Fabia Suddenly Stops, ECU Fuse Replaced, Now Won't Stop At All!

[TMB]

...but long may yours continue to remain undamaged, just keep an eye on it anyway!

 

Neil

 

Thanks, I will :)

[rum4mo]

I have wondered why the recalls that have happened were so specific in their date ranges, as if they were simply recalling all cars with the same batch number pipes, but if that were so, those details don't seem to appear on the pipe.  But then there appear to be many failures outside those ranges anyway.  I would like to know the answer, but long may yours continue to remain undamaged, just keep an eye on it anyway!

 

Neil

 

Neil, I am not trying to labour the point here, but if the recall you are referring to was the 2003 SEAT Inca van brake servo pipe, I have explained already that that type of pipe design and material is completely different to the pipe material now being used by VW group across its range of cars/vans. The Inca recall would be the same as the Ibiza and Polo of that period, ie 6K Ibiza and 6N Polo. As far as I know, that specific recall did only cover vehicles build over a period of a couple of years which indicates the acceptance that there was a material maybe batch manufacturing issue. This current type of "hard plastic thin walled" vac pipe would only be subject to a different recall, and as far as I was aware, having owned a Polo of that vintage for a period of 13 year - okay it was not a 1.2 so different pipe routing - I was never aware of any recalls being raised. It does not make what you have found on your daughter's car any different - but it does mean that if you raise an action against VW group, you can not list that earlier recall as being the same issue.

[Breezy_Pete]

Some photos of the vac pipe from NeilTM:

 

[Breezy_Pete]

[Breezy_Pete]

[Breezy_Pete]

[rum4mo]

In this case, do you think that it might be possible that a ham fisted garage/previous owner has had a go at replacing that one way valve and its diameter is just a bit much for that pipe, or the action of removal/fitting was not very well thought out?

 

I sort of tried that with my wife's previous Polo, and quickly saw that I might just damage that area if I did manage to remove and fit a new one way valve from another model, so I replaced the entire pipe on that 1.4 16v engine.  I'd think that on initial assembly of these pipes, some heat will be applied to the pipe to allow some "give" and then some "recovery" after cooling - as well as the pipe material probably being a bit more compliant when new and these barbs will only "bite" when you try to remove that valve.  My main concern when replacing that pipe in a feeble attempt to remove possible reasons for excessive oil usage, was that I would not be able to make good the retaining clip at one end as the original disappeared into a counterbore - I should not have worried as the service replacement was fitted with a better fixing method - so just needed to be pushed on.

[NeilTM]

Neil, I am not trying to labour the point here, but if the recall you are referring to was the 2003 SEAT Inca van brake servo pipe, I have explained already that that type of pipe design and material is completely different to the pipe material now being used by VW group across its range of cars/vans. The Inca recall would be the same as the Ibiza and Polo of that period, ie 6K Ibiza and 6N Polo. As far as I know, that specific recall did only cover vehicles build over a period of a couple of years which indicates the acceptance that there was a material maybe batch manufacturing issue. This current type of "hard plastic thin walled" vac pipe would only be subject to a different recall, and as far as I was aware, having owned a Polo of that vintage for a period of 13 year - okay it was not a 1.2 so different pipe routing - I was never aware of any recalls being raised. It does not make what you have found on your daughter's car any different - but it does mean that if you raise an action against VW group, you can not list that earlier recall as being the same issue.

The Octavia from 97/98 was recalled for this brake pipe fault in 2003. Our fabia is 2005. I accept that the Inca seems from what you say to be a different kind of pipe failing, but AFAICT it is the same type of pipe used on the Octavia.

 

Here is the link to the Octavia recall:

 

http://www.dft.gov.uk/vosa/apps/recalls/searches/expand.asp?uniqueID=6FC3E486C032E8D500256CDA0045B061&freeText=BRAKE%20SERVO&tx=

 

Here is someone on this forum experiencing the failure, and the type of pipe, if not the precise part numbers etc, can clearly be seen as something distinct from the Inca

 

http://www.briskoda.net/forums/topic/189386-split-vacuum-hose-to-brake-servo/

 

Better pics are out there of the Octavia pipe, but I have to be a taxi to a carless daughter RIGHT NOW!

