[Derekh]

Hi I'm new here so please bear with me. I could do with some help from someone who has a good working knowledge of how the 1.9 cdti egr valve and monitoring system works.

My daughter bought the above vehicle, basically a Vectra C 1.9 cdti with a modified rear end. She bought it knowing it had the CEL/MIL light on and being informed this was because the vendor had blanked the EGR valve but had not had it deleted in the ECU, which made sense. After buying it we found it was blowing black smoke on acceleration.
Eventually found the swirl bar was off so bought a remanufactured one, which stayed on and worked! But the car still blew black smoke and had the MIL light on although to be fair the performance was good.
Eventually after researching we decided on a swirl flap delete kit which was fitted and the manifold and EGR valve fully cleaned up along with the MAP?boost sensor, the throttle body had been cleaned out and drained a few weeks prior to this. Removing the manifold on these engines is a nightmare but we got it done eventually. No more black smoke....success!! But the b****y MIL light still comes on even after the codes have been cleared. OBD scanner shows a P0400 code.
We took the car for a Tech2 check at an independent garage, free I might add, which they said was showing p0401 insufficient flow. They said the EGR would be the problem.
Had an auto electrician test the EGR with a special scanner tool which showed the valve was sticking a tiny amount and again advised change the EGR valve.
Bit the bullet and invested in a genuine Peirberg EGR valve and cleared the p0400 error. Came back after a few minutes running! The car though runs just fine now!! Have since replaced the MAP sensor with a genuine Bosch item again the code came straight back after clearing the codes. Replaced the MAF with a known good one and again the code came back a few minutes after having been cleared.
I hate EGR valves! Nothing but problems!
Decided to check the wiring and found that the two connectors inside the plug where reading voltages but can see that the valve has been opening as it should by the small amount of carbon on both sides of the circular valve plates.
Anyway after researching some more set about checking the EGR cooler and feeder pipes to see if they were blocked. The cooler was a little sooty but not at all blocked, to be doubly sure used a steel cable to feed down the cooler bores and then washed out with petrol. Refitted the whole lot and guess what another 4 hours wasted!! Yes still have the dread p0400 code.
The only code the car has been showing now for the last month or more is the dreaded P0400, nothing else is recorded.
Almost at my the end of my tether with this now.
Only things I can think of now after researching a lot more are a small chance of the exhaust being blocked because of a damaged DPF. Doubt this is the case as the car flies now and I don't think they fitted the 2004 Signum with a DPF anyway.
Or that it could be that the wiring loom to the EGR is below par somewhere, but where to look, beyond the first foot or so and it just all disappears into the main engine loom.
Last option is that there is a problem with the ECU.
My daughter has been advised to change the lambda sensor but I'm loath to do that as their is no indication this is faulty.
Really hoping to find someone here who can give some expert advise on were to go from here. Don't want to go to Vauxhall as they will want a fortune and will insist on changing all the stuff already done at our expense and still end up in the same boat as now.

[Hometune]

I am assuming your engine code is Z19DTH.

The fault code is P0401 obtained from Tech 2. Diesel engine cars only had to be OBD compliant from 2004 so you are getting an incomplete code from the OBD scanner if it is P0400. Tech 2 is giving a description along with the code so best rely on that.

Insufficient flow is almost always caused by soot/carbon build up. I know you have cleaned out the manifold/flaps/EGR valve etc. but.......

The large air inlet pipe is above the gearbox and runs into the air flap (some call it the throttle flap). Remove the pipe then remove the air flap housing (3 torx bolts). Now remove the EGR valve completely. As you look into the inlet manifold there are 2 concentric rings in the casting. They may not be visible if sooted up badly, often being mistaken for a rubber O ring or a gasket. It isn't.
So push a piece of wire through from the EGR housing into the space between the rings and ensure you can see through clearly. This ring must be free of carbon/soot. This is where flow from the EGR is fed into the inlet manifold. If this is properly clean and also the convoluted stainless pipe, all the way through, to the EGR then you need to do some checks using Tech 2, not the OBD tool which is virtually worthless on this car.

