Main dealers sometimes essential - machika
I have just had an issue with our C5 when I would have been better off using the local main dealer from the outset. The car's engine management system was reporting an anti pollution fault and my first port of call, as is usual, was to consult the chap whose garage services the car. A subsequent visit to the garage and a diagnostic check resulted in a turbo overboost fault being diagnosed. He hadn't got much idea what would be causing this and three or four visits during about 3 weeks didn't solve the problem, as the fault kept recurring.

I had booked the car in again for today but I decided to ring the local main dealer for a chat about the issue, before risking spending money any more speculative work on the car. I was told it would be beneficial to take the car in to the dealer for a diagnostic check, as they have access to software downloads that indepent garages do not have. The subsequent diagnosis identified that the problem was caused by corrupt software and there was no anti pollution fault after all. A software download has (hopefully) solved the problem. The diagnosis and software download cost about £81, which is much cheaper than fishing around in the dark for the cause of a fault that doesn't exist.
Main dealers sometimes essential - mfarrow
I can believe it is true that main dealers can know there stuff better when it comes to electronics, especially as they have all the TSBs and software updates to hand. I don't agree though with the cost of upgrading this software - £81 to rewrite software in 5 minutes. Did they tell you it was an improved version or not? Any flash software that re-writes itself on the fly is trouble waiting to happen IMHO. User info should all be in RAM, so any 'bad settings' are easily cleared with a battery disconnect.

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Mike Farrow
Main dealers sometimes essential - bell boy
so there is an inherant fault in the software that the manufacturer supplied with the car and they want £81 to sort it? even microsoft update their programmes for free when they find a problem........
the futures here the futures dark.................
Main dealers sometimes essential - Roly93
so there is an inherant fault in the software that the
manufacturer supplied with the car and they want £81 to sort
it? even microsoft update their programmes for free when they find
a problem........
the futures here the futures dark.................

I agree with your sentiments, but you are forgetting one vital point, ie the power within the UK motor trade to do whatever they like !
Main dealers sometimes essential - cheddar
User info should all be in RAM, so
any 'bad settings' are easily cleared with a battery disconnect.



I would always consult the main dealer first in such circumstances because they have the TSBs and software updates, however £81 sounds a lot, I guess it is mainly labour. Was the software corrupt from new? If so a goodwill payment might be forthcoming via a letter to Citroen UK.

Although software updates and injector calibrations have to be done by the dealer many Ford issues can be cleared by a 30min battery disconnect, the ECU learning ability re driving style is also cleared and it has been suggested that it is beneficial to do this on a TDCi every few months or 10,000 miles or so.

Main dealers sometimes essential - machika
I would always consult the main dealer first in such circumstances
because they have the TSBs and software updates,


I have no idea whether or not the software was corrupt from new. I would imagine it wasn't, or the car would have produced more faults than this single occurrence in the last three and a half years that I have had the car. The £81 included the initial diagnostic check, for which the standard charge is £35 VAT.
Main dealers sometimes essential - machika
User info should all be in RAM, so any 'bad settings' are easily cleared with a battery disconnect.


A battery disconnect did not work.
Main dealers sometimes essential - bignick
Many of the newer Citroens (and I expect other makes) have "fly by wire" electrical systems with a central ecu which controls everything. As I understand it the supposed benefit is in a simpler wiring loom which saves weight and time in manufacture.

The downside is that electrical faults become harder to identify and correct without access to the correct diagnostic software which the manufacturers are able to copyright in a way that has proved impossible with "real" parts thus preserving customer retention to their franchised outlets. OK while vehicle is under warranty but I would hate to be trying to repair one of these in 10 years or so.
Main dealers sometimes essential - DP
Speaking as someone with an IT background, a diagnosis of "corrupt software" would ring alarm bells. How did it get corruptedm when and why? If ROM based software becomes corrupted, this can usually only be due to a hardware problem. In other words, I wouldn't be surprised if it happens again.

The idea that the system updates its "user" parameters by flashing EEPROMs constantly fills me so much with horror that I can't believe it's actually true. That would be a truly shocking piece of design from a long term reliability viewpoint. Even the best EEPROM's are only good for about 10,000 "flashes" before they die.

