D P F burn off routine

[Jackrustle Lurker Find all posts View Profile Close Jackrustle]

Hi to all.

I have a 2016 2.8 diesel Prado & want to find out how often the D P F should burn off.

With general driving around town I expect it to burn off from time to time, however on a recent long drive, 300 + km, at highway speeds,

when I slowed down the engine revs increased & it seemed to go into burn off mode. After a long drive this is not what I expected.

The vehicle has aprox 120 thou Kms & I have owned it for about 18 months, only had 100 thou kms when purchased.

The D P F was replaced about 10 months ago under warranty by my local Toyota dealer.

Any thoughts on this problem would be greatly appreciated.

Life is busy at the moment, so apologies for delayed replies to responses.

Regards, Russell ...............

[gunda Member Find all posts View Profile Close gunda]

My MY21 Prado does a burn roughly every 250-300kms, so if you got the current system when yours was replaced then that's about right.

Before buying my Prado I was under the impression that diesels would to a passive burn if driven enough at open road speeds, rather than an active burn. But I see no sign of passive burning. This is a disappointment.

[Jackrustle Lurker Find all posts View Profile Close Jackrustle]

Hi gunda.

I'm currently reading other DPF articles in the forum + other posts as I have not been on the forum for some time.

Thanks for your reply, I am keen to see responses from others.

Regards, Russell .............

[ptommo59 Senior Member Find all posts View Profile Close ptommo59]

Hi Jackrustle,

Did they enable Custom Mode and put the Manual Burn Switch in when they did the update?

As these should give you the visual indication when a burn is occurring and if you also get Custom Mode 2 enabled as well you can do a Manual Burn from as low as 28% soot load instead of only when the Auto Burn has not been successful at maintaining levels below 100% (Excluding a fault condition this would normally happen when you do regular short distance and/or start stop drives and never get the engine up to full coolant temp long enough to commence or complete a burn).

An effective Passive Regen would require the EGTs at the DPF to be above 500 C but I have monitored mine under normal driving conditions including towing and rarely see them go past the mid 400s unless you labour the engine in a higher gear under load; where it can get over 500 but it will quickly drop back down to normal range as soon as you drop a gear and increase revs so limited ability to reduce the DPF soot load as the labouring of the engine also creates extra soot output due to the extra fuel being burned in the cylinders.

[Brisbane4101 Lurker Find all posts View Profile Close Brisbane4101]

I've a 2022 GXL with 20,000km on the clock, and it is pretty religious doing a dpf burn around 300km, doesn't matter if I am city driving, towing the boat, or been driving on the hwy at 110.
It gets to four vertical bars on the dpf graph (there are about 8 bars I think, i'll check next time I am in the car) and at four bars is when the burn starts.

[Jackrustle Lurker Find all posts View Profile Close Jackrustle]

Hi ptommo59.

Thanks for your detailed & knowledgeable response. The dealer did say they did an ECU upgrade when they replaced the DPF but have not fitted a manual burn switch.

I will try to see them sometime soon to ask about your other ideas & custom mode 2.

I / we have a good relationship with the dealer through our 4wd club. The Toyota Landcruiser club of SA. so I hope they will be straight forward & truthful with their responses.

Hi Brisbane4101.

Thank for your response as well. Do you have a scan gauge plugged in to your Prado to see the "bars" you talk about or is this a standard feature of later models.

I haven't kept a check on km's between burns but 300kms seems about right, or possibly less around town.

Again. Thanks for your replys.

Regards, Russell ................

[ptommo59 Senior Member Find all posts View Profile Close ptommo59]

Hi Jackrustle,

The coloured bars are standard on the DPF screen on the Aug 2020+ models - Not certain if that screen is also included as part of the Custom Mode firmware updates for earlier models after retrofit with the latest DPF configuration.

If you haven't already seen it take a look at this Toyota DPF booklet which explains it all DIESEL PARTICULATE FILTER (DPF) INFORMATION BOOKLET (au.s3.amazonaws.com)

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

I have a 2016MY GX Prado and have been through the entire process of white smoke and the software fix, followed a few months later be the 5th injector failing and clogging the DPF. This was replaced under warranty and the Prado has performed perfectly ever since. The 2016 Prado did not come with a 'burn' button and you will not get one added by Toyota (although early failures may have been upgraded).

A diesel engine is a diesel engine is a diesel engine. When it works hard it makes black smoke (soot) - there is no getting away from it. The DPF collects most of this soot and, when the filter gets choked up (to a "100%" level), the ECM initiates a burn off. Under heavy load, this could happen every 50km. Under light load, it will have a much longer break between burns. If you monitor the soot load with a CAN/OBD monitor, you will see the soot load build up from around zero to 100% - the time and kilometres will vary.

[Jackrustle Lurker Find all posts View Profile Close Jackrustle]

Hi ptommo59.

Thanks for the info. My 2016 model does not have the PDF display screen, but as I said previously the DPF has been replaced recently & all is running very well.

I will certainly read the link to the DPF info booklet. I like to know how things work & it they can be fixed ??? when in remote locations.

Hi GeeWhizz.

It seems your Prado has had a few problems. I hope it is sorted & you are happy with the vehicle now.

A scan tool is something I will put on my shopping list. Is there a recommended brand/model for the Prados. I know they can vary in price & features greatly.

I must keep on the go as I am fitting my lift kit today.

Thanks again. Regards, Russell ..............

[Loddo Lurker Find all posts View Profile Close Loddo]

I have now completed a 5k trip towing my van and it has not carried out a DPF burn, according to the scangauge i have fitted the DPF level is sitting at 20 and if you check the dash display it shows only one bar so I assume that the DPF is hot enough to do a passive burn.

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

....Hi GeeWhizz.

.....It seems your Prado has had a few problems. I hope it is sorted & you are happy with the vehicle now.

A scan tool is something I will put on my shopping list. Is there a recommended brand/model for the Prados. I know they can vary in price & features greatly.

As I said in my post: "...the Prado has performed perfectly ever since.".

I can't recommend one specific OBD monitor. I designed and built my own to my own specification - refer to the DPF screen below. The unit displays the DPF data in real time as I drive.

[ptommo59 Senior Member Find all posts View Profile Close ptommo59]

GeeWhizz

That pretty impressive and figures align with what I have been seeing (so nowhere near hot enough for Passive Regen to occur).

The PM Accumulation Ratio Bank 1 (DPF Soot Load %) is a calculated figure and in 2% increments which is probably why it steps like that. From what I can make out the DPF Differential Pressure Sensor reading is one of the inputs for the calculation, but this fluctuates significantly with RPM as well as the soot load in the DPF so couldn't be used without some sort of averaging and/or use with another parameter like fuel used/km travelled to give you a %.

[Brisbane4101 Lurker Find all posts View Profile Close Brisbane4101]

it's a console display, and my model also has the manual dpf burn switch, but I have never actually actuated it, the auto burn kicks in before it will allow a manual burn.

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

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.

[Jackrustle Lurker Find all posts View Profile Close Jackrustle]

Hi to all who have responded.

Thanks for your input, it has given me a greater understanding of how DPF's work & mine seems to be functioning properly.

We are heading away this coming weekend for a 4 day trip to the Flinders Ranges so another good run for the vehicle & a test for the lift kit just fitted.

Regards, Russell ..................