You can operate the EGR valve remotely using the diagnostic tool. This will prove if it actually works and travels fully. In the "actuator menu" the valve can be operated with the engine running and you will hear the engine note change as the valve is opened and closed. It can also be operated after removal but still connected to the wiring plug. Was the Pierburg valve from a Vauxhall dealer or Euro Car Parts?
If the valve can be actuated correctly you need to see what it is doing with the engine running on a hot engine. In the "live data" menu you will find the EGR position 'set value' (this is what the ECU is commanding) and the EGR solenoid valve 'actual position'. These MUST be almost identical at all times.
(Note that after 3 minutes of idling the EGR system is disabled so give a burst of throttle to keep it 'alive')

Assuming the valve is within limits now check the airflow through the MAF in the "live data" on the tool. Again the reading must be the same for the 'Air Mass nominal' and the 'Air Mass taken in'.
If the reading is too high then possibly the EGR is too far open. If too low then suspect an exhaust blockage such as a DPF partially blocked. This can be checked for soot quantity on the tool - if fitted. If necessary carry out a forced regeneration. Another possibility for low MAF is a sooted up turbo where the vanes are not moving properly. This can be cleaned with some success by using a cleaner such as Revive (a search will find suppliers). If the DPF is loaded with soot then also ensure the small pipe to the pressure sensor is clear and is not damaged as they split with excess pressure.

Any of the above can cause P0401.

If you have the DPF (if fitted - large tube halfway along the exhaust and looks like a silencer with one small pipe or possibly two coming from it)) and the EGR removed along with a proper reprogram of the ECU then all these problems will go. Costs around £300.

[Derekh]

Hi Hometune and thanks for your speedy reply.

We have been relying on the Tech2 p401 code rather than the p400 code off the cheap scanner as I understand these only give generic type error codes.
The cleaning thing is what I tried 1st off, easiest and cheapest but didn't work I'm affraid. I found the concentric rings you describe and they were badly choked up with a thick sticky black treacle and sorted this after trying the EGR valve cleaning routine.
One thing I forgot to mention is that the blanking plate that came with vehicle was removed early on to try and clear the error code and is still off. May consider fitting a Fiat type restrictor plate once and if it get sorted eventually.
Whilst the manifold was off for the swirl flap delete it was cleaned really well with oven cleaner several times and went back on squeaky clean. Recently I have run a flexible bottle brush through the convoluted pipe to the EGR and also the one into the EGR cooler. Not much came out of these really. The EGR cooler saw also removed and checked for blockages and cleaned out with a brake cable and then petrol for good measure.
I can see us having to pay the auto electrician another visit to run his Tech2 on the car for live data.
I don't think the car has a DPF to be blocked as it was manufactured in Nov/Dec 2004 and the performance is still what I would call good. The car will be over here tomorrow so will check underneath for signs of a DPF then.
You mention the turbo vanes could be sooted up, is it possible to visually check this on these cars relative easily? Is REVIVE similar to a product called CATACLEAN which I have heard of before for about the same sort of money but think that has to been done by aq professional garage.
On the subject of the turbo on this car it does whistle some what, not very loud but there! I have read that most 1.9 cdti's of any real age all have some whistle and that it's nothing major to be worried about could this indicate sooting on the vanes?
We had toyed with having the EGR deleted from the ECU but I was sure it would sovle this issue if was something unusual causing the CEL/error code.
Are there any other sensors that could bring up this code besides the MAP and the MAF? Would an EGR wiring fault/bad connection show up on the live data using Tech2 if they were bad?

[Derekh]

Hi Hometune and thanks for your speedy reply.

