Euro 4 D5 - VNT motor issues, and odd Soot Filter warning

foggyjames · Aug 10th, 2021, 01:26

Hi All,

I've been working on my friend's Euro 4 D5 recently. I told her not to buy a Euro 4 - the runt of the 5-cylinder litter, in my humble opinion, but was I listened to...? She's had it for 3-4 years, and it's been in some level of limp-home state or otherwise misbehaving for most of that time. It has further reinforced my already low opinion of Euro 4s, frankly. I don't get much chance to work on it, but when I do it just seems to be never-ending - fix one problem (or even just see light at the end of the tunnel) and another appears. There's a long story of other things done in the pursuit of making it right (including the swirl flap assembly and arm), but the relevant info is as follows...

It was making a noise like it had a boost leak (but I eventually pressure tested as much of the system as I could, and couldn't find anything leaking), and would go 'flat' (like a temporary limp-home) if taken over about 2500rpm at full throttle. If you tried hard enough, you could make it enter limp-home mode properly, with a Engine System Service Required message and a boost control code. Eventually we realised that the VNT motor wasn't moving. My hunch is that the "boost leak" noise is a strange acoustic effect due to the VNT being in the wrong position. This was removed and stripped, and the internal cog was found to be stripped (in the middle, not at either end). The mechanism on the turbo itself appears to be perfectly free, which is odd, especially with the cog wear being in the middle.

A friend sold me a motor from a P2 Euro 4 D5, but when we came to fit it, the actuator arm was fitted almost exactly rotated by 180 degrees. This was removed, rotated by 180 degrees, and welded back into position. This motor worked but would only report a range of movement in VIDA of 0.5% to 65% - is that normal, or would something close to 0-100% be expected? With hindsight, I should have investigated further and measured more carefully before rotating the arm, but my memory is that both cog-sets were resting in the middle of their travel, so a 180 degree rotation seemed fair enough. I thought self-calibration (there's an integral position sensor) would take care of any minor inaccuracy. Probably wishful thinking, with hindsight, but not a lot to lose, with the old motor being dead.

Further research revealed that there were quite a few different motors fitted to D5s. We're going to get the correct one and try again, naturally, but it would be interesting to know about the range of movement question, as posed above.

The new motor moved, but the car was much more limp-homey than before (code ECM-P029900 (Underboost) stored - predictably, if the VNT can't reach the commanded position). It appeared to have a certain amount of go - possibly similar to before. It was certainly driveable if you weren't in a hurry. I assume the VNT was stuck in a mid-position previously, therefore the turbo was able to operate to an extent, albeit with extra lag, and a tendency to overboost and have to be reigned in by the ECU, presumably via fuel cut. It also stored ECM-P004500 (VNT Solenoid open-circuit), although I've slightly lost track of exactly when that appeared. I tried putting the old motor PCB on the new motor, as there is clearly some considerable control electronics inside the motor, and I thought it was possible that the motor could be commanded to run in the opposite direction (given the angle of the actuator arm), or somehow be coded, or talk a subtly different language (in terms of its commands from the ECM) to the earlier motor. The original PCB would move the (new) motor, but only when first plugged in, or when putting the ignition on. It wouldn't move under any other circumstances. Very odd. The complete new motor would seemingly respond normally (aside from the "65% question").

Continuing with the test drive, however...push it too far (not actually far at all...) and it would enter a further stage of limp-home, which left it severely lacking power. Not really usable except at city speeds, or in an emergency for longer runs. I think this "stage 2 limp-home" was triggered by issue 2...

Sigh. The second issue appeared on the first drive after fitting the new motor (and no sign of it before, the car mostly living on motorways, etc). "Soot Filter Full" and codes ECM-P245202 (DPF differential pressure sensor general signal failure) and ECM-P242F85 (DPF restriction - ash accumulation - bus signal / message failures - signal above allowable range). The explanation for neither fault is exactly...detailed...!

