Trouble with HDi additive system (DPF system)

[Klinto75m]

Hello

Not long ago I switched out my beaten 406 for a 1 year newer one (with 200k less km on the clock).
But with the change came the addition of the DFP system. I'm in the progress of clearing all the fault codes, and these are the only ones left.

The car is:
Model: Peugeot 406 st.
Motor: 2.0HDi RHS
Year: 2002

I've attached a photo, but probably not very useful as it's in danish, I'll do my best to translate.

- Permanent fault: Signal for min additive level
- Permanent fault: Additive pump
- Periodic fault: Management of injector (?)

I have not done much troubleshooting yet, but here is what I've done
- Used a feature in Delphi diagnostics to test additive pump, pump didn't start
- Checked the level of additive fluid (haven't measured, but around 1/2 - 3/4 tank)
- I've dismounted the DPF and cleaned it thoroughly with water

Troubleshooting I can think of but haven't done yet
- Remove the plug from the additive pump, and try with a 12v battery to activate the pump. (From a diagram i found, it seems like pin 3 is positive, and pin 4 is negative

Would appreciate a place to start, as I'm a little lost with DPF systems as it's the first car I own with one.

[Doggy]

In the UK, DPF systems were only ever fitted to 2.2 HDi 406 models, so this is very unusual for us.

I guess your car ran out of fluid at some point and was not refilled quickly enough.

A false low additive signal is fairly common due to the strange way the level detector worked. It measured the current flow through a thermistor that is normally immersed in the fluid, keeping it cool. The temperature rise / resistance change when the thermistor is no longer covered in fluid triggers the low fluid alarm. It is not unusual for the thermistor to fail when the fluid level is low.

It may be that the pump would also fail eventually with an empty tank

For me, the simplest solution was to remove the DPF and adjust the ecu map to work without it. In then UK, cars built before 2008, (I think), do not have to pass the same emission test as later vehicles, so this is not a problem.

If your car has a Bosch EDC15 ecu, it can be reprogrammed via the diagnostic socket to completely ignore the DPF system.

Have a look at this: viewtopic.php?f=10&t=12487

[GingerMagic]

I'm sure there were a handful of 2.0Hdi with the DPF but I thought that was the very last ones off the production line... ( Didn't Sam have one of them..?)

I would certainly just remove or bypass the DPF, you could fit an earlier non DPF exhaust section which should be readily available online etc.

Then, as Doggy has suggested, you could have the ECU flashed ( remapped basically ) via the obd port and a flashing tool, or remove your ECU and send it off to a specialist company like BBA Reman, or PSA....

Alternatively, if you are on a budget, just beat out the internals of the DPF and drive the car as is. It should run fine but you may still get the warning bongs which could be problematic come MOT time.

[Klinto75m]

In the UK, DPF systems were only ever fitted to 2.2 HDi 406 models, so this is very unusual for us.

I guess your car ran out of fluid at some point and was not refilled quickly enough.

A false low additive signal is fairly common due to the strange way the level detector worked. It measured the current flow through a thermistor that is normally immersed in the fluid, keeping it cool. The temperature rise / resistance change when the thermistor is no longer covered in fluid triggers the low fluid alarm. It is not unusual for the thermistor to fail when the fluid level is low.

It may be that the pump would also fail eventually with an empty tank

For me, the simplest solution was to remove the DPF and adjust the ecu map to work without it. In then UK, cars built before 2008, (I think), do not have to pass the same emission test as later vehicles, so this is not a problem.

If your car has a Bosch EDC15 ecu, it can be reprogrammed via the diagnostic socket to completely ignore the DPF system.

Have a look at this: viewtopic.php?f=10&t=12487

I want to avoid the solution involving a DPF delete.
The reason is, that the government is beginning to make "environmental zones" in the center of some of the larger cities. This means that diesel cars must be fitted with a DPF to drive inside the zone. For now, it's only commercial vehicles that are targeted. But I don't think I'll be many years before the same law applies for personal vehicles.