We have been relying on the Tech2 p401 code rather than the p400 code off the cheap scanner as I understand these only give generic type error codes.
The cleaning thing is what I tried 1st off, easiest and cheapest but didn't work I'm affraid. I found the concentric rings you describe and they were badly choked up with a thick sticky black treacle and sorted this after trying the EGR valve cleaning routine.
One thing I forgot to mention is that the blanking plate that came with vehicle was removed early on to try and clear the error code and is still off. May consider fitting a Fiat type restrictor plate once and if it get sorted eventually.
Whilst the manifold was off for the swirl flap delete it was cleaned really well with oven cleaner several times and went back on squeaky clean. Recently I have run a flexible bottle brush through the convoluted pipe to the EGR and also the one into the EGR cooler. Not much came out of these really. The EGR cooler saw also removed and checked for blockages and cleaned out with a brake cable and then petrol for good measure.
I can see us having to pay the auto electrician another visit to run his Tech2 on the car for live data.
I don't think the car has a DPF to be blocked as it was manufactured in Nov/Dec 2004 and the performance is still what I would call good. The car will be over here tomorrow so will check underneath for signs of a DPF then.
You mention the turbo vanes could be sooted up, is it possible to visually check this on these cars relative easily? Is REVIVE similar to a product called CATACLEAN which I have heard of before for about the same sort of money but think that has to been done by aq professional garage.
On the subject of the turbo on this car it does whistle some what, not very loud but there! I have read that most 1.9 cdti's of any real age all have some whistle and that it's nothing major to be worried about could this indicate sooting on the vanes?
We had toyed with having the EGR deleted from the ECU but I wasn't sure it would solve this issue if there was something unusual causing the CEL/error code.
Are there any other sensors that could bring up this code besides the MAP and the MAF?
Would an EGR wiring fault/bad connection show up on the live data using Tech2 if they were bad?

[Derekh]

Hi Hometune and thanks for your speedy reply.

We have been relying on the Tech2 p401 code rather than the p400 code off the cheap scanner as I understand these only give generic type error codes.
The cleaning thing is what I tried 1st off, easiest and cheapest but didn't work I'm affraid. I found the concentric rings you describe and they were badly choked up with a thick sticky black treacle and sorted this after trying the EGR valve cleaning routine.
One thing I forgot to mention is that the blanking plate that came with vehicle was removed early on to try and clear the error code and is still off. May consider fitting a Fiat type restrictor plate once and if it get sorted eventually.
Whilst the manifold was off for the swirl flap delete it was cleaned really well with oven cleaner several times and went back on squeaky clean. Recently I have run a flexible bottle brush through the convoluted pipe to the EGR and also the one into the EGR cooler. Not much came out of these really. The EGR cooler saw also removed and checked for blockages and cleaned out with a brake cable and then petrol for good measure.
I can see us having to pay the auto electrician another visit to run his Tech2 on the car for live data.
I don't think the car has a DPF to be blocked as it was manufactured in Nov/Dec 2004 and the performance is still what I would call good. The car will be over here tomorrow so will check underneath for signs of a DPF then.
You mention the turbo vanes could be sooted up, is it possible to visually check this on these cars relative easily? Is REVIVE similar to a product called CATACLEAN which I have heard of before for about the same sort of money but think that has to been done by aq professional garage.
On the subject of the turbo on this car it does whistle some what, not very loud but there! I have read that most 1.9 cdti's of any real age all have some whistle and that it's nothing major to be worried about could this indicate sooting on the vanes?
We had toyed with having the EGR deleted from the ECU but I was sure it would sovle this issue if was something unusual causing the CEL/error code.
Are there any other sensors that could bring up this code besides the MAP and the MAF? Would an EGR wiring fault/bad connection show up on the live data using Tech2 if they were bad?

[Hometune]

The P0401 is not caused by the MAF or MAP sensors so you can rule them out. It is a lack of exhaust gas flow from the exhaust via the EGR valve back into the inlet manifold.
1. clear the code with your scanner, ignition on, engine off.
2. remove the scanner. reconnect the scanner. Switch the ignition on.
3. does the fault code return (wait a minute or two and read the fault codes again) without the engine running?
4. if it does then either the EGR has failed or the wiring to it or the ECU itself.
5. if it does not then start the engine. Do not touch the accelerator pedal. Check for codes. Does it come on now?
6. If it does not then give a burst of pedal up to around 3,000 rpm. Does it come on only after you rev it up?