I did a bit of a datalog, and the pressure differential reading was staying stable. The recorded soot level is 22.65g, which VIDA suggest will trigger a "normal" re-gen (and not a limp-home condition!). Pressure at idle was 19hPa (which VIDA says is normal) and maybe 23 when driving (it was pretty much constant). So very slightly high, but I would maybe expect a re-gen, not a fault code and severe limp-home.

As far as I can see, neither value should trigger a fault. Sounds more like a spurious reading to me, but nothing was appearing on the datalog (even when the code was triggered). So...DPF experts...what do you think? Could the VNT issue have upset the DPF differential pressure sensor somehow? It will clearly have an effect on exhaust pressure! I am very confident that we didn't disturb the wiring when fitting the VNT motor (which would be an obvious explanation). The timing seems far too much of a coincidence to be entirely unrelated though. The triggering of the DPF codes appears to be load-related. It only really happens when accelerating above say 35mph.

Long post, I know. In summary, two questions:
1) What is the normal range of reported VNT motor movement - 0-65%, or 0-100% (ish)?
2) What would cause a seemingly correctly-functioning DPF to trigger a limp-home condition (and the reported codes)?

As you can probably tell, this is not my first rodeo, but what I am struggling for here is knowledge of the specific quirks of the Euro 4. I am reasonably confident that the boost codes will go away with new/correct VNT motor, but I am worried about this DPF business...and it's getting to be more than anyone's nerves can take!

All thoughts greatly appreciated...!

cheers

James

Moussey · Aug 11th, 2021, 09:41

Morning, I have intermittent hesitation/ limp mode issues as well so like to help. Car is a 2009 2.4D

I just fired up my car scanner app, not Vida I know but so much easier to use.

When idling "Turbo bypass or VNT" runs at 95%. When pulling against the brakes with boost unto 100 odd kpa it goes to 100%. If you blip it then on the overrun it goes down to 30% ish. When the engine is killed
it drops back to 0% after about 5-8 seconds and makes a noise like a muntjac barking if you know what that's like. I'd always wondered what the noise was so am really chuffed to have found out.

Hope that helps, I do appreciate that my generic scanner %s may not map to Vida but given the ranges it seems they do should.

The car is on ramps at the moment and I will be road testing to see if I can pin point the hesitation.

foggyjames · Aug 11th, 2021, 18:26

Many thanks for the info! I agree that it's not 100% conclusive, because VIDA and your scanner might express things differently, but it holds some promise.

Have you got any codes stored which might explain your hesitation issue, out of interest?

(EDIT: My friend's car is actually a 2.4D, too, but given that the only difference I'm aware of is software, I thought it was easier to just call it a D5. It was mapped at one point, but we had it removed after the clutch started slipping)

cheers

James

cheshired5 · Aug 11th, 2021, 20:27

I don't know about the turbo issue as I would just fit whatever should be fitted and not get involved in making something else work.

My friend's Euro 4 had been having DPF sensor codes and limp mode and I fixed it with a new fuel filter and new glow plugs as they are used for the regeneration process.

Fitting a new DPF Pressure Sensor made no difference. I told him it probably wouldn't but he wanted to try as it was cheap and easy to replace.

Basically, test all 5 glow plugs and replace the the fuel filter as there's no mention of either above.

The Euro 4 is pretty decent but needs absolute basics covering before over thinking problems which I suppose is just like any engine.

VNT positions are in Vida in Diagnostics >Vehicle Communication >ECM >Parameters >Description

foggyjames · Aug 11th, 2021, 22:51

Many thanks for your thoughts. A few notes...

Quote:

Originally Posted by cheshired5

I don't know about the turbo issue as I would just fit whatever should be fitted and not get involved in making something else work.

At the risk of stating the obvious, I entirely agree, and that's the plan. As it was, on the day, I realised we had the wrong part, and tried to make the best of the situation. I don't get that many opportunities to work on the car, and we turned up with no VNT control at all, so I thought "how much worse can we make it...?". Silly me, obviously...! I am thinking / hoping that the correct motor will make the boost control problem go away (and quite possibly the DPF sensor issue, too).