Every system I've heard of uses RAM and with good reason.

Cheers
DP
Main dealers sometimes essential - mfarrow
The idea that the system updates its "user" parameters by flashing
EEPROMs constantly fills me so much with horror that I can't
believe it's actually true.


I too wouldn't believe it was constantly flashing the EEPROM, but most microcontrollers have functions which allow the program code to be re-written by the program (!), and this is where I'm suggesting the problem might lie. If it was a hardware issue then I would expect more reccurances of these failues. It happened to a friends LG phone - one minute the flash program was there, next it wasn't, and this is the only explanation I can think of.

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Mike Farrow
Main dealers sometimes essential - madf
Another reason not to buy French cars:-(
madf
Main dealers sometimes essential - Ross_D
A very helpful reply there madf..... The only trouble is the ECU's in these cars are German! (Bosch and Siemens systems)
Main dealers sometimes essential - DP
Thanks Mike. I suppose thinking of it that way, it makes sense.

My background is in high end laser printers which I appreciate are quite different, but some of the principles apply. The engine microcode (which tells the printer controller board how to drive the hardware its bolted into) is part of a base firmware file which is fixed and doesn't change unless it is upgraded/downgraded to a revised level. The user parameters (preferences, resources etc) are stored on hard disc (not practical in a car, but RAM will do as power is theoretically never disconnected).

When the system starts up, the base code is always the same, and both lots of data are kept as two separate entities. Although the two interact as appropriate, nothing the user does to the machine can alter or re-write the base firmware.

Although what you say makes perfect sense, and sounds very plausible in this case, allowing user parameters to modify base code instead of being used to select which code to run sounds like a recipe for disaster to me. I'm amazed these failures are not more common.

Oh come back points and carbs..... ;-)

Cheers
DP

Main dealers sometimes essential - Aprilia
I have quite a bit of experience with petrol injection ECU's - although at least 5 years out of date now.
On the systems that I worked on the base code was stored in ROM and never modified, but the 'user parameters' such as long- and short-term fuel trim, nr. start cycles, fault flags etc etc were stored in battery-backed RAM. If the battery was disconnected then the ECU would have to re-learn the fuel-trims etc. I can't see any need to do anything different. There are long-term data (immobiliser codes, VIN number etc, injector calibration data) that might have to be put into EAROM - but they would only need to be re-written once or twice in the life of the product following major repair.
The tale of 'corrupt software' sounds like it might have its origins in a hardware fault. I wouldn't hold my breath on that one. £81 sounds a lot - mind you my local GM dealer charges about £50 to update their buggy factory software - which I think is a cheek given they are effectively correcting a 'manufacturing defect' and it only takes 15mins of technician time at most.
Main dealers sometimes essential - Red Baron
I too have experience with engine electronics - aircraft engines.

Programming or re-programming EPROMs is the easy bit. The difficulty comes with identifying why this had to be done in the first place. There are many factors that have to be correct before EPROMs can be spoken to. Some of the most difficult to root cause are the ones where the voltage drops out meaning that not all of the program is correctly loaded if at all. Depending on the part of the programme that has not been correctly loaded, the fault may not manifest itself for a long time. Also material defects in the EPROMs can over time and use cause a similar effect.

Best to keep the electronics as simple as possible and make the circuitry as sound as possible.
Main dealers sometimes essential - machika
It is too early to say whether the fault has been rectified long term. The longest the car ran without the fault recurring, since it first occurred, is about 4 days. If it gets beyond the next week without recurring, I will feel a little more assured.
Main dealers sometimes essential - Ross_D
With regards to "corrupt" software in the ECU, I think what they are trying to say is the orginal software was buggy and the new software fixed these bugs. If the software was corrupt, the car would not function at all. As a hobby I dabble with ECU tuning and one of the major drawbacks when altering the file is correcting the checksums in the data which is stored on the EEPROM when you make an update. Whenever the ECU is initialised, it calculates the checksum for the data which is stored on the EEPROM and then compares it to the checksum which is stored within the data. If these match, everything is ok. If they dont, the ECU wont go any further and will flag a code. My point is, if the software was corrupt, the checksums wouldnt match and you would have a dead car, it wouldn't go anