EGR Bypass constant reading of 100%. Poor acceleration

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ImNoExpert
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EGR Bypass constant reading of 100%. Poor acceleration

Post by ImNoExpert »

Hi folks. I'm by no means a Pro at all but got enough knowledge to at least know there is a problem with my van.

2105 2.0 hdi 130 L2H2 176k miles. Full Service. Ex Euro Car Parts van. 6k in receipts including new Clutch last week and Turbo less than 10k ago and EGR in 2020 or 14k miles ago.

Erratic rythmic idle but the needle is steady RRrrrRRrrrRRrrrRRrrrRRrrr. Intermittent jerking and stuttering at low revs or pedal position. Boost is fine in lowers gears or lower speeds but loses it later on. 0-60 takes 20 seconds or more. No Smoke (sometimes at startup it's chuffing white smoke that doesn't appear to be un-burnt diesel but can't confirm-could it be coolant from EGR?) No Engine Light and No Codes showing on my el cheapo VGATE ELM327 scanner. I'm using the FAP software from Amazon. So far I've checked for vac leaks, but I've got a vacuum testing kit coming tomorrow and booked in for a full Live data Diag on Tuesday next week. I've been trying to figure this out for 3 months. It Starts Runs and Drives. I bought it like this from the dealer who refuses to acknowledge there is a problem. The dealer is 2hrs or 110 miles away from me, However he did recover it and replace the slipping clutch. It also had an injector leaking which he fixed but must have been like that for some time as the entire top of the injector seating area is covered in a brown carbon/tar covering.

I've recently changed the Air and Fuel filter, brand new MAP and MAF. Air Dozer is clean like new and in the receipts the Inlet manifold was stripped and cleaned about 10k ago (but long enough to clog again I guess).

However, before we start down a Rabbit Hole, let's start from what I can immediately observe using OBD2 and the FAP app. I'll add the readings in the next post.


DPF 90% Cinder (it Regens fine but the left over cinder count is 90%-numbers suggest 17k miles before DPF 100% blocked). a quick Diagnostic 3 months ago showed massive backpressure, but it wasn't confirmed.
EGRBypassInstruction 0% EGRBypass Position 100% (In Red) constant. While the EGR Instruction request changes as I drive, the EGR position shows at 100% for the entirety, either at Idle or while travelling.
The EGR vacuum pushrod can be moved by hand but does feel a little gritty in operation, however it appears to have full travel and does show vacuum at cold start which releases to default position when warm. Readings from OBD2 don't change. I don't know what the default position is; Open or Closed? What does Open or Closed represent? What is Default Position?


I hope you can help me out and hope I can help out too.

Nice to meet you all.
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GiveMeABreak
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Re: EGR Bypass constant reading of 100%. Poor acceleration

Post by GiveMeABreak »

My first thoughts are that being en ex-Euro Car Parts van, they've probably used their own parts :roll:

Puns aside, it probably needs a diagnostic with Diagbox and not one of those FAP kits as they likely can't read the specific constructor codes. Many of these generic OBDII readers are only good for basic fault finding.

Regarding the vehicle - it's done 176K miles and I suspect the DPF is becoming blocked. Regeneration only burns of the particulate matter and soot, but the Eolys additive contains Cerine that can't be burned off during regeneration. This, over time, along with engine debris and other deposits is what ultimately blocks the DPF. They only have a finite life before they need replacing or deep cleaning. If your vehicle is on the original DPF then it is way past it's service life and will be unable to do its job.

There are several readings, one shows the current status of the filter, which rise and fall. When a regeneration cycle has completed the levels fall back to near zero. Then the cycle repeats, so depending on when you undertake a diagnostic the reading will show a different level.

There should be another reading that shows the quantity (weight in grammes) of Cerine from the additive that has been dumped into the particulate filter since new. When this gets to a specific level, calculated by the engine ECU, it deems the filter is end of life and needs replacing. Normally you would be getting 'Risk of particle clogging' messages coming up, or the engine management light / service lights.

