with speeds ranging 40-60kmph during the first 5kms and during the next 5kms there is a speed limit so speed has to be below 40kmph. Total trip duration is 15-20min.
5) Every month we try to take a day trip to a nearby location at a distance of 25-30km during which speeds can reach 80kmph and seldom we encounter dense traffic.
6) I also use my car for daily chores like buying grocerries etc almost everday.
7) 3-4 times an year, we visit our home town in uttar pradesh 550km from here going through 250km on NH2 and then on Bihar state highways and UP state highways.

Overall running in last 6yrs is 52000km that makes it around 8500km per year. Would you suggest a BS6 Creta diesel or Harrier in these driving conditions? Thanks in advance.

[achintatri]

Hello @ninjanayak, Thanks very much for this highly informative and useful thread. I booked Kia Carens Diesel AT few days back due to a lot of horror stories related to petrol DCT gearbox. I wanted a petrol Engine only. Also I was happy that the diesel doesn't use adblue. I was ill informed to be honest and did not know about the dpf issues. My question is: Is there any update on the resolution of the dpf issues in the new car like Carens? Is there a km range when the dpf regeneration light will switch on ( and the regeneration can then be taken care at idling)?

Hope to receive some insight on the same from you soon and apologies if certain or all queries are repeated.

Thanks in advance!

[ninjanayak]

Originally Posted by sbm

1)I live in Bokaro steel city which is an industrial town with the the Bokaro Steel Plant at its heart. Dense traffic is rare except in few areas which I encounter once or twice a month.
2)The roads here are pretty wide and traffic density is such that one can maintain speeds between 40- 50kmph during most of the commute to my workplace.
3) I use my car around 10 times a month to go office as we have formed a car pool and that also means that during most of this trips, there are 3-4 people in the car.
4) The office trip is 10km each way with speeds ranging 40-60kmph during the first 5kms and during the next 5kms there is a speed limit so speed has to be below 40kmph. Total trip duration is 15-20min.
5) Every month we try to take a day trip to a nearby location at a distance of 25-30km during which speeds can reach 80kmph and seldom we encounter dense traffic.
6) I also use my car for daily chores like buying grocerries etc almost everday.
7) 3-4 times an year, we visit our home town in uttar pradesh 550km from here going through 250km on NH2 and then on Bihar state highways and UP state highways.

Overall running in last 6yrs is 52000km that makes it around 8500km per year. Would you suggest a BS6 Creta diesel or Harrier in these driving conditions? Thanks in advance.

The drive pattern is good, your vehicle should work alright. All the best!!

Originally Posted by achintatri

Hello @ninjanayak, Thanks very much for this highly informative and useful thread. I booked Kia Carens Diesel AT few days back due to a lot of horror stories related to petrol DCT gearbox. I wanted a petrol Engine only. Also I was happy that the diesel doesn't use adblue. I was ill informed to be honest and did not know about the dpf issues. My question is: Is there any update on the resolution of the dpf issues in the new car like Carens? Is there a km range when the dpf regeneration light will switch on ( and the regeneration can then be taken care at idling)?

Hope to receive some insight on the same from you soon and apologies if certain or all queries are repeated.

Thanks in advance!

Sadly, I dont have any such information, as they change from vehicle to vehicle and are generally confidential.
But, the engine I think is borrowed from Seltos which is a mature product and most teething problems are probably solved by now. So, I dont think you will face any issues with you new car. Have fun with your purchase!!

[arj2695]

Originally Posted by Nikhil Beke

What's your take on the ISS(idle start stop) systems on few of the small diesels, in context of DPF?

Not sure if someone had explained this before or I might have missed it.

I have read this thread with passion and eagerness to learn from a person who is well versed in DPF Systems, I myself am a Diesel Calibration Engineer, though my preliminary work has little to do with DPF or SCR systems but none the less I had a fair share of experience with these systems.

I have worked with Idle Start Stop systems (ISS) or Engine Start Stop system (ESS) [both are the same]. With most manufacturers keen to meet the CAFE targets, the ESS or ISS would become an essential tool. In regard with DPF, I can safely say that during Active Regen triggered by EMS, ESS functionality will not work (till the DPF regeneration gets completed and the drive cycle is completed). You can get to know this by Fast blinking of ISS or ESS lamp on the cluster.