 

Thank you for the caution though, Neil

[rum4mo]

That Octavia servo pipe picture is indeed not the same pipe as the Inca would have had, but it looks a lot thinner than the pictures of the current (split) servo pipe.

 

The pictures of your split pipe makes me feel a bit better about what is fitted to current cars - though hopefully without the splits, the picture of the Octavia servo pipe is really what I expected these servo pipes to be like as in wall thickness(thinness), so, maybe VW group learned a small bit more about servo pipes back then after they had made the quantum leap from the old school servo pipes to new modern (lighter and cheaper?) materials, and so it might go on!

 

Having a previously "car'd" daughter without a car must be a pain in your neck, my "car'd" one is coming back for Christmas, but a car with her name on it is ready waiting, the other one is also coming home for Christmas and is not "car'd" so is more likely to consider using buses!

[Breezy_Pete]

I wonder if it's coincidence that on the left side of the non-return valve there's an axial line of 'moulding flash' that lines up with the split (or has the pipe rotated, since it's presumably rather loose?). On the right side there's a zig-zag feature on the last barb that may also act as a stress riser? Click on first pic to enlarge it and see what I'm talking about.

 

I might pull my old one apart and see if the moulding flash line is less prominent in the barbed area (can barely make it out on the areas that I can see).

 

Seems the zig-zag bit is there on both sides, it's just not as obvious on the left side of your photo (nor on the top side of mine).

 

It does look like that flash is considerably less 'sticky-outy' on my NRV, not the best photo to show it though:

 

Edited 18 December, 2016 by Wino

[rum4mo]

I saw that moulding mark there and initailly thought that someone had cut down into that one way valve with a sharp knife, but after a second or so descided that it was just a mark from the moulding jig.

 

Edit:- totally unrelated, but I've just remembered that I replaced that hose because I wanted that car to be able to retain some stored vac after engine stop, that now u/s one way valve was stopping that!  I'm just correcting my original statement that I made in which I said that I replaced that pipe to try to sort an oil usage issue!

 

Actually that is one thing that I tend to do as soon as I get into a car, ie I press the brake pedal to make sure that it is not hard due to loss of vac - maybe doing that would avoid getting into this situation, ie early finding out of a pipe or other servo failure?  I do understand that I'll now get hammered with "vac is not meant to be retained" - but it has worked for me on my cars, and I did spot that failed one way valve in the Polo!

Edited 18 December, 2016 by rum4mo

[NeilTM]

I wonder if it's coincidence that on the left side of the non-return valve there's an axial line of 'moulding flash' that lines up with the split (or has the pipe rotated, since it's presumably rather loose?). On the right side there's a zig-zag feature on the last barb that may also act as a stress riser? Click on first pic to enlarge it and see what I'm talking about.

 

I might pull my old one apart and see if the moulding flash line is less prominent in the barbed area (can barely make it out on the areas that I can see).

 

Seems the zig-zag bit is there on both sides, it's just not as obvious on the left side of your photo (nor on the top side of mine).

 

I'm afraid I cheated and turned both splits round for the sake of one photo instead of two.  It would have been impossible, removing the pipe from the car to preserve that exact alignment up anyway, I'd have had to put the poor thing in a splint, LOL.

 

The split pipe from the one way valve that doesn't have the writing on it, ie. top right of my first pic, if you turn it round I just noticed the beginnings of a split in that side too, and it runs through the centres of the two red dots you mentioned earlier.