Is the EGR valve a genuine Vauxhall part? Yes/No?
After removing the inlet manifold swirl flaps did you have the ECU reprogrammed?
Cataclean is for catalysts. Revive is for inlet manifolds and turbos. (Google Revive)

Best to have the car back on Tech 2 to see the readings expected in my previous post. I suspect the ECU is not programmed to know the swirl flaps have been removed presumably along with the actuator? So, at idle and revs up to around 2,500 rpm the engine is able to take in excess air which it could not otherwise do. This means the fuelling is wrong if it has not been remapped. It also affects the exhaust gases and may well be the reason why the EGR flow is insufficient. With the swirl flaps closed a predetermined amount of gas is recirculated, controlled by the EGR and the MAF.

I think that if you have removed the flaps then you may as well remove/blank the EGR, remove the DPF if fitted and have the ECU properly reprogrammed.

[Derekh]

Originally Posted by Hometune

The P0401 is not caused by the MAF or MAP sensors so you can rule them out. It is a lack of exhaust gas flow from the exhaust via the EGR valve back into the inlet manifold.
1. clear the code with your scanner, ignition on, engine off.
2. remove the scanner. reconnect the scanner. Switch the ignition on.
3. does the fault code return (wait a minute or two and read the fault codes again) without the engine running?
4. if it does then either the EGR has failed or the wiring to it or the ECU itself.
5. if it does not then start the engine. Do not touch the accelerator pedal. Check for codes. Does it come on now?
6. If it does not then give a burst of pedal up to around 3,000 rpm. Does it come on only after you rev it up?

Is the EGR valve a genuine Vauxhall part? Yes/No?
After removing the inlet manifold swirl flaps did you have the ECU reprogrammed?
Cataclean is for catalysts. Revive is for inlet manifolds and turbos. (Google Revive)

Best to have the car back on Tech 2 to see the readings expected in my previous post. I suspect the ECU is not programmed to know the swirl flaps have been removed presumably along with the actuator? So, at idle and revs up to around 2,500 rpm the engine is able to take in excess air which it could not otherwise do. This means the fuelling is wrong if it has not been remapped. It also affects the exhaust gases and may well be the reason why the EGR flow is insufficient. With the swirl flaps closed a predetermined amount of gas is recirculated, controlled by the EGR and the MAF.

I think that if you have removed the flaps then you may as well remove/blank the EGR, remove the DPF if fitted and have the ECU properly reprogrammed.

Not entirely sure how this forum works at present, hence the duplicated replies I made above.
Thanks for all the trouble shooting tips with the error code Hometune will be trying some of this tomorrow hopefully if the scanner comes back with the car that is.
The valve is not genuine Vauxhall but a genuine Pierberg we bought from Euro a few weeks ago. The swirl flap actuator motor is still in situ and electrically working though obviously not mechanically connected now, so the ECU still see's the actuator and operates as it should, this is as per the How To on I found on the Vectra C forum. Removing the actuator apparently definately brings on the CEL light so this is why it is left insitu and plugged in. The author doesn't mention any need for the ECU to be reprogrammed at all.
Do you have any idea of where the ECU is located on the Vectra C Hometune?

[Hometune]

I would never ever, ever buy an EGR valve from Euro. I was called by a dealer to a C4 3 times and each time told him it was the EGR valve. After fitting 3 brand new ones, he didn't believe me so he took it to a specialist Citroen garage who confirmed it was the valve. So in total he fitted 3 EGR valves supplied by Euro and not one worked. Fitting one from Citroen and the car was sorted. It may say Pierburg on it but it is likely to be reconditioned from China. Just my experience.

I don't understand how the air flaps cannot be causing you problems. The actuator is being commanded by the ECU as the revs increase so the ECU thinks the flaps are opening. As they are open all the time I am surprised you do not get a P2279 fault code - air leak - and this must have a bearing on the operation of the intake and exhaust system. I have not come across this removal but on every Z19DTH I've done with a broken air flap system, replacing the inlet manifold with a proper one, a new actuator, a genuine EGR and the cleaning you have done has resulted in the cars being fixed. Even those later ones with a DPF have been sorted. I'm not sure of the benefit of the air flap removal.

ECU should be behind the driver's side wheel arch cover.