So if the filter is blocked that may also contribute to the lack of power, stuttering etc. Of course once you have a thorough diagnostic, pop the codes up here with the VIN as without those you're pretty much going to be guessing and it could be anything.
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Re: EGR Bypass constant reading of 100%. Poor acceleration

Post by ImNoExpert »

Thanks for your reply, Marc....I forgot to add the FAP readings and also mention that I've had tit on my neighbours 1.6hdi of same year and his readings are all 0% in green, where my EGRbypass Pos is 100% Red constant.
I'll post a full screen image soon.
Image
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Re: EGR Bypass constant reading of 100%. Poor acceleration

Post by ImNoExpert »

Sorry folks I meant to add this info in the initial post. It has just completed a Regen in the last day or so.
FAP.jpg
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GiveMeABreak
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Re: EGR Bypass constant reading of 100%. Poor acceleration

Post by GiveMeABreak »

Ok, so I think we can ignore the DPF as that looks OK to me.

Now I don't normally pop fault codes up without this having being confirmed, but from the sorts of things you are talking about, if you look at the symptoms below, this would seem to suggest some common symptoms with what you have described.

My first thoughts would be the EGR - and if it was an aftermarket one (ECP?) as they have a bad reputation for non-branded parts. Although I can't see a 'learning' procedure for replacement of the EGFR, that doesn't mean that there isn't something in the diagnostic menu to inform the Engine ECU that it has been changed, which may trigger a re-learning, which is indicated in the possible causes section below. But if the bypass is stuck on 100% then it's obviously not operating correctly....
Fault Code: P14A7
Description of Fault: EGR valve: Failure of the first initialisation. Failure of the initialisations of the stops of the EGR valve. The fault occurs during the sleep phase of the engine ECU
Conditions for Fault to clear: Request for first initialisation to be redone due to actual or supposed replacement of the EGR valve
Downgrade Modes whilst Fault is active:None
Symptoms:
  • Engine hesitating, cutting out
  • Malfunctioning of the idle
  • Lack of power
  • Starting problem
  • Noise
  • Diesel fuel consumption a bit higher
  • Smoke from the exhaust
Suspect Areas:
  • Electrical harness
  • Connectors
  • Exhaust gas recycling valve
  • Failure of the first initialisation of the stops of the EGR valve
  • Malfunctioning of the EGR valve position copy
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Re: EGR Bypass constant reading of 100%. Poor acceleration

Post by RichardW »

That doesn't look like EGR to me - the EGR request / position is given as 46% matching. Not sure the config on this engine, it says air mixer which is (probably) the doser valve on the intercooler and matching request / position, but not sure if there is another valve somewhere or if this is bum info from the scanner!
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Re: EGR Bypass constant reading of 100%. Poor acceleration

Post by GiveMeABreak »

I think this will be the DW10CD engine and my thoughts are that this is a combined module Richard and can't be separated, so the cooler is integral to the module and given the dodgy always open reading, that's where my thoughts lie.
EGR Cooler.PNG
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Re: EGR Bypass constant reading of 100%. Poor acceleration

Post by ImNoExpert »

Yes, Marc that is the part on my van. Water cooled.

As Marc has said, Richard, the Cooler is part of the unit and the Valve in question switches gas to either Cooler side to be used for turbo, to Warm side to be used for Cold start etc. and is to be used freely through the driving cycle to regulate cooled airflow to turbo. you are reading the EGR values which seems correct, but the EGR Cooler Bypass is in question here. It may or may not contribute to my symptoms.

What I don't know is what the default position is. Does it start Open or Closed? What does Open or closed represent? I am going to assume that as the readings from the Scanner show 0% while running but increases when accelerating that this means the Cooler is in Operation to supply the Turbo with cooled Air. So the request from ECU to EGR Cooler valve might be working but the response is stuck at 100% but no Engine light....and it's been like this for 1500 miles!

I ask the default position as the vacuum shaft rod is extended when engine off or warm, but on a cold start it actuates to either an open or closed position. either way when it is warm the vacuum is relaxed. For this reason I believe the valve itself may be working, so it could be a sensor within the unit or ECU fault as the 100% value never changes.
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Re: EGR Bypass constant reading of 100%. Poor acceleration

Post by ImNoExpert »

An interesting point to mention, folks.

this van that is ex-Euro CP fleet is fitted with a Soft Speed Limiter that degrades output from 60mph to 70mph. I have always considered that this Speed Limiter also reduced power output.