[Ketan]

Thanks a lot for offering your help on this thread about the problem that is concerning most owners of BSVI diesel vehicles these days.
This is going to be very helpful the way we use and maintain this vehicle. I see M&M Thar being bashed a lot for this single reason in many threads and customers are loosing confidence in the product and technology that M&M provided. Information in this thread is surely going to help long way not only for a specific model or manufacturer but all using one with DPF, SCR or LNT.

I recently went on a volunteer work where I had to drive BSVI Thar in forest for a few days. I ran around 230kms over 3+ days on forest trails at around 20kmph (rpms were hardly around 1K or so) with 2 on board and no luggage. I continued to pay close attention to the DPF clogging warning but did not see any during this time.

Highly likely that the DPF was clean and did not clog enough to show the warning over those 230kms. 200kms ride getting to this place and coming back would have given enough chance for passive/active regen and I've not seen any alerts so far.

However, it'd be a good idea to figure a way out where we can see the percentage of the DPF that is clogged. I saw few folks from countries in west using that, just how we use aftermarket TPMS systems.

One question: Is it worth spending on an OBD interface device that can help trigger manual regen? This could be a savior if alert is not generated or missed or one is already at a limp home stage. Would this anyway interfere with the warranty or any service agreements with manufacturers?

[Nikhil Beke]

Originally Posted by arj2695

In regard with DPF, I can safely say that during Active Regen triggered by EMS, ESS functionality will not work (till the DPF regeneration gets completed and the drive cycle is completed).

No, my point of concern was with the ISS system getting active to cause multiple starts and stops during a single drive. Isn't this activity responsible for relatively more accumulation of soot (vis a vis a vehicle where the engine is kept continuously running?)

[arj2695]

Originally Posted by Nikhil Beke

No, my point of concern was with the ISS system getting active to cause multiple starts and stops during a single drive. Isn't this activity responsible for relatively more accumulation of soot (vis a vis a vehicle where the engine is kept continuously running?)

In general, for each start more fuel is needed, some are used for combustion and some end up as soot in DPF.

It would not be apt to compare both cases as other factors also influence soot accumulation. For example, if you are in a traffic signal where you have to wait for more than two minutes or in heavy traffic where the halting time is higher than in slow-moving traffic, the soot produced during the one start after the halt would be equal or less than the accumulated soot when the engine is kept idle for the entire duration.

But if it is slow-moving traffic where the gap between two starts is less than 60 sec, keeping the engine running would result in lesser soot compared to having multiple starts.

[arj2695]

Originally Posted by Ketan

One question: Is it worth spending on an OBD interface device that can help trigger manual regen? This could be a savior if alert is not generated or missed or one is already at a limp home stage. Would this anyway interfere with the warranty or any service agreements with manufacturers?

Though performing manual regeneration is a simple task, the ECU needs many other conditions to be true to start this operation. One such condition is the quantity of soot deposited in the DPF. If the Soot is beyond a threshold, then even a manual regeneration would not be possible and if forcefully performed could damage the DPF. This might cause other errors to pop up.

I would advise against doing manual Regeneration as there would be certain details and monitoring information that would not be assailable by third-party OBD interface as compared to the company provided tool.

With respect to service agreements I don't have sufficient knowledge.

[ninjanayak]

Originally Posted by Ketan

However, it'd be a good idea to figure a way out where we can see the percentage of the DPF that is clogged. I saw few folks from countries in west using that, just how we use aftermarket TPMS systems.

This feature is in the mind of a lot of OEMs based on their experience until now. As BS6 stage 2 emissions will be enforced in 2023, all cars will get new ECU software and in some cases hardware as well to meet these new emission norms and this feature is expected to be included in most if not all models releasing after 2023. So wait and watch.

One question: Is it worth spending on an OBD interface device that can help trigger manual regen? This could be a savior if alert is not generated or missed or one is already at a limp home stage. Would this anyway interfere with the warranty or any service agreements with manufacturers?