Quote:

Originally Posted by cheshired5

My friend's Euro 4 had been having DPF sensor codes and limp mode and I fixed it with a new fuel filter and new glow plugs as they are used for the regeneration process.

The fuel filter is recent, but it has thrown codes for a couple of glow plugs. Interesting. I will get on that...

Quote:

Originally Posted by cheshired5

The Euro 4 is pretty decent but needs absolute basics covering before over thinking problems which I suppose is just like any engine.

This car has given significantly more problems than the Euro 3s or 5s I've dealt with, if we ignore the Bosch CP4 issues on the Euro 5s. I think they rushed the development - the fuel-in-oil re-gen issues are well documented, etc, and don't seem to affect the later cars. Admittedly hers doesn't seem to suffer from that, so maybe they refined the software.

I appreciate that I put a *lot* of text up there, but I'd just to emphasise the point that we went from no DPF codes to full limp-home immediately after swapping the VNT motor. No time for it to get full of soot (and the pressure / soot mass readings appear to support that, and suggest that the issue is being triggered by something spurious - would you agree?). I know it's dangerous to assume, but it feels a lot like cause and effect to me...I just can't work out why!

The only other thing I can think of worthy of mentioning is that this car appears to have occasional weird "wiring loom" issues, like being prone to conking out if driven thrown a large/long puddle (the sort which might make you go "weeeeeeeee!" as you drive through it, and risk drenching and nearby pedestrians

). So there is always a chance that it's related to that.

But yes, first port of call will be to fit the correct VNT motor and investigate the glow plugs.

Quote:

Originally Posted by cheshired5

VNT positions are in Vida in Diagnostics >Vehicle Communication >ECM >Parameters >Description

Thanks! I find the location of some information in VIDA quite obtuse. I'd totally missed that. For anyone else reading this, it says the following:
At idle: 55-70%
Ignition on: 80-90%
Measurement range: 0-100%

I think what I was recording was the reported values when doing a manual activation (Diagnostics >Vehicle Communication >ECM >Activations), so there's still a chance that's only supposed to go to 65%...but I guess we'll find out when we fit the new motor!

cheers

James

Moussey · Aug 13th, 2021, 08:35

Happy to have hopefully helped.

I only have the PO428 DTC but I drove it yesterday. The cat #2 temp sensor and the DPF temp sensor ( Think they are the same thing) breaks down when it gets warm and the car goes into limp mode. If driven slowly, or stopped, they start working again and its normal until they warm up.

I will need to remove the cat and DPF to change the sensor and I'm thinking that you removed these to do your VNT motor?

Looks like probably seized studs that will shear off, did yours come off ok?

foggyjames · Aug 13th, 2021, 10:21

You actually can change the VNT motor without removing the downpipe and/or turbo - just the resonator box (and couplers). The turbo-downpipe nuts were actually fairly easy to move when I tried previously (just go easy, and use plenty of WD40, etc), but the nuts and studs from downpipe to rear section were wasted to the point of barely existing, and both flanges were also badly wasted. After an extended fight (with both a grinder and carbide burr in a drill), they were removed and replaced with set of stainless nuts and bolts. It took forever to get those off without destroying the flanges, though!

cheers

James

Moussey · Aug 13th, 2021, 11:38

Thanks, I was afraid of that.

I have confirmed which sensor it is. Its on top of the pipe. Think I will try and get it out in situ, nothing lost if it breaks. I may then clamp / weld another nut/threaded insert onto the pipe over a new hole. Hey ho.

foggyjames · Apr 3rd, 2023, 12:53

I was just asked about this thread via PM, so I thought I would post an update / conclusion.

Predictably, once I fitted the correct motor / actuator (which was a bit of a nightmare to locate - I ended up buying a complete used turbo to get one), the car drove more or less as it should (albeit intermittently with slightly more lag than I'd expect - I wonder if it needs some sort of mechanical adjustment beyond the software calibration you can do in VIDA).

