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Reading DPF values from forscan?


andy1741
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Hi Guys,

I've using the ODBC cable recently with forscan to get a more indepth knowledge of the health of my car. In particular I wanted to read stats on the DPF including the distance to ashful (when i'll have to fork over upwards of €1000 to replace :( ) and tracking the regens. However when I go to forscan, add the PIDs and start recording the DPF values give me nothing. Theres no pressure, 0.0, 100k km to ashfull (assume this is a default value?) and 0.0 since last regen.

 

Is there something I'm missing here? is it my cable? I have an ELM327 cable that I got from my dad. It can read the RPM PID just fine so I assume it is working.. Im just idling in the driveway here as well but I wouldn't have thought I need to be driving to read these values.

 

IMG_1635.JPG

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4 hours ago, andy1741 said:

Theres no pressure, 0.0, 100k km to ashfull (assume this is a default value?) and 0.0 since last regen.

I have not seen that before. Several others have done similar things, all ok.

When Forscan connects, if it asks to load a previous profile, try No, to make it re-scan the system fully.

Those values are possible, they would be seen when idling with a clean DPF (very low DP), and just had a reset learned values, but it is not normal. And the DP should rise if the rpm goes up.

The DTC count is 2, I see, are they relevant at all?

Very odd!

Try monitoring other values like MAP & FRP. It should all work while stationary. If you take it for a drive, do not look at the display while moving (obviously)! Use the logging mode, then stop, stop logging & save the recorded values.

If all else fails, try another ELM. Wireless ones are notorious for problems, USB is much better if you can use it.

 

 

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6 hours ago, Tdci-Peter said:

Those values are possible, they would be seen when idling with a clean DPF (very low DP), and just had a reset learned values, but it is not normal. And the DP should rise if the rpm goes up.

The DP definitely did not rise with RPM, I revved to about 2.5k and no change. Not for very long though just 15-20seconds.

6 hours ago, Tdci-Peter said:

The DTC count is 2, I see, are they relevant at all?

The DTC codes are two to do with low fuel pressure caused by a clogged fuel filter. I'll be changing the filter this weekend so I think theses are irrelevant,

6 hours ago, Tdci-Peter said:

If all else fails, try another ELM. Wireless ones are notorious for problems, USB is much better if you can use it.

The one im using is wired usb.

I'll try keep the logging when going out for a drive and see if I can spot anything.

I bought the car 3k miles ago at 110k miles and I dont know much of the history before that only that it was regularly serviced but no details on what was changed/serviced. I would assume that the car would be very close to ashful at this stage? Because it is still running would that indicate that the DPF has been replaced at some point? Also could these values indicate there has been a DPF delete?

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Andrea, just a suggestion, and to anyone else who takes a photo that's rotated, you can correct it before sending by viewing it in Windows Photo Viewer. Rotate it to the correct orientation. When you exit the viewer it will save it in that state. On an Android phone you can rotate it in the Gallery.

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I would hazard a guess your dpf has been gutted and mapped out.

Hence why you are getting no readings at all. It's as if the ashful figure has been reset and turned off in effect.

Have you ever noticed the car doing a regeneration?

I think mine has been gutted as I get less that 1kpa while idling as low as 0.2 and the highest I have ever seen is 1.2kpa way lower than even people who have fitted a brand new DPF.

What's the pre filter temperature like on a long run? 

If the Senor's were not working correctly then Regen's are unlikely to happen and the filter will soon fill up with soot and won't be burned off.

What's the exhaust tailpipe like? Mine was immaculate when I got OT no soot at all, then I noticed it start getting sorted up after it had the glow plugs done at the garage I bought it from when I suspect they may have gutted the dpf at the same time, as he was saying if I had any more issues with the dpf he would remove it and get it mapped out.

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5 hours ago, andy1741 said:

Also could these values indicate there has been a DPF delete?

That is what Simon (above) thinks, and he could well be right.

One of the driving forces for the international OBD2 standard & its enforcement was to be able to check up on emissions kit. Parts of the USA, and possibly parts of Europe do this. This is from a DMV site in Nevada, USA:

" Your yearly smog check on 1996 and newer vehicles is done through OBD II, rather than the older two-speed or "tail pipe" test. OBD II is more accurate than the two-speed test and less costly than the dynamometer tests used in some other states. The test itself is also much faster. Stations can often complete an OBD II test in five minutes or less. "

The UK does not do that, just the old "tail pipe" test. I have not heard of plans to change this, it could cause a lot of problems if it was to change.

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23 hours ago, simcor said:

I would hazard a guess your dpf has been gutted and mapped out.

I would love if this was the case... The car has just passed NCT so no issues with that and emissions. I also would not have worry about short trip journeys.

23 hours ago, simcor said:

Have you ever noticed the car doing a regeneration?