Most commercial vehicles and some cars are equipped with a button or a switch that triggers manual regen when it is pressed.
Most cars dont need this as they can comfortably regenerate using auto regen and observe good amount of passive regen as well. If there is a problem with your particular vehicle w.r.to DPF regeneration, an OBD tool that can trigger this can be a decent investment, but most vehicles will never need it. No issue with warranty if the feature is already available on the ECU and they are designed such that it gets aborted if there is a issue.

Originally Posted by Nikhil Beke

No, my point of concern was with the ISS system getting active to cause multiple starts and stops during a single drive. Isn't this activity responsible for relatively more accumulation of soot (vis a vis a vehicle where the engine is kept continuously running?)

There is a trade-off between soot accumulation due to frequent starts and fuel economy, so it depends on the OEM to make that trade-off. If the soot accumulation is negligible and the fuel savings are high then ISS is the better option and vice versa. They would run soot-loading tests with and without ISS and compare the results to see the impact of it.

Originally Posted by arj2695

In general, for each start more fuel is needed, some are used for combustion and some end up as soot in DPF.

It would not be apt to compare both cases as other factors also influence soot accumulation. For example, if you are in a traffic signal where you have to wait for more than two minutes or in heavy traffic where the halting time is higher than in slow-moving traffic, the soot produced during the one start after the halt would be equal or less than the accumulated soot when the engine is kept idle for the entire duration.

But if it is slow-moving traffic where the gap between two starts is less than 60 sec, keeping the engine running would result in lesser soot compared to having multiple starts.

Good point, as I mentioned in the above reply, they would identify a suitable trade off between activating and not activating it.

Originally Posted by arj2695

I have worked with Idle Start Stop systems (ISS) or Engine Start Stop system (ESS) [both are the same]. With most manufacturers keen to meet the CAFE targets, the ESS or ISS would become an essential tool. In regard with DPF, I can safely say that during Active Regen triggered by EMS, ESS functionality will not work (till the DPF regeneration gets completed and the drive cycle is completed). You can get to know this by Fast blinking of ISS or ESS lamp on the cluster.

I have yet to work on ISS and the project I currently work on plans to introduce it soon. I will update the thread if possible when I get more details. With respect to Regen with ISS, I would assume that there is a choice in the software between keeping it ON or OFF during regen. So tests have to be run where they would measure its impact.

Originally Posted by arj2695

Though performing manual regeneration is a simple task, the ECU needs many other conditions to be true to start this operation. One such condition is the quantity of soot deposited in the DPF. If the Soot is beyond a threshold, then even a manual regeneration would not be possible and if forcefully performed could damage the DPF. This might cause other errors to pop up.

I would advise against doing manual Regeneration as there would be certain details and monitoring information that would not be assailable by third-party OBD interface as compared to the company provided tool.

With respect to service agreements I don't have sufficient knowledge.

Some things to clarify, there are at least three types of active regen process currently being used.
Active regen, manual regen and service regen. Depending on the current amount of soot the ECU allows or blocks one or all of these.

For example, Let us assume that a DPF can hold upto 30g of soot, but it needs to be regenerated at 20g for safe functioning of the engine or other systems in the vehicle. So 20g becomes the threshold for auto regen, above which the vehicle goes into limp-home mode to protect the engine. This information is conveyed to the driver with the help of the lamp or via a message on the cluster.

Now let’s assume that the vehicle is equipped with a manual regen switch/button. Most vehicles are calibrated such that they will allow manual regen only to a certain limit, in this case lets say it is 25g. So, manual regen is allowed from 20g to 25g of soot, above which even the manual regen wont function.

This is the extreme case, where the driver must take the vehicle to the service centre where only the service device can perform the regen for safety. So, the service regen window is between 25g to 30g in this case.

If soot collected for some reason is beyond 30g, then the DPF needs to removed and replaced. There is a separate routine in the tester software to tell that ECU that a new DPF has been installed. This will erase all the values stored for the old DPF and the ECU begins calculating soot for the new DPF.

Manual and service regen are identical in functionality, the only difference being that former is done by the driver, hence the name “manual” and the other done by the tester.

Apart from the soot mass levels, there are other things to check for manual/service regen to work. Brake, clutch, gear, acc pedal status, temperature of the engine and exhaust, OBD related checks to see if there are any errors present that can inhibit regeneration etc. If all these conditions are met only then manual/service regen is performed. Similar checks are also done for auto regen to begin.