D P F burn off routine

[watsea Member Find all posts View Profile Close watsea]

My 2019 Prado did not come with a manual button but there are instructions about how to run if a DPF burn needs to occur if it does not go automatically. So far no hassles for my vehicle, though much of the driving is highway driving over 1-2 hours or longer trips. I have TorquePro app for engine and transmission monitoring but often too busy driving to see what the typical distance interval is for normal driving. Probably about intervals of 300km under normal driving but closer together under hard conditions.

Although I do see when a burn occurs by seeing the DPF% change, always starts a burn at 100% and burns down with 5th injector operating. I notice the fuel consumption increases by a couple of Litres/100km during a burn. The last two Exhaust Gas Temperature Sensors have increased temperatures during a burn, over 500degC or more

The 5th injector seems to cut off around 8 to 6 DPF% and regularly the DPF% will decrease to 0 or 2% presumably due to some residual heat if the vehicle continues. If the vehicle is shut-down during a burn, a burn will restart, whether in an urban trip or a longer trip, so that DPF% goes to low value. I have read somewhere that often some DPF%s often only go to 8% without problems.

[RPP Senior Member Find all posts View Profile Close RPP]

If you don't have the manual button ask your Dealer to install one and enable Custom Mode 2.
But ring around first and find a Dealer that has done it before, otherwise there mite be much teeth gnashing.

The DPF manual button came with Prado's from late 2018 onwards. Mine's a Feb 2018 GXL and had the Dealer retrofit the button (for free), and enable Custom Mode 2.

I've logged all DPF burns since new - see latest post on DPF statistics:
https://www.pradopoint.com.au/forum/...s-0-160-000kms

Since the ECU firmware update, circa 2019, the DPF burn cycle looks to have changed from fixed to adaptive. DPF burns occur over a wide range of intervals.
Also, 100% means something different depending on Highway (at speed) or City (slow) driving cycle.

It get as hot as Hades in the last phase of the Burn. Typically 650-700C but I've logged burns peaking over 700C, with one at 733C!
Aluminium melts @ 660C.

[GeeWhizz Senior Member Find all posts View Profile Close GeeWhizz]

My 2016 has had the latest dpf fitted and works fine. Custom modes 1[a light] works fine. As to custom mode2 [a switch], it is fitted but despite 4 attempts the dealer cant get it to work. They claim it only works at 180%. Who knows. My scan gauge shows burns at 100% about every 270-280 km around town but much more frequently on the highway.

Having had my original DPF up to 180% I can say that, at the very least, you're about to enter limp-home-mode. And limp-home-mode makes the Prado horrible to drive (been there, done that)! From my experience, if the DPF gets to 180% nothing is going to bring it down again: not even a manual burn switch - the 5th injector will be crusted over with soot and unable to do its job.

[GeeWhizz Senior Member Find all posts View Profile Close GeeWhizz]

Although I do see when a burn occurs by seeing the DPF% change, always starts a burn at 100% and burns down with 5th injector operating. I notice the fuel consumption increases by a couple of Litres/100km during a burn. The last two Exhaust Gas Temperature Sensors have increased temperatures during a burn, over 500degC or more

The 5th injector seems to cut off around 8 to 6 DPF% and regularly the DPF% will decrease to 0 or 2% presumably due to some residual heat if the vehicle continues. If the vehicle is shut-down during a burn, a burn will restart, whether in an urban trip or a longer trip, so that DPF% goes to low value. I have read somewhere that often some DPF%s often only go to 8% without problems.

I concur with this. Attached is a real-time log of a burn in my MT2016 Prado GX. The dotted line represents 100% (on the RH vertical axis)

[grunfalo Lurker Find all posts View Profile Close grunfalo]

My 2016 has had the latest dpf fitted and works fine. Custom modes 1[a light] works fine. As to custom mode2 [a switch], it is fitted but despite 4 attempts the dealer cant get it to work. They claim it. Only works at 180%. Who knows. My scan gauge shows burns at 100% about every 270-280 km around town but much more frequently on the highway.

your dealer has no clue what custom mode 2 is or how to enable it.
Custom mode 2 enables you to activate dpf regen at the two bars or at 28% of dpf level, this is clearly written in owners manual book as well.
I had to take my car to two dealerships in order to finally have custom mode 2 enabled, as the first dealership attempted few times and could not get it done

[404pug Avid PP Poster! Find all posts View Profile Close 404pug]

Does anyone know of a Sydney or Wollongong dealer who CAN activate custom mode 2 [the button is there].?

[humungusmon Junior Member Find all posts View Profile Close humungusmon]

How does the dealer 'activate' custom mode 2? Is it something done by Techstream? Has anyone managed to activate Custom 2 without the dealer's intervention? Thanks.

[TheFloyd Lurker Find all posts View Profile Close TheFloyd]

It has been a really interesting read-through of what everyone else has been experiencing. Also, super impressed with your custom Scan UI, GeeWhizz!
Here is my experience with the scenario. I have a from-new 2017 GXL, and not had any problem with it ever. love it. however in the last 6 months, i started noticing the frequent plumes of white smoke, worse fuel consumption and it would have periods where it just felt sluggish. I mentioned this at my next service and they immediately booked it in for a replacement ECU.