 

I can't tell if the very slight bur from the moulding seam might have excerbated the split, but if it did, then it was far too oversensitive to insult wasn't it? ;-)

 

Neil

[Breezy_Pete]

Splint. Very good. :)

[TrevorB33]

They do repairs kits for the brake servo, used as a recall on old 6n polos, I've used them on current 1.8t's etc,

I'll see if I can dig out a pn

Similar to this but they used to do straight connections too

http://m.ebay.co.uk/itm/VW-Polo-servo-pipe-repair-kit-6N0698998D-New-genuine-VW-part-/121256909384?hash=item1c3b799a48%3Ag%3A1mwAAOSw8oFXzotA&_trkparms=pageci%253Ae9722a0e-c544-11e6-8bb4-0050568f3dc8%257Cparentrq%253A12ea08901590a6a8f5606d74ffd70134%257Ciid%253A1

Edited 18 December, 2016 by TrevorB33

[NeilTM]

In this case, do you think that it might be possible that a ham fisted garage/previous owner has had a go at replacing that one way valve and its diameter is just a bit much for that pipe, or the action of removal/fitting was not very well thought out?

 

I sort of tried that with my wife's previous Polo, and quickly saw that I might just damage that area if I did manage to remove and fit a new one way valve from another model, so I replaced the entire pipe on that 1.4 16v engine.  I'd think that on initial assembly of these pipes, some heat will be applied to the pipe to allow some "give" and then some "recovery" after cooling - as well as the pipe material probably being a bit more compliant when new and these barbs will only "bite" when you try to remove that valve.  My main concern when replacing that pipe in a feeble attempt to remove possible reasons for excessive oil usage, was that I would not be able to make good the retaining clip at one end as the original disappeared into a counterbore - I should not have worried as the service replacement was fitted with a better fixing method - so just needed to be pushed on.

 

In a word, no, because the recall speaks of failure at all 4 points because of manufacturing defect, and what others have also experienced with no reason to assume rough handling or handling of any sort prior to visual inspection, and which is what tends to have been reported.

Your instinct not to attempt to separate the pipes from the one way valve were sound and for the reason you give that these are heat treated assemblies as you describe, and therefore intended to be fitted once, and not capable of being dismantled and put back with the same pipe.

If we are still speculating on reasons for the variable demise of these pipes, maybe variability in the heat treatment fitment itself has played a more significant role than subsequent operating conditions, or variations in the chemistry of the compound the pipes are made from?  VW are in a uniquely perfect position to know the answer to all these questions ;-)

If you look carefully at my pictures I think they reveal a brittleness to the plastic.  There are even bits missing, so the thing has actually crumbled to some extent, not just split.  It has no flexibility at all at those points yet it is called upon as a whole to flex, taking up movement of the engine against the static point of the servo mounted on the bulkhead.  I don't want to destroy the evidence, but I imagine that the ends would be brittle if stressed, and shatter to fragments under a hammer compared with the main run of the pipe, but that is also very stiff.  The approach to absorbing vibration between engine and chassis is intrinsically stressy on rigid, but thin fracturable material instead of a flexible neoprene type woven reinforced hose traditionally used without such issues.  Material not dissimilar to fan belts which undergo the most incredible number of extreme bendings back on themselves in the fabia in just one revolution!  It is to marvel that any material can do this without failing over kazillions of bendings, but it does.

Neil

 

[NeilTM]

I saw that moulding mark there and initailly thought that someone had cut down into that one way valve with a sharp knife, but after a second or so descided that it was just a mark from the moulding jig.

 

Edit:- totally unrelated, but I've just remembered that I replaced that hose because I wanted that car to be able to retain some stored vac after engine stop, that now u/s one way valve was stopping that!  I'm just correcting my original statement that I made in which I said that I replaced that pipe to try to sort an oil usage issue!

 

Actually that is one thing that I tend to do as soon as I get into a car, ie I press the brake pedal to make sure that it is not hard due to loss of vac - maybe doing that would avoid getting into this situation, ie early finding out of a pipe or other servo failure?  I do understand that I'll now get hammered with "vac is not meant to be retained" - but it has worked for me on my cars, and I did spot that failed one way valve in the Polo!