I didn't note the actuator positions with the new unit. I think by the time I fitted the new item, I'd forgotten about that previous issue.

We never saw the DPF warnings again, so I can only assume that something was temporarily upset by having the wrong actuator fitted.

cheers

James

passenger · Apr 3rd, 2023, 19:49

How so? There is few companies selling Hella original new units.

What did you do with old turbo? I wish I have one, just from curiosity to open it

Aug 10th, 2021, 01:26	#1
foggyjames 300 Register Keeper Last Online: Apr 24th, 2024 09:13 Join Date: Dec 2001 Location: Nottingham	Euro 4 D5 - VNT motor issues, and odd Soot Filter warning Hi All, I've been working on my friend's Euro 4 D5 recently. I told her not to buy a Euro 4 - the runt of the 5-cylinder litter, in my humble opinion, but was I listened to...? She's had it for 3-4 years, and it's been in some level of limp-home state or otherwise misbehaving for most of that time. It has further reinforced my already low opinion of Euro 4s, frankly. I don't get much chance to work on it, but when I do it just seems to be never-ending - fix one problem (or even just see light at the end of the tunnel) and another appears. There's a long story of other things done in the pursuit of making it right (including the swirl flap assembly and arm), but the relevant info is as follows... It was making a noise like it had a boost leak (but I eventually pressure tested as much of the system as I could, and couldn't find anything leaking), and would go 'flat' (like a temporary limp-home) if taken over about 2500rpm at full throttle. If you tried hard enough, you could make it enter limp-home mode properly, with a Engine System Service Required message and a boost control code. Eventually we realised that the VNT motor wasn't moving. My hunch is that the "boost leak" noise is a strange acoustic effect due to the VNT being in the wrong position. This was removed and stripped, and the internal cog was found to be stripped (in the middle, not at either end). The mechanism on the turbo itself appears to be perfectly free, which is odd, especially with the cog wear being in the middle. A friend sold me a motor from a P2 Euro 4 D5, but when we came to fit it, the actuator arm was fitted almost exactly rotated by 180 degrees. This was removed, rotated by 180 degrees, and welded back into position. This motor worked but would only report a range of movement in VIDA of 0.5% to 65% - is that normal, or would something close to 0-100% be expected? With hindsight, I should have investigated further and measured more carefully before rotating the arm, but my memory is that both cog-sets were resting in the middle of their travel, so a 180 degree rotation seemed fair enough. I thought self-calibration (there's an integral position sensor) would take care of any minor inaccuracy. Probably wishful thinking, with hindsight, but not a lot to lose, with the old motor being dead. Further research revealed that there were quite a few different motors fitted to D5s. We're going to get the correct one and try again, naturally, but it would be interesting to know about the range of movement question, as posed above. The new motor moved, but the car was much more limp-homey than before (code ECM-P029900 (Underboost) stored - predictably, if the VNT can't reach the commanded position). It appeared to have a certain amount of go - possibly similar to before. It was certainly driveable if you weren't in a hurry. I assume the VNT was stuck in a mid-position previously, therefore the turbo was able to operate to an extent, albeit with extra lag, and a tendency to overboost and have to be reigned in by the ECU, presumably via fuel cut. It also stored ECM-P004500 (VNT Solenoid open-circuit), although I've slightly lost track of exactly when that appeared. I tried putting the old motor PCB on the new motor, as there is clearly some considerable control electronics inside the motor, and I thought it was possible that the motor could be commanded to run in the opposite direction (given the angle of the actuator arm), or somehow be coded, or talk a subtly different language (in terms of its commands from the ECM) to the earlier motor. The original PCB would move the (new) motor, but only when first plugged in, or when putting the ignition on. It wouldn't move under any other circumstances. Very odd. The complete new motor would seemingly respond normally (aside from the "65% question"). Continuing with the test drive, however...push it too far (not actually far at all...) and it would enter a further stage of limp-home, which left it severely lacking power. Not really usable except at city speeds, or in an emergency for longer runs. I think this "stage 2 limp-home" was triggered by issue 2... Sigh. The second issue appeared on the first drive after fitting the new motor (and no sign of it before, the car mostly living on motorways, etc). "Soot Filter Full" and codes ECM-P245202 (DPF differential pressure sensor general signal failure) and ECM-P242F85 (DPF restriction - ash accumulation - bus signal / message failures - signal above allowable range). The explanation for neither fault is exactly...detailed...! I did a bit of a datalog, and the pressure differential reading was staying stable. The recorded soot level is 22.65g, which VIDA suggest will trigger a "normal" re-gen (and not a limp-home condition!). Pressure at idle was 19hPa (which VIDA says is normal) and maybe 23 when driving (it was pretty much constant). So very slightly high, but I would maybe expect a re-gen, not a fault code and severe limp-home. As far as I can see, neither value should trigger a fault. Sounds more like a spurious reading to me, but nothing was appearing on the datalog (even when the code was triggered). So...DPF experts...what do you think? Could the VNT issue have upset the DPF differential pressure sensor somehow? It will clearly have an effect on exhaust pressure! I am very confident that we didn't disturb the wiring when fitting the VNT motor (which would be an obvious explanation). The timing seems far too much of a coincidence to be entirely unrelated though. The triggering of the DPF codes appears to be load-related. It only really happens when accelerating above say 35mph. Long post, I know. In summary, two questions: 1) What is the normal range of reported VNT motor movement - 0-65%, or 0-100% (ish)? 2) What would cause a seemingly correctly-functioning DPF to trigger a limp-home condition (and the reported codes)? As you can probably tell, this is not my first rodeo, but what I am struggling for here is knowledge of the specific quirks of the Euro 4. I am reasonably confident that the boost codes will go away with new/correct VNT motor, but I am worried about this DPF business...and it's getting to be more than anyone's nerves can take! All thoughts greatly appreciated...! cheers James __________________ VOC 300-series Register Keeper '13 V70 D4 SE Lux '89 740 Turbo Intercooler '88 360 Turbo Intercooler '84 360 GLT '81 343 GLS R-Sport '79 343 DL '70 164 Last edited by foggyjames; Aug 10th, 2021 at 01:31.

