A wee something to look at...

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STP
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Re: A wee something to look at...

Post by STP »

stu_b wrote: Mon Jul 07, 2025 8:48 am All noted

Is this sort of thing already available in the market for other vehicles with DPF's ??

I'm intrigued to know more

Cheers
Stu
Hi Stu_b, it would be easy to be cheeky like some device developers and lock it to one VIN but no, the intention was you could move it and the chosen obd adaptor to another vehicle and it should work fine. It reads the VIN and the use for that was to identify the vehicle as being one it has the correct IDs for to request the data needed as the wrong codes used will produce no results and the 1.6 for example uses different codes from the 2.0 to get the same data. The soot (and all other data) is read live from the ECU - I know for example that the 1.6 will get up to 24g of soot, at which point if the other conditions are right (more than 1/4 tank of fuel and up to temperature) then a regen will start and burn down will continue until the calculated soot is below 5g, though for example if you get down to 13g and then park up, stopping the regeneration, it will not restart the same regen until 24g is reached again.

70g of oil ash residue is also a max figure obtained from the data and the ECU would consider this 100% full and would no longer allow any regeneration to take place. You would get a warning light on the dash at that point. So the values I use are genuine and not estimated.

I first built an emulator which does a good job of pretending to be my van, and tested it against some industry standard tools, so I know the values are correct, but of course I have a 1.6 and that was the tricky one to do, as the uds codes are not in the public domain. Reverse engineering for many weeks was required to crack that nut.

Finally there is no device I can see which does the same thing in a compact display without using a mobile or android apps and even then, good luck getting the VW 1.6 to work with them (also the most common engine too) as the Simos code is very tightly guarded by Siemens. I haven't seen anything for other vehicle brands either.

The goal was to get a simple display, of live data, constantly on the dash so the user knows exactly what is going on. No fiddling with a mobile app while driving.
2015 SWB Van, 1.6 CR TDI with Cruise Control, Heated Mirrors, Highline Clocks & MFD, VW Hands Free Bluetooth, Electric Windows, Reversing Cameras, DPF Monitor, Thatcham Cat 2.

My build thread: White MK3 Facelift

My DPF Monitoring Device thread: DPF Monitor
STP
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Re: A wee something to look at...

Post by STP »

PJD wrote: Mon Jul 07, 2025 9:12 am Really clever but of kit and £30 makes it an easy decision.
Thanks mate.
2015 SWB Van, 1.6 CR TDI with Cruise Control, Heated Mirrors, Highline Clocks & MFD, VW Hands Free Bluetooth, Electric Windows, Reversing Cameras, DPF Monitor, Thatcham Cat 2.

My build thread: White MK3 Facelift

My DPF Monitoring Device thread: DPF Monitor
STP
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Re: A wee something to look at...

Post by STP »

kobat79 wrote: Mon Jul 07, 2025 5:02 pm That's really impressive. Nice work. My Caddy doesn't have a DPF but my Mk7 Golf does. Would this work on that? I'd be interested in one if it does.
Hi kobat79, thanks. I have yet to expand the codes to cover the 2.0 but I do have lots of info for those so it should be straight forward. If it's a 1.6 tdi then yes it should work. It's early days but results so far have been really good. It takes time to write the software in between my (busy) day job, but progress is so far pretty good too.
2015 SWB Van, 1.6 CR TDI with Cruise Control, Heated Mirrors, Highline Clocks & MFD, VW Hands Free Bluetooth, Electric Windows, Reversing Cameras, DPF Monitor, Thatcham Cat 2.

My build thread: White MK3 Facelift

My DPF Monitoring Device thread: DPF Monitor
Janisa
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Re: A wee something to look at...

Post by Janisa »

Thanks for sharing about this suggestions and information,I learned a lot from it.I hope I can read more related topics in the future.
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stu_b
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Re: A wee something to look at...

Post by stu_b »

I am very intrigued by all of this
Would it be transferable to other marques, not just in the VAG group ?
Ie for Mercedes, Fiat, Ford etc etc

Question, and sorry if this is a silly question, but am I right in thinking not all diesels have a dpf ?
Is it dependant on country and emissions etc ?
Also, another silly question, there are a lot of people swapping engine on here n out there
When they swap from one to the other, the vin stays the same but would they have to code in (with the likes of VCDS etc) the new particulars of the new engine so that the system (ECU) can read and diagnose the network of electronics n engine etc etc

I think this is an amazing tool to help the user easily identify your engine management of the DPF system
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Javito
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Re: A wee something to look at...