But what you wrote beside is interesting. It gives me some point of failures to look for, to determine the origin of the fault.
- Measure the resistor for the right resistance (dunno if this can be found in Haynes etc.)
- Measure if the additive controller, are sending a signal down to the pump

I'm not sure either it many of the danish models was fitted with a DPF, as I haven't seen one with it, at my local scrapyard. (I mostly only see gas models)

[GingerMagic]

Ah, okay

I'm not sure about the Euro class on a 2002 , I would assume it's a Euro4 - even my 2013 DAF is only a Euro5.

As a temporary fix, you can remove the DPF cannister from the car, then pressure wash the insides to clear out any potential blockages, then refit once dried out.

Or, using PP2K, you can do a 'Force Regen', although I've never found it to be a useful method.

This will give you a little piece of mind that there is no back pressure in the exhaust system - then you can tackle the other issues.

[Doggy]

As far as I can remember, the connector has 2 pins for the pump motor and 2 for the thermistor. If the thermistor is faulty it will be open circuit.

I ran my car with the dpf removed and no software changes for perhaps 3 months before the engine management light came on and the car went into limp mode. When I was able to check with PP2000, I found several error messages, all related to the additive system. I do not know if it would have been possible to just clear these faults and restore normal operation, I did not try to do that.

I understand your desire to retain the dpf, but you must recognise this system is one of the earliest and least reliable examples of additive assisted particle filters. Cleaning the dpf off the car will prevent it blocking for a time, but without successful regenerations it will block again. How long it takes depends on how you drive it. It may be OK for a long time if you are able to mostly avoid idling and short journeys.

A second dpf unit could allow you to quickly swap them over.

Another possibility would be to swap between your current set up and an empty dpf canister/modified ecu map and back again - this would cost very little, (assuming you can find a another dpf), and give you time to resolve your additive system problems.

If you can find a scrap vehicle, I would collect the dpf, differential pressure sensor, additive tank, additive injector from the main fuel tank, the fuel filler sensor etc. and the additive ecu.

I think your car will have been built roughly to Euro 4 specification, but BEFORE Euro 4 was finalised prior to its introduction in 2005 for vehicles registered from 2006. I believe the PSA DPF system was launched with the 2.2 DW12 engine in 1999/2000. In other words, it may not be compliant even if you get it fully working.

[Klinto75m]

Ah, okay

I'm not sure about the Euro class on a 2002 , I would assume it's a Euro4 - even my 2013 DAF is only a Euro5.

As a temporary fix, you can remove the DPF cannister from the car, then pressure wash the insides to clear out any potential blockages, then refit once dried out.

Or, using PP2K, you can do a 'Force Regen', although I've never found it to be a useful method.

This will give you a little piece of mind that there is no back pressure in the exhaust system - then you can tackle the other issues.

I've already cleaned out the DPF with water (and a lot came out). Did it till the point where I couldn't see anymore coming out, about 30-45min. And I've run a Force Regen.

I'm not sure which Euro class it is, I'll let you know later when I'm getting to work on it.

As far as I can remember, the connector has 2 pins for the pump motor and 2 for the thermistor. If the thermistor is faulty it will be open circuit.

I ran my car with the dpf removed and no software changes for perhaps 3 months before the engine management light came on and the car went into limp mode. When I was able to check with PP2000, I found several error messages, all related to the additive system. I do not know if it would have been possible to just clear these faults and restore normal operation, I did not try to do that.

I understand your desire to retain the dpf, but you must recognise this system is one of the earliest and least reliable examples of additive assisted particle filters. Cleaning the dpf off the car will prevent it blocking for a time, but without successful regenerations it will block again. How long it takes depends on how you drive it. It may be OK for a long time if you are able to mostly avoid idling and short journeys.

A second dpf unit could allow you to quickly swap them over.

Another possibility would be to swap between your current set up and an empty dpf canister/modified ecu map and back again - this would cost very little, (assuming you can find a another dpf), and give you time to resolve your additive system problems.

If you can find a scrap vehicle, I would collect the dpf, differential pressure sensor, additive tank, additive injector from the main fuel tank, the fuel filler sensor etc. and the additive ecu.