Aug 11th, 2021, 18:26	#3
foggyjames 300 Register Keeper Last Online: Apr 24th, 2024 09:13 Join Date: Dec 2001 Location: Nottingham	Many thanks for the info! I agree that it's not 100% conclusive, because VIDA and your scanner might express things differently, but it holds some promise. Have you got any codes stored which might explain your hesitation issue, out of interest? (EDIT: My friend's car is actually a 2.4D, too, but given that the only difference I'm aware of is software, I thought it was easier to just call it a D5. It was mapped at one point, but we had it removed after the clutch started slipping) cheers James __________________ VOC 300-series Register Keeper '13 V70 D4 SE Lux '89 740 Turbo Intercooler '88 360 Turbo Intercooler '84 360 GLT '81 343 GLS R-Sport '79 343 DL '70 164

Aug 11th, 2021, 20:27	#4
cheshired5 Premier Member Last Online: Dec 26th, 2021 13:42 Join Date: Dec 2013 Location: Crewe	I don't know about the turbo issue as I would just fit whatever should be fitted and not get involved in making something else work. My friend's Euro 4 had been having DPF sensor codes and limp mode and I fixed it with a new fuel filter and new glow plugs as they are used for the regeneration process. Fitting a new DPF Pressure Sensor made no difference. I told him it probably wouldn't but he wanted to try as it was cheap and easy to replace. Basically, test all 5 glow plugs and replace the the fuel filter as there's no mention of either above. The Euro 4 is pretty decent but needs absolute basics covering before over thinking problems which I suppose is just like any engine. VNT positions are in Vida in Diagnostics >Vehicle Communication >ECM >Parameters >Description __________________ 2002 S60 SE D5 Manual 209000 miles