 

That's a nice little test habit - takes no time, but tests the brakes every time before moving - excellent idea. Should be compulsory on VW AUDI group cars then ;-) I might adopt it, although I suspect I don't have one on my Fiat as loss of servo assist is fairly instant if I stall the engine I noticed the other day. I guess the non return valve is there to retain some reservoir braking capacity after loss of or stall of engine. 

 

Neil

[sepulchrave]

The NRV is necessary to keep the servo assistance consistent, it means that the vacuum stored will always be the strongest vacuum your intake can generate because the manifold pressure varies during use.

[rum4mo]

I first found about about servos holding a bit of "power" after engine stopped back in 1978, I had just bought my first car with servo'd brakes and was helping a friend take the engine out of his SAAB 96, while he shopped for a (mini) block and tackle I queued on a steep slope waiting to get into a (full) car park. Initially things went well, I was reading a paper and using peripheral vision to see when to release the foot brake, after a few "moves" forward, things became a bit exciting!! Lesson learned.

 

Edit:- please note, a mini block and tackle with thin smooth woven ropes do not work well with oily hands, what a surprise!

Edited 19 December, 2016 by rum4mo

[NeilTM]

I have rebuilt and fitted the servo vacuum pipe with the aforementioned Pirtex which is £2.96p inc VAT a metre, enough to do about 3 fabias.  Not that penny pinching was the object, I'll leave that to VW, but it does put their price in perspective.  I checked out the spec as best I could.  The temp range of the pipe is -30C to 80C.  The rated pressure is actually 20 bar, the 60 bar is its 'burst pressure', but I didn't have that much information on my sample, LOL.  The 9.5mm(3/8") is the internal diameter.  This a bit smaller than the perfect or easy fit, but the half inch, the next size up would have been sloppy and needed clips.  These sizings seem to be standard throughout the industry, but with a water based lube that will dry out it was slow but not too much of a struggle to fit over the 'barbs' on the unions.  There should be other Pirtex outlets elsewhere, but if anyone is stuck I can post them what I haven't used.  At your own risk of course.  There do seem to be other satisfactory options available.  Not surprisingly the vintage car market is a potential source.

 

This is what's written on the pipe:

PIRTEX IAIR 20-010 9.5MM(3/8") WP 20 Bar AIR HOSE BSEN ISO 2398/BS5118/2 WWW.pirtek.eu 59B13

The job went very satisfactorily and I'm happy with it, but will of course keep an eye on it anyway.

I'm still waiting for my brother to get back to me with any further thoughts or tests I could run to find a wiring short, but visual inspection is fine as far as it can be visually inspected, and the wire between pin 80 on the SIMOS and pin 86 on the fuel pump relay had continuity and no connection to earth which should have tested the 17909 "fuel pump relay circuit short to ground". Of course if there is an intermittent wiring short somewhere, it may well do the same again, and I'm still not happy about that but realising this may be as good as it gets, as I don't see how professional auto electricians would necessarily find such a fault either.  Hopefully it might be a car again tomorrow.

 

Neil

[Breezy_Pete]

The rebuilt pipe. :thumbup:

 

Edited 19 December, 2016 by Wino

[NeilTM]

Well, its a car again, and one so over the moon daughter after surprising her by picking her up from town with it that they have gone off for a drive in it.  It will be nice to see them when they get back!

 

I suppose I should hit the marked solved button, although without knowing what caused the engine to stop, whether it is solved or merely waiting to intermittently hit again might only be determined by the passage of time.  The historical fault code claiming a ground to earth in the fuel pump relay circuit which has not repeated after clearing, and which cannot be found probing the wiring, if it is an intermittent, is by their nature notoriously difficult to find if not presenting since it comes down to a visual inspection of the wiring, which cannot be satisfactorily carried out, becuse of its frequent obscurity.   I am leaving her with a couple of replacment fuses, and I've marked the one to check if it happens again, since replacing it again might get her home, and then I would cut the wire out and replace it close to its ends, but that seemed rather drastic at this stage especially as there might be nothing wrong with it.  As for the vacuum pipes joining in the fun, well you know what I think about that, and I still intend to try to do something about that shocking state of affairs, and will report back anything significant here.