I think your car will have been built roughly to Euro 4 specification, but BEFORE Euro 4 was finalised prior to its introduction in 2005 for vehicles registered from 2006. I believe the PSA DPF system was launched with the 2.2 DW12 engine in 1999/2000. In other words, it may not be compliant even if you get it fully working.

I can understand that the early development of the DPF system is not particularly reliable. But nonetheless, I would like to see it work again. My driving has changed a lot since Covid, but some shorter journeys of 14-24km are not unlikely. But mostly I'll take at least 80-100km trip each week.

Keeping a spare DPF system could be a very good way to ensure there is not a blockage, and it is working. Do you know if the same DPF system is fitted to other Peugeots as well? Haven't seen a single 406 with the DPF system at the scrappers I go to. Just generally not many diesel I see.

For the troubleshooting, I'll get onto it today. By open circuit do you mean, if i Ohm trough the resistor there should be no signal going through? or just a very high resistance?

[Doggy]

This link https://catalogs.ssg.asia/peugeot/?lang ... vzxPtKL8cU
should let you check the part number for your dpf and find out which other Peugeot / Citroen models it was fitted to.

By open circuit, I mean no connection / infinite resistance.

Do you know if your forced regeneration was successful?
I think it will not work unless the additive system is OK - the soot will burn off at 450 degrees+ WITH additive, but needs >500 degrees without.

[Klinto75m]

This link https://catalogs.ssg.asia/peugeot/?lang ... vzxPtKL8cU
should let you check the part number for your dpf and find out which other Peugeot / Citroen models it was fitted to.

By open circuit, I mean no connection / infinite resistance.

Do you know if your forced regeneration was successful?
I think it will not work unless the additive system is OK - the soot will burn off at 450 degrees+ WITH additive, but needs >500 degrees without.

That's actually a very good point. If there is no additive in the diesel, it wouldn't be hot enough. I thought about manual dosing, but from my understanding, the system won't do regens on its own with faults on the system.

The parts catalog is a helpful feature I'll keep in mind.

I've just done some troubleshooting on the car:

When reading the voltage coming to the pump (From additive comp -> pump connector plug). It reads 3.2v no what.
I tried via Delphi diagnostic tool, to do a component check on the additive pump. Voltage didn't change.
If it doesn't change the voltage when activating the pump, I might be looking at a new additive computer?

Measure the resistance on the resistor, and as you said. There was an open circuit, so the resistor is toast.
Can you change the pump/resistor assembly separately, or are they sealed into the tank?

[Doggy]

I have never changed any parts of the additive system so do not know whether it is possible to change the pump and/or level sensor. I suspect your best option would be to find a complete assembly from a scrap car, but I appreciate there is a risk the replacement could be faulty too.

It may be worth checking if the parts you need are the same as the 2.2HDi, (the dpf unit looks identical). Adrian Bingham is or at least was a specialist breaker in the UK who concentrated on the 406 coupe at one time. Try https://www.ebay.co.uk/str/bbautos

I think you would have more success with a Lexia 3/PP2000 setup, I think you will need it to reset the counters etc after refilling your additive tank, plus it will give you better diagnostic information.

[Klinto75m]

I have never changed any parts of the additive system so do not know whether it is possible to change the pump and/or level sensor. I suspect your best option would be to find a complete assembly from a scrap car, but I appreciate there is a risk the replacement could be faulty too.

It may be worth checking if the parts you need are the same as the 2.2HDi, (the dpf unit looks identical). Adrian Bingham is or at least was a specialist breaker in the UK who concentrated on the 406 coupe at one time. Try https://www.ebay.co.uk/str/bbautos

I think you would have more success with a Lexia 3/PP2000 setup, I think you will need it to reset the counters etc after refilling your additive tank, plus it will give you better diagnostic information.

I have a pp2000 interface. It just didn't have the feature to test the pump (or I couldn't find it ). If I can find another donor car, that would probably be my best option.

Unfortunately buying spare parts from the UK might be costly, since I would need to pay customs.

I thought about manual dosing and manual regen until I can find the required parts. Do you know approx how many km between manual regen? and how much additive it squirts into the tank when filling up.

[Doggy]

It's a long time since I looked at this system on a 406, but I remember reading that the maximum interval between regens was about 500km with a clean filter, (i.e. everything reset to as new condition). The interval reduces as the calculated soot loading increases, getting as low as <100km when it 'thinks' the filter is nearly blocked. I have no idea what the injection quantities are.

This link may help: http://www.citroenet.org.uk/passenger-c ... tech3.html

Back in 2008/9, I was able to find a PSA training document with a lot more detail, but I cannot find any deference to it now. I gave up studying the system when a simple method to remove it became available in 2009

With PP2000, I was able to find the upstream and downstream temperatures, (but in different parameter sets). There was a dedicated page for dpf condition somewhere, with numbers for distance since last regen, number of failed regens, some measure for dpf contamination, (% I think), fluid remaining etc. There is also a semi-guided procedure for refilling the tank, resetting counters etc.

Not sure how I found it, but I think it appears in the ecu/system list for a global test. Failing that try searching by function for any option that suggests dpf/additive/emission control

[Klinto75m]

It's a long time since I looked at this system on a 406, but I remember reading that the maximum interval between regens was about 500km with a clean filter, (i.e. everything reset to as new condition). The interval reduces as the calculated soot loading increases, getting as low as <100km when it 'thinks' the filter is nearly blocked. I have no idea what the injection quantities are.

This link may help: http://www.citroenet.org.uk/passenger-c ... tech3.html

Back in 2008/9, I was able to find a PSA training document with a lot more detail, but I cannot find any deference to it now. I gave up studying the system when a simple method to remove it became available in 2009

With PP2000, I was able to find the upstream and downstream temperatures, (but in different parameter sets). There was a dedicated page for dpf condition somewhere, with numbers for distance since last regen, number of failed regens, some measure for dpf contamination, (% I think), fluid remaining etc. There is also a semi-guided procedure for refilling the tank, resetting counters etc.

Not sure how I found it, but I think it appears in the ecu/system list for a global test. Failing that try searching by function for any option that suggests dpf/additive/emission control

I've thought about the partial DPF delete.
So only the particle filter itself is removed. And the additive tank etc. is kept on.

Is it possible to "remap" it by adjusting some settings in pp2000 or, do you need some tuning shop to do it for you?

My plan was to remove the filter when driving, and whenever I had to get it through MOT I would just put on the filter, and remove it again.

[Doggy]

Yes, it's perfectly possible to swap the dpf for an empty casing and then back again at MOT time.

All of the following assumes you have a Bosch EDC15 ecu.

You need an ecu flash programmer to read your existing ecu map and write the modified one to the car. I use a Galleto 1260 which is easy/cheap to get on eBAY etc. (Other programmers are available, but this is the only one I have experience using).

If you PM me, I will explain how to send me the file for modification/return

I suggest only changing the ecu map once - I would leave the additive system disabled when using the 'real' DPF, it will be OK without regenerating for a week or two while you get your MOT, even if you need a retest after any failure repairs. This avoids the risk of engine management light and/or additive/antipollution fault messages affecting the MOT.

[Klinto75m]

Yes, it's perfectly possible to swap the dpf for an empty casing and then back again at MOT time.

All of the following assumes you have a Bosch EDC15 ecu.

You need an ecu flash programmer to read your existing ecu map and write the modified one to the car. I use a Galleto 1260 which is easy/cheap to get on eBAY etc. (Other programmers are available, but this is the only one I have experience using).

If you PM me, I will explain how to send me the file for modification/return

I suggest only changing the ecu map once - I would leave the additive system disabled when using the 'real' DPF, it will be OK without regenerating for a week or two while you get your MOT, even if you need a retest after any failure repairs. This avoids the risk of engine management light and/or additive/antipollution fault messages affecting the MOT.

Thanks, that's very helpful . I'll order an ecu flash programmer next month, and let you know when I'm ready for a little guidance.