Aug 13th, 2021, 10:21	#7
foggyjames 300 Register Keeper Last Online: Apr 24th, 2024 09:13 Join Date: Dec 2001 Location: Nottingham	You actually can change the VNT motor without removing the downpipe and/or turbo - just the resonator box (and couplers). The turbo-downpipe nuts were actually fairly easy to move when I tried previously (just go easy, and use plenty of WD40, etc), but the nuts and studs from downpipe to rear section were wasted to the point of barely existing, and both flanges were also badly wasted. After an extended fight (with both a grinder and carbide burr in a drill), they were removed and replaced with set of stainless nuts and bolts. It took forever to get those off without destroying the flanges, though! cheers James __________________ VOC 300-series Register Keeper '13 V70 D4 SE Lux '89 740 Turbo Intercooler '88 360 Turbo Intercooler '84 360 GLT '81 343 GLS R-Sport '79 343 DL '70 164

Apr 3rd, 2023, 12:53	#9
foggyjames 300 Register Keeper Last Online: Apr 24th, 2024 09:13 Join Date: Dec 2001 Location: Nottingham	I was just asked about this thread via PM, so I thought I would post an update / conclusion. Predictably, once I fitted the correct motor / actuator (which was a bit of a nightmare to locate - I ended up buying a complete used turbo to get one), the car drove more or less as it should (albeit intermittently with slightly more lag than I'd expect - I wonder if it needs some sort of mechanical adjustment beyond the software calibration you can do in VIDA). I didn't note the actuator positions with the new unit. I think by the time I fitted the new item, I'd forgotten about that previous issue. We never saw the DPF warnings again, so I can only assume that something was temporarily upset by having the wrong actuator fitted. cheers James __________________ VOC 300-series Register Keeper '13 V70 D4 SE Lux '89 740 Turbo Intercooler '88 360 Turbo Intercooler '84 360 GLT '81 343 GLS R-Sport '79 343 DL '70 164

Aug 11th, 2021, 09:41	#2
Moussey New Member Last Online: Sep 23rd, 2023 16:33 Join Date: Jan 2013 Location: London	Morning, I have intermittent hesitation/ limp mode issues as well so like to help. Car is a 2009 2.4D I just fired up my car scanner app, not Vida I know but so much easier to use. When idling "Turbo bypass or VNT" runs at 95%. When pulling against the brakes with boost unto 100 odd kpa it goes to 100%. If you blip it then on the overrun it goes down to 30% ish. When the engine is killed it drops back to 0% after about 5-8 seconds and makes a noise like a muntjac barking if you know what that's like. I'd always wondered what the noise was so am really chuffed to have found out. Hope that helps, I do appreciate that my generic scanner %s may not map to Vida but given the ranges it seems they do should. The car is on ramps at the moment and I will be road testing to see if I can pin point the hesitation.

Aug 13th, 2021, 08:35	#6
Moussey New Member Last Online: Sep 23rd, 2023 16:33 Join Date: Jan 2013 Location: London	Happy to have hopefully helped. I only have the PO428 DTC but I drove it yesterday. The cat #2 temp sensor and the DPF temp sensor ( Think they are the same thing) breaks down when it gets warm and the car goes into limp mode. If driven slowly, or stopped, they start working again and its normal until they warm up. I will need to remove the cat and DPF to change the sensor and I'm thinking that you removed these to do your VNT motor? Looks like probably seized studs that will shear off, did yours come off ok?

Aug 13th, 2021, 11:38	#8
Moussey New Member Last Online: Sep 23rd, 2023 16:33 Join Date: Jan 2013 Location: London	Thanks, I was afraid of that. I have confirmed which sensor it is. Its on top of the pipe. Think I will try and get it out in situ, nothing lost if it breaks. I may then clamp / weld another nut/threaded insert onto the pipe over a new hole. Hey ho.

Apr 3rd, 2023, 19:49	#10
passenger Master Member Last Online: Apr 2nd, 2024 21:40 Join Date: Feb 2021 Location: Mountains	How so? There is few companies selling Hella original new units. What did you do with old turbo? I wish I have one, just from curiosity to open it

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