No I have never actually noticed this. I just assumed it happened and that I wouldn't feel it. Can the driver tell if the car is doing a regeneration? is it obvious?

 

On 23/9/2016 at 11:54 AM, simcor said:

What's the exhaust tailpipe like?

The exhaust is filthy. Very sooty. I even cleaned it with some paper towel the last time I cleaned my car, after the next time I drove the car it was covered in soot again. I had put this down to the fact that most diesel cars seem to have dirty exhaust pipes.

Could anyone answer a few DPF questions? The DPFs have an ashful figure,  is this just a mileage figure similar to a timing belt i.e. it must be replaced after a certain mileage? If so what is this mileage? at 113k miles would it be expected that the dpf has been replaced in the past regardless of the driving style of the previous owner?

 

I would love if the DPF had been gutted and remaped however I'm not convinced because im not getting any pressure reading at all. To me this says that either the sensor is broken or my tool cannot read this. I'll record a 10 mile trip today and see if the pressure figure changes from 0.0 at any point.

Normally when people plug the cable in and record, say the distance from last regen do the immediately get the figure?

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A working DPF should leave an almost perfectly clean tail pipe. The soot should be caught and burned and turned to ash.

As for noticing a Regen the car should feel a bit sluggish at pulling off and the fan should be on and you should hear the fan when turning the engine off whilst doing a Regen, you should also have some visible smoke from the exhaust when coming off the throttle and should disappear when accelerating again.

If it has been mapped out then I would expect no figures as the ECU has had those PID'S removed or altered to basically not send any info to the ECU.

I would say it most likely has been gutted and mapped out in my opinion.

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75K miles for the earlier additive DPF and I think 120K for the coated DPF system from memory.

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11 hours ago, andy1741 said:

The DPFs have an ashful figure,  is this just a mileage figure similar to a timing belt i.e. it must be replaced after a certain mileage?

I have heard of that ASHFUL figure jumping down by quite big steps, and counting up (the wrong way). It must be an estimate made by the pcm software, based on DP readings read from the DP sensor. So, no it is not just a mileage count.

I am pretty sure all the DPF OBD figures work ok with the car stationary & engine running.

Soot in the exhaust is a big clue!

 

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9 hours ago, simcor said:

A working DPF should leave an almost perfectly clean tail pipe. The soot should be caught and burned and turned to ash.

As for noticing a Regen the car should feel a bit sluggish at pulling off and the fan should be on and you should hear the fan when turning the engine off whilst doing a Regen, you should also have some visible smoke from the exhaust when coming off the throttle and should disappear when accelerating again.

This is definitely not the case for the tail pipe. The Regen seems to be something I could have missed without a trained eye but at the same time maybe I would notice and have just never had one.

I took the car out for a 30 mile trip today and recorded the whole journey. ashful, dpf pressure and distance from last regen didnt change once, while speed, rpm etc all recorded correctly. This to me points that these PIDs have been altered with.

This leaves me with two questions then. First, has anyone ever encountered a scenrio where the odbc cable would be a limiting factor here? For example is there certain cables that would be able to read the RPM but not the DPF values? Is it an all or nothing situation? would forscan even show these PIDs if they could not be read by the cable?

Second, Is there any other way to tell if the DPF has been modified? Only way I can think of is to take the heatsheild off and tap on it. If it has been gutted it would surely make a noticeable hollow sound. This seems like a lot of effort though.

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Remove the heat shield and look for non OEM weld marks on the DPF filter canister, that would indicate it is has been gutted.

My exhaust tail pipe was very clean when I got it. no soot build up at all, after it went back with glow plugs fault and he suggested any more issue bring it back for DPF removal was when I started noticing soot build up on the tail pipe.

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Thanks Simon I'll give this a go next weekend when I have a bit of time. As a side question, what are the possible damages someone can get from driving a diesel car only on short trips? would it just be clogging the DPF and the EGR?

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The main issues are DPF and EGR issues and turbo worries, carbon buildup can also cause turbo oil starvation, most of these things can be avoided with some prevention techniques and regular servicing etc.

Short journeys for any car no matter what fuel are never that good and can be more problematic than higher mileage cars that have done a lot of long distance journeys.

Diesel engines tend to be more bullet proof than petrol engines even with DPF and DMF's etc, the problem is the more complex they get the more expensive issues there are to go wrong with them, even some newer petrol's are getting similar as most cars nowadays have DPF's and small capacity turbo's etc

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Yeah this makes sense. Simon as a side note recently I've been trying to diagnose and fix a DTC in the FACM in my car, P2409-60 Fuel cap sensor/switch circuit range or performance. I made a thread here:

 However it just occured to me that the magnet in the fuel filler flap may have been intentionally removed by the previous owner after a dpf gutting. This would break the circuit and stop the FACM injecting eolys into the fuel tank. Obviously because eolys is not needed without a DPF. If your car's dpf has indeed been gutted this might be something to look into as you could be wasting money by injecting eolys. I've seen quotes for a eolys refill job for 200-300€, definitely no point in paying this if you dont have a DPF. However I'm not sure if eolys has other useful properties that would be usual to keep around.