Is it possible that the ECU Map on these vans may restrict power output as well as Top Speed? Could the ECU be limiting turbo in higher gears as part of the restriction? Could the fact it's showing 100% constant be part of the Mapping out of the fault? Just a thought from a novice. :D
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Re: EGR Bypass constant reading of 100%. Poor acceleration

Post by GiveMeABreak »

Interestingly, on the DW10CTED4 engine fitted with this module, programming is required if fitted or replaced.....

This gives a little more info on the unit that may or may not be of use concerning it's operation and the stages:
EGR Cooler A.PNG
1) Electrically-controlled exhaust gas recycling valve (With integral position copy sensor).
(2) Exhaust gas recirculation heat exchanger.
"a" 3-way blue connector (Position copy sensor for the EGR heat exchanger by-pass flap).
"b" 5-way blue connector (Electrically-controlled exhaust gas recycling valve).
"c" Control capsule (By-pass flap with integral position copy sensor).
"d" Exhaust gas outlet.
"e" Water entry.
EGR Cooler B.PNG
(1) Electrically-controlled exhaust gas recycling valve (With integral position copy sensor).
"f" Coolant outlet.
"g" Exhaust gas inlet.
Make: VALEO.

Role

Role: Exhaust gas recycling valve (EGR) (With integral position copy sensor):
  • Allowing the intake of a specific quantity of recycled exhaust gas into the air supply circuit
  • Cooling or otherwise of the recycled exhaust gases
Function

Exhaust gas recycling valve closed
EGR Cooler C.PNG
(2) Exhaust gas recirculation heat exchanger .
(3) Body : Exhaust gas recycling valve (EGR).
"d" Exhaust gas outlet.
"g" Exhaust gas inlet.
"h" Valve : Exhaust gas recycling valve (EGR).
"j" Gear wheels.
"k" engine.
"l" By-pass flap/Exhaust gas recirculation heat exchanger .
Exhaust gas recycling valve closed: No recirculation of the exhaust gas.


Exhaust gas recycling valve open - By-pass flap/EGR heat exchanger closed (By-pass position)
EGR Cooler D.PNG
(2) Exhaust gas recirculation heat exchanger.
(3) Body : Exhaust gas recycling valve.
"d" Exhaust gas outlet.
"g" Exhaust gas inlet.
"h" Valve : Exhaust gas recycling valve.
"j" Gear wheels.
"k" engine.
"l" By-pass flap/Exhaust gas recirculation heat exchanger .
The motor of the EGR valve is controlled by an open cycle ratio (OCR) signal: Opening of the EGR valve is proportional.
Exhaust gas recycling valve open : Exhaust gas recycling.

By-pass flap/EGR heat exchanger closed:
  • The recycled exhaust gases do not pass through the exchanger
  • The recycled exhaust gases pass are not cooled
The EGR heat exchanger/by-pass flap has only two positions (Open - Closed).


Exhaust gas recycling valve open- By-pass flap/EGR heat exchanger open (Exchanger position)
EGR Cooler E.PNG
(2) Exchanger.
(3) Body : Exhaust gas recycling valve.
"d" Exhaust gas outlet.
"g" Exhaust gas inlet.
"h" Valve : Exhaust gas recycling valve.
"j" Gear wheels.
"k" engine.
"l" By-pass flap/Exhaust gas recirculation heat exchanger .
Exhaust gas recycling valve open : Exhaust gas recycling.

EGR heat exchanger open:
  • The recycled exhaust gases pass through the EGR heat exchanger
  • The recycled exhaust gases are cooled
DesignationMinimum toleranceNominal valueMaximum tolerance
Electric motor supply voltage10,5V13,5V16V
Resistance of the motor at a temperature of 20°C2,25 ohms2,5 ohms2,75 ohms
Supply voltage of the EGR valve sensor4,75V5V5,25V
Range for signal in closed position, of the EGR valve position copy sensor0,672V0,7V0,728V
Range for signal in open position, of the EGR valve position copy sensor4,224V4,4V4,576V
Supply voltage of the by-pass sensor/Exhaust gas recirculation heat exchanger4,75V5V5,25V
Range for signal in exchanger position, of the by-pass sensor/Exhaust gas recirculation heat exchangermore than 0,5 V-less than 1,5 V
Range for signal in by-pass position, of the by-pass sensor/Exhaust gas recirculation heat exchangermore than 3,5 V-less than 4,5 V

Signal from the EGR valve position copy sensor
EGR Cooler F.PNG
"A" Diagnosis zone .
"B" valve open.
"C" Valve closed.
"U" Voltage ofthe signal in volts.
"P" Position of the valve (%).