Post by Javito »

STP wrote: Hi Stu_b, it would be easy to be cheeky like some device developers and lock it to one VIN but no, the intention was you could move it and the chosen obd adaptor to another vehicle and it should work fine. It reads the VIN and the use for that was to identify the vehicle as being one it has the correct IDs for to request the data needed as the wrong codes used will produce no results and the 1.6 for example uses different codes from the 2.0 to get the same data. The soot (and all other data) is read live from the ECU - I know for example that the 1.6 will get up to 24g of soot, at which point if the other conditions are right (more than 1/4 tank of fuel and up to temperature) then a regen will start and burn down will continue until the calculated soot is below 5g, though for example if you get down to 13g and then park up, stopping the regeneration, it will not restart the same regen until 24g is reached again.

70g of oil ash residue is also a max figure obtained from the data and the ECU would consider this 100% full and would no longer allow any regeneration to take place. You would get a warning light on the dash at that point. So the values I use are genuine and not estimated.

I first built an emulator which does a good job of pretending to be my van, and tested it against some industry standard tools, so I know the values are correct, but of course I have a 1.6 and that was the tricky one to do, as the uds codes are not in the public domain. Reverse engineering for many weeks was required to crack that nut.

Finally there is no device I can see which does the same thing in a compact display without using a mobile or android apps and even then, good luck getting the VW 1.6 to work with them (also the most common engine too) as the Simos code is very tightly guarded by Siemens. I haven't seen anything for other vehicle brands either.

The goal was to get a simple display, of live data, constantly on the dash so the user knows exactly what is going on. No fiddling with a mobile app while driving.
Do you happen to know how to translate differential pressure into real soot level? Is there a chart somewhere? My measured soot varies between -7g and 2g... Clearly not right. I'm guessing they might have reset the dpf on the ECU with replacing/cleaning it and so the reference readings is off. I'd love to know what the actual soot level is.
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Re: A wee something to look at...

Post by STP »

The calculated value is the most accurate measure of soot. The "measured" value is almost always negative so is ignored by most developers. The best indication of diff pressure is at idle, since the gas flow is at it's lowest and the pressure difference across the dpf is most accurate too. When the engine is revving, the DPF is always a restriction which gets worse as the gas flow speed rises so the pressure difference gets greater since the gas can only escape at a fixed maximum rate. Increased pressure at the input to the DPF will always result in a higher differential between input and output.

All ECUs calculate these values as there is no sensor to actually measure the weight of a few grams of soot or ash, it's an estimate made by the ECU based on engine load and mileage.
2015 SWB Van, 1.6 CR TDI with Cruise Control, Heated Mirrors, Highline Clocks & MFD, VW Hands Free Bluetooth, Electric Windows, Reversing Cameras, DPF Monitor, Thatcham Cat 2.

My build thread: White MK3 Facelift

My DPF Monitoring Device thread: DPF Monitor
STP
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Re: A wee something to look at...

Post by STP »

stu_b wrote: Tue Jul 08, 2025 9:44 am I am very intrigued by all of this
Would it be transferable to other marques, not just in the VAG group ?
Ie for Mercedes, Fiat, Ford etc etc

Question, and sorry if this is a silly question, but am I right in thinking not all diesels have a dpf ?
Is it dependant on country and emissions etc ?
Also, another silly question, there are a lot of people swapping engine on here n out there
When they swap from one to the other, the vin stays the same but would they have to code in (with the likes of VCDS etc) the new particulars of the new engine so that the system (ECU) can read and diagnose the network of electronics n engine etc etc

I think this is an amazing tool to help the user easily identify your engine management of the DPF system
Thanks mate, that's appreciated.

All vehicles in the EU or subject to the rules hast to have a dpf fitted from 2010/2011 onwards to meet euro 5 standards, and then adblue was mandated from 2016/17 onwards to meet euro 6. This was to control the level of nitrogen dioxide in the exhaust stream. Dpf use was to control pm 2.5 particles from being emitted as they are small enough to lodge deep in the lung tissue and cause health problems. Bigger particles can be washed out by normal lung function but pm 2.5 can't, and stays in there for a lot longer.

If the engine is swapped, I expect they have to move the ECU with the engine, as the control systems and injectors are different. So the VIN will change inside the ECU. Normally they would have to code out the immobiliser or move the clocks, keys and ECU as a set to the new vehicle. So the VIN read from the ECU will change anyway. Not sure how well these vehicles work on a scan tool but most functions will be derived from the VIN they read out from the ECU itself. Other functionality like coding no doubt will be harder to control.