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I don't think removing the magnet would make any difference all that seems to do is a counter of how often the vehicle has been fuelled up. I believe the FACM needs mapping out too if it is done properly.

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2 hours ago, andy1741 said:

This would break the circuit and stop the FACM injecting eolys into the fuel tank. Obviously because eolys is not needed without a DPF.

It makes more sense now. The flap counter will eventually signal tank empty, with warning lights & probably limp mode if ignored. No Eolys is deadly to DPFs. If no Eolys is needed, freeze the count to prevent that.

There seems to be no Eolys level detector on the Ford dosing system, it all relies on counting measured doses.

 

On 25/09/2016 at 2:53 AM, andy1741 said:

For example is there certain cables that would be able to read the RPM but not the DPF values? Is it an all or nothing situation? would forscan even show these PIDs if they could not be read by the cable?

Second, Is there any other way to tell if the DPF has been modified?

I do not think a cable problem is likely here. PIDs are just locations in the modules' memory, so should not vary, and they are being read, just indicate zero.

I would investigate the DP from the DPF. For 2 reasons:

1 A very low reading would indicate a hole in the core or no core (a hole is sufficient, and ingenious mechanics could do this via a port).

2 A very high reading would indicate the DPF has been mapped out, or the DP sensor is faulty, but the core is present & badly blocked. This would affect the performance & economy of the car. If you have only had the car for 3k, this could just be a problem waiting to happen. A cheapskate, bad seller could have disabled the DPF by software to hide an error code (very cheap & quick if you know how already), and not done anything to the dpf itself.

A longish piece of transparent tube could be made into a U tube manometer, by taping it to a bit of wood. It needs to be at least 1.5m high. 1kPa = 102mm height difference of water levels. Either locate the DP sensor, disconnect the hoses there & link on the manometer tube, or do it at the DPF. (The DP sensor output voltage could be used, but relies on it working, & knowing what its calibration is.)

Scenario 2 is unlikely due to the soot in the exhaust, but may still be worth checking.

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9 hours ago, Tdci-Peter said:

2 A very high reading would indicate the DPF has been mapped out, or the DP sensor is faulty, but the core is present & badly blocked. This would affect the performance & economy of the car. If you have only had the car for 3k, this could just be a problem waiting to happen. A cheapskate, bad seller could have disabled the DPF by software to hide an error code (very cheap & quick if you know how already), and not done anything to the dpf itself.

This could well be the case. I will be taking the heat shield off this weekend and investigating for weld marks etc. Its hard to tell if I am getting 100% of the power I should be. This is most powerful car I have ever owned (only owned a 1.0 and 1.2 petrol car before). However, the power has not decreased at all in the time I have owned the car and it feels like a lot of power. The fuel economy has also been steady since owning the car. I get 45mpg city driving and 70+mpg on motorway (often 90+ at steady speed on the motorway). From what I have seen online these are expected figures.

 

However I agree that this could be ticking time bomb. The dealer could have easily know that the DPF was screwed on this car and simply disabled the PIDs meaning the car would hopefully not go into limp mode while in the warranty period (ended mid August) and hence it would be my problem after. Potentially the DPF could be dying very soon and the only reason it is still alive is the passive regen from the couple of 200 mile trips I've taken.

I think scenario 1 is much more likely due to a number of factors (including my bias!). The soot in the exhaust, this appears in the exhaust after a single trip and is noticeably sootier than most diesels or cars in general. The missing magnet in the fuel filler cap may not be red herring. Not just the DP PID not working, all DPF PIDs do not work. Maintained power/ fuel economy while the DPF has not been regenerated in 3k miles. The dealer was a SIMI dealer, the highest standard in Ireland and it is unlikely that he would have done something malicious (however he may not have done anything and be completely unaware even though he is accountable).

To me this points completely in the scenario 1 direction but as they say the proof is in the pudding and the only way to tell is if I inspect the DPF and find concrete evidence.

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  • 11 months later...

Hi Andy,

Did you get to the bottom of this in end?

I have similar but slightly different problem in that I'm not getting any differential pressure readings (see image - the other PIDs were to make sure I was getting something reading) but I have a a P2002-C and P2002-E1 error codes with a MIL.

I'm thinking it could be the differential pressure sensor that has gone (or the hoses from the DPF to sensor) and was hoping to measure the voltages from it tonight but it's pouring so that will wait till tomorrow.

I use the Android version and I don't think I can see the Ashful and Distance since Regen PIDs.

Screenshot_20170904-190241.png

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