Control signal of the EGR valve
EGR Cooler G.PNG
"P" Position of the valve (%).
"R" RCO control (%).
N.B. : OCR = Open Cycle Ratio.


Signal from the by-pass flap position copy sensor/Exhaust gas recirculation heat exchanger
EGR Cooler H.PNG
"A" Diagnosis zone .
"D" By-pass mode.
"E" Exchanger mode.
"U" Voltage ofthe signal in volts.
"P" Position of the valve (%).
ImNoExpert
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Re: EGR Bypass constant reading of 100%. Poor acceleration

Post by ImNoExpert »

Firstly let me just say..wow and Thank you.....where do I get access to this kind of info????

However the unit is a Valeo brand but differed to this as it does not have the extra sensor a blue 3 way.

I believe my engine is DW10CD PEF 94KW DTR 1997 DIES.

It appears that EGr may be from a Euro 6? where mine is a Euro 5. The flap is Vacuum activated. This one appears to be Electronically actived.
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IMG20220804141256.jpg
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Re: EGR Bypass constant reading of 100%. Poor acceleration

Post by ImNoExpert »

Before we get too far into what might be 'wrong' with the van. can anyone confirm the 0-60 expected? 20 seconds or more doesn't seems right. I have read on various documents it should be around 13 seconds.

I used to own a 2007 Scudo of same shape. It went like a rocket. Is it possible that this can is just slow? Maybe something changed or specific to this model. It is a 130bhp.
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Re: EGR Bypass constant reading of 100%. Poor acceleration

Post by ImNoExpert »

I wonder if you can tell me what is reading the 100% position? Is it the Cooler sensor on the EGR or the ECU or something else? I read somewhere that the ECU is sending the request, but as it is vacuum operated it knows nothing of what actually happens at the other end and simply assumes the request has been received. But then i would suggest issues with O2 readings coming out and all kinds of engine light codes popping up? Am i thinking too much or not enough? :D
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Re: EGR Bypass constant reading of 100%. Poor acceleration

Post by ImNoExpert »

I'm starting to think now that the 100% in red is a default value as there is no feedback loop? If what I mentioned earlier is true about the ECU sending but not knowing what values are present as there is no feedback sensor attached, then is this why it's 100%? I could be looking in the wrong place for answers. It might simply be worn injectors after all?

However, I'd still like to confirm the 0-60 speed as the dealer is adamant that he has several of these and sold several of these and mine runs as good or the same as the others. However, this is the same dealer that didn't know the injector seal was leaking, the clutch was slipping, the exhaust was resting on the rear axle and the drop link was knackered and the cabin heater blower wasn't' connected to the ducting, or the spare wheel was missing........
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Re: EGR Bypass constant reading of 100%. Poor acceleration

Post by ImNoExpert »

OK, morning people.

I have another theory. While reading another post on here viewtopic.php?t=58705&start=15 Member 'xf1ref' suggested the Air doser be linked to the ESP Traction Control/Anti Skid. In the event of a skid the power is limited by use of the EGR/AirDoser/Throttle body.

Coincidentally, I have had several warnings of an ABS/Brake Fault on the display in the van......but still No Engine Light and no codes from my vgate EML scanner. I have an ESP button on my centre console that illuminates if I press it On/Off, but there's no indicator for it in the Instrument Cluster!

So, might a fault be there witht e ESP/ABS/Speed Ring that has not thrown a code, but IS limiting my throttle as a response?

My head is going to explode. Can't wait till Tuesday for Live Diag but what if it doesn't show anything?


I still need my 0-60 confirmed guys and gals. :D