The interesting thing is that when the DPF saga kicked off, i was contacted quickly and took my recalled car to have the DPF inspected and a new "CAL File" installing. I took it in and they gave it back to me and said "All good". it has been a couple of years now and i continued to have no issues. however as mentioned earlier, in the last 6 months, i started to notice the changes. the biggest thing was that i am certain my around-town and highway fuel consumption was about 2L/100KM worse than it has always been, and some days the car just "felt fat and slow" for no good reason.

skipping forward to December 2023 when the local dealership replaced the DPF. They did it in a day, and when i got it back, they told me that it had a new DPF but more interestingly "It had the original CAL file, which they have now updated". I am assuming that a "Cal File" is their abbreviation for an ECU Calibration file, as in new ECU firmware? so it sounds to me like back in 2019 (or whenever it was that it was recalled), they didnt actually re-brain my ECU, and over time my car's DPF was gradually suffering the fate of so many.

anyway, they were really good about it, and as normal, they did a fantastic job. the even better news is the immense difference to the way the car drives. While i assumed that having a blocked DPF must negatively impact the efficiency of the exhaust system and in-turn the engine performance, I am astonished how much more responsive the engine is and improved my fuel usage is. i have re-gained the 2L/100KM in around-town driving and on the highway, it isnt reluctant to change down into top gear anymore. I no longer feel like i am constantly having to 'push' the car to maintain speed on the highway.

as for the DPF operation: while i dont have the impressive GeeWhizz solution, i have an inexpensive aftermarket head unit that came with one of those cheap OBDII bluetooth modules. This does however allow me to run a custom dashboard that shows three EGT sensors, and the DPF soot level. with the latest toyota CAL-File and a new DPF, I have observed the operation to be as follows, over the past 6 weeks.

if i do horrible driving, like being stuck crawling in traffic, i find that the DPF soot will build up fast, even with very few KM's traveled. eg, on a really bad commute day, I watched my DPF level go up by about 35% in a single drive over about 20km to work. if i drive the same commute in light traffic and have a good run on the lights, it might only go up by 4-6%

I wanted to give it a good highway run, and this was what astonished me. It filled up a LOT less than in horrid slow traffic. I woudl say it only increased by about 8% over 150+KM of nice open highway driving, and it was only increasing faster than that when pulling up an extended hill at highway speed, which makes complete sense given the increase load on the engine.

with the new CAL file, as soon as it displays at 100% DPF, it initiates a burn. unlike previously, this was almost invisible to me or others. EGT sensor 1 rarely changes from the normal 200-350 degrees range. but EGT-S2 quickly heats up to about 500-600 degrees and the DPF level rapidly starts decreasing over only a matter of minutes. EGT-S3 heats up into the 500's, but then when the DPF level gets to around 30%, the burn program must adjust, and EGT-S3 heats right up to around 700 degrees and EGT-S2 cools off to around 500. Once the DPF level gets to about 8%, everything starts cooling off and by the time DPF=4% all the EGT temps are back to normal. one time it hit 100% a I literally pulled on the handbrake in my drive. I just sat there for 5 minutes and it did its thing with no fuss and burnt it off, without even lots of revving and smoke etc. the only thing i noticed, is the general "Hot Smell" when i got out the car, which is pretty understandable.

With this new CAL file, there is no white smoke at all. it will happen anywhere, and doesnt seem to equire highway speeds or minimum RPM. if it needs to trigger while you are crawling through a city, it will. also, if it is part-way through a regen and you have to stop for a few minutes at a shop, when you start the car up and continue driving, it picks up where it left off and finishes the burn process. I have actually observed that the only noticeable thing in the burn process, is that sometimes it will want to stay in a higher gear and maintain a few extra RPM, but not enough that if you were not looking out for it, you wouldnt even notice.

obviously i am pretty happy with the outcome here, and that my beloved P150 is back kicking goals again! i am a technical person, so this has triggered a slightly obsessive interest in understanding more about the software and logic in the new ECU firmware. I would love to know what parameters are in the new CAL file, and what has changed in terms of engine management from the stock CAL file that i was running until recently. I'd love to know if there is a known regen algorithm, and how closely it matches the EGT temps and overall process that i can now see happening. I'd also like to know what other engine management parameters are included with this update, beyond just the DPF regen logic. I even recorded the CAL file ID's for the before and after version, in the hope that there may be some information out there about their detailed function. what i can say, is that it may be a placebo, but i dont think my Prado was this perky even on the day i bought it. it feels like other ECU tuning improvements have been made since 2017 and perhaps this CAL file update has pushed them across my 2017 ECU? you get to know your car, and i dont think the positive changes are in my mind.

couple of last points. I still see hilux's and prados on a weekly basis that are cruising around Brisbane with a cumulonimbus of white smoke coming out the back of them. If you are one of these people, dont delay, just go into Toyota and tell them that your car pumps out a storm-cell of white smoke all the time and feels sluggish. shazam, you will hopefully then have the fantastic outcome that i have jsut had, at no cost.

one last thing : one of the properties that the OBDII tool presents to me in the carscanner app UI, is "Manually Trigger DPF Burn". I have not fiddled with that yet, and dont know if it does anything. I dont have the physical regen button, but reading the conversation above about "Mode 2", i am wondering if this could be how that is being presented?

finally, if you have some juicy details on what the parameters are in these CAL files, i would love to know more.

i hope that wall of text may be interesting to someone
Floyd.

[RPP Senior Member Find all posts View Profile Close RPP]

Once upon a time the DPF burn cycle was directly related to he differential pressure across the DPF.
The pressure variation was "mapped" to the arbitrary 0-100% scale. The DPF burn cycle begins at 100% (whatever that translated to in pressure delta).
Following the ECU firmware update, circa 2018-19, the burn cycle became more adaptive.

After a Burn is complete the DPF saturation metric now (seemingly) grows quickly to somewhere in the mid 50% region whereup it slows down and can go into reverse!.

What happens from there on is dependent on if you are driving at highway speeds (ie. hi load condition) or mooching around town.
At highway speeds the burn cycle comes on much more often than at city speeds.

Check out the double-peak graphs at https://www.pradopoint.com.au/forum/...s-0-160-000kms