When you call for data from the engine, you use the CAN header 7E0 which tells the system you want data from the engine ECU and only it will answer. Other functionality uses 7DF which means any controller with the data asked for, will respond. Like the central electric module for example if you request UDS data that only it can provide.

The UDS codes and CAN headers I use, only work on VAG group vehicles so other brands wouldn't work, I would have to know the codes or OBD commands for other brands. A lot of regular OBD commands are generic but the other codes such as UDS (unified data systems) codes are specific to a brand and are not generally made public.

Manufacturers charge huge sums to get this info directly from them.
2015 SWB Van, 1.6 CR TDI with Cruise Control, Heated Mirrors, Highline Clocks & MFD, VW Hands Free Bluetooth, Electric Windows, Reversing Cameras, DPF Monitor, Thatcham Cat 2.

My build thread: White MK3 Facelift

My DPF Monitoring Device thread: DPF Monitor
stu_b
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Re: A wee something to look at...

Post by stu_b »

Interesting
I am thinking of this from a business point of view for you, which I'm sure you've given plenty of thought but sometimes the obvious gets overlooked
I am thinking how u can maximize on your investment
Clearly your main focus is on the VW platform but if this was multiversal then you open up more avenues but this may be difficult if the systems are different

I could be wrong, but here in Australia we (were) far behind the 8ball in terms of emissions etc but we have rapidly caught up - hence my asking about dpf and then ad-blue

Thanks for sharing your knowledge
Although still in development stages, have u given much thoughts into commercialisation ?

Even in it's simplicity (I don't mean this in a condescending way) but a garage could buy one of these as a "scan tool" (VERY affordably - compared to other expensive tools) that can be used across many platforms quickly and easily to diagnose dpf status and advise their customer - does this give accurate read out at stationary or does it have to be in motion for an accurate (or more accurate) read out ?
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Re: A wee something to look at...

Post by STP »

The values are read out from the ECU, by asking it for the data you want, and it sends it. The data is encoded and that's another part of the magic, decoding the response. It's a string of hex data and all responses have different mathematical steps required to convert the hex back into the data you need (very very rarely a direct conversion from hex to decimal)

But it could be used for any vehicle in that way with the UDS codes for the brand it is connected to. That also requires reverse engineering the hex responses for that brand.

And yeah the data is accurate regardless of moving or not, as long as the ignition is on.
2015 SWB Van, 1.6 CR TDI with Cruise Control, Heated Mirrors, Highline Clocks & MFD, VW Hands Free Bluetooth, Electric Windows, Reversing Cameras, DPF Monitor, Thatcham Cat 2.

My build thread: White MK3 Facelift

My DPF Monitoring Device thread: DPF Monitor
stu_b
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Re: A wee something to look at...

Post by stu_b »

So at this stage you're primarily doing this for VAG / VW and ultimately for the Caddy

Would this be the same for all VW / VAG or are they all different requiring lots of reverse engineering n coding etc ?
STP
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Re: A wee something to look at...

Post by STP »

No the decoding of the responses will be the same across vag models for the most part, the UDS codes to get the data usually changes with each engine model or generation. So the 1.6 codes are different from the 2.0 but all 1.6 CAYx engine ECUs will use the same codes for example. And later vehicles have more functionality than earlier ones as the electronics get more complex. So more codes are needed.

You can ask the vehicle what functions it supports and it will tell you. Encoded of course!
2015 SWB Van, 1.6 CR TDI with Cruise Control, Heated Mirrors, Highline Clocks & MFD, VW Hands Free Bluetooth, Electric Windows, Reversing Cameras, DPF Monitor, Thatcham Cat 2.

My build thread: White MK3 Facelift

My DPF Monitoring Device thread: DPF Monitor
stu_b
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Re: A wee something to look at...

Post by stu_b »

So would u be able to sell the unit stock as in generic (with or without pre installed specifics) but then be able to customize it via a "patch" for the owner to install via a link ??

This would mean that for each “NEW" patch the hardware would remain the same but the software being run in the dongle would be different n selectable
STP
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Re: A wee something to look at...

Post by STP »

Yeah that is possible, may be an option for the future! ;)
2015 SWB Van, 1.6 CR TDI with Cruise Control, Heated Mirrors, Highline Clocks & MFD, VW Hands Free Bluetooth, Electric Windows, Reversing Cameras, DPF Monitor, Thatcham Cat 2.

My build thread: White MK3 Facelift

My DPF Monitoring Device thread: DPF Monitor
whelp
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Re: A wee something to look at...

Post by whelp »

put me down for one when you're ready to sell them!
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