[Derekh]

Ok Hometune I can see where your coming from with the EGR valve probably being reconditioned but I wasn't sold a recon unit. I've checked the boxing and it has the Pierberg logo all over it and a security seal, which I had to break, bearing an address in Germany, MS-Sport or the like and much more business like than the previous HAAS EGR they sold us.
Daughter has been over this afternoon and we, her young man and I that is, had another look at things and started running through your trouble shooting hints. Made some progress and we found that after clearing the fault as you said that it would not show up with the ignition on only but would show up within a few seconds of starting the engine.
We were about to try and use a voltmeter to check what voltages were on the two terminals in the electrical connector, when her young man decided to spray the plug/contacts with Plusgas, while I was getting the meter. WELL we now have a happy Signum! No CEL and no pending errors either after running the car for a good 15 mins and a short test drive. So fingers crossed this stays away for a few days at least and confirms an problem with the plug itself.
Can't believe that something so silly could have caused all this, that connector must have been on and off over the last few months over twenty times attempting a cure. No idea how long the Plusgas will effect a cure and expect it will most like mean splicing a replacement plug and wires onto the original loom.
Thanks again for your time and input Hometune.

[Hometune]

Glad you have sorted it. Might be worth using a small screwdriver to gently push the pins in the EGR valve very slightly apart and this will make the contact in the plug much better.

[Derekh]

Back again hometune!

Thought this was all sorted but alas it's not.

Car was fine for close on a week no error codes spanner or CEL lights of the dash. I decided that the as the P0400 code went away when the plug was sprayed with plus gas that the plug itself was the culprit so got hold of a good plug with a good length of wires from the local breakers. I cut away the old plug jioned the old to the new wires and soldered everything back up. My soldering skills are good, I spent the 1st 10yrs of my working life as a telephone engineer and soldering was a must there.

Anyway it all seemed to go well no codes or lights until after I handed the car back to my daughter saying it fine now! She straight back OH NO its not. CEL back on and the same old P400. I was most unpopular for a short while.

Well today I've had look at the thing checked my soldering and it all good, thought there must be a wiring fault in the loom near to the egr so checked continuity back to the main loom and that was fine. Tried clearing the codes but spanner light back on and then the CEL. Exasperated or what. I cleared the codes once more then had to move the car a short distance and then noticed the the lights HADN'T come back on. Thought I must have disturbed the wiring fault but on checking found I had left the EGR unplugged. Back to the scanner and rescanned but no codes!

Well took the car out for a good drive, about 4 or five miles and there still aren't any codes stored which is very nice! I can't understand for the life of me why the ECU is not complaining about the egr not being connected. Infact I now think this is what happened when the plug was sprayed with plusgas and put back on, in that the was faulty and wouldn't connect after it was sprayed. Should the ECU be happy with an unplugged valve? My understanding is that it should monitor the the voltages on the two wires and flag up an error if it doesn't see voltages within a specific range. With it disconnected there can't be any feedback. Wondering now if there is a problem with the ECU? Any thoughts Hometune

[Hometune]

The ECU will monitor the position of the EGR valve so it should put the light on. Before condemning the ECU, I would drive to the nearest scrapyard and borrow an EGR valve. No need to fit, just connect it electrically and see if the light comes on. If you had a scanner that could move the valve then you would know for sure.

[Derekh]

Will try another EGR valve, we have a spare one that was cleaned but was still giving the P0400 error hence buying the new Pierberg. We did try this valve, as you've suggested, immediately before the the Plusgas was used and I noticed that when the engine was started the valve wasn't pulsing at all.
Fairly sure the scanner we have can't operate the EGR.
Think the fact that the ECU isn't complaining about the valve being disconnected is going to mean there is a problem there of some sort. Might not bother to much if we can't solve this as it seems as though it acting almost like having the EGR mapped out.
Have read somewhere about similar issues to this which was eventually proven to be a bent connector in the ECU plug. Won't be able to get my hands on the car until this Sunday now and think it may be a bumper off job to get into the ECU properly.

[Hometune]

With the flap mod done and if the car doesn't smoke and there are no issues, leave it unplugged. This is just the same as blanking it off. Think you've tortured yourself enough!