 

Just to recap the 'solution' if indeed it might be a lasting one, has been to replace the SIMOS (ECU) power relay, number 429 in big numerals on its end, located under the drivers side dash on the inside of the bulkhead. This was because it was found that the diode (which passes current only one way) was found to be short circuit from pin 86, and passed current between it and pin 86a in both directions as tested by the diode test setting on a cheap chinese multimeter, and then by putting a 12v car battery through a 21W indicator bulb just to be sure.  Both Wino and my brother thought this to be possibly excessive, so use a 5W or lower if testing this way maybe, but the multimeter diode test was reliable as it turns out. Also its associated 10amp fuse, number 14 in the fuse panel under the end panel of the dash against the door on the drivers side.  And of course to replace the defective brake servo pipes.

 

I would like to thank everyone who helped us in this long saga here, I doubt we would have got it fixed without you.  I just hope there is no sequel!  And daughter just returned safely with flowers for Mum and a bottle of something, and says thank you to you guys also.

 

I'm still here if there are any further questions or discussion, but for now at least, have a great Christmas.

 

Best wishes,   Neil and family.

[NeilTM]

On 20/12/2016 at 18:12, NeilTM said:

I suppose I should hit the marked solved button, although without knowing what caused the engine to stop, whether it is solved or merely waiting to intermittently hit again might only be determined by the passage of time. 

 

6 months, almost to the day and it did exactly the same as last time, blowing fuse 14 and its replacement I left my daughter with in case this happened again. Relay 429 serving the simos ecu unit has also gone in exactly the same way, shorting the diode, but otherwise functional.

 

Tested the wiring again for any shorts, with and without the ECU plugged in without finding any, so we are back where we started.

 

None of the ECU repair services inspire much.  One will bench test for 48 hours for £60 to reveal any intermittent faults, but since it took 6 months for the intermittent short, if that is what it is, to recur, what would give me any confidence if they failed to find an intermittent in 2 days? 

 

Unless anyone has any better ideas I might check over the simos board myself, looking for dry joints or any other signs of failure.  I had a look inside today as far as the back of the board as the breakdown guy said they can fill up with water, but all looks perfectly clean.  If that reveals nothing, I suppose I could just assume it is the wire and cut it off at the simos connector and relay socket ends (and relay socket to fuse) and solder in another wire routed through the bulkhead, but if I don't actually find whatdunnit my daughter, quite understandably does not want the experience of losing engine, brakes and steering in the middle of traffic again, and will want rid of the car I've spent so much time and money setting up with new brakes all round, exhaust, battery, tyres. It ought now to be good for several years, but for nothing much in all probability if I could just find what!

 

The brake servo hose repair however is absolutely fine - a proper job.

 

 

 

 

 

 

 

[Breezy_Pete]

Did it rain the night before or day of the failure?

[NeilTM]

On 22/06/2017 at 22:53, Wino said:

Did it rain the night before or day of the failure?

Hello old friend, hope you had a good Christmas!

 

It went on the hottest June day since 197?  I don't think it rained before that, and no more than a brief shower if it did.  The previous occasion was in Dec before anyone blames the heat for the identical fault.  The car had not been used for four days, and prior to that had been on a long run, as it had when it went in Dec, and is the only common factor apart from location I can think of..  3,900 miles since it last failed.  Both failures were on short local trips barely more than a mile from home.

 

I've written to ATP and ECU Repair describing the symptoms and basically inviting them to persuade me it might be worthwhile getting the ECU tested with them.  If they can either give it a convincing clean bill of health or correct a fault then that's either a fix or looking at cutting out and replacing the old wiring. Pile of new fuses and a relay on order!

[Breezy_Pete]

Hi Neil, it was good thanks, as far as I can remember! Yours?

 

I'll have another look at the wiring diagrams to refresh my memory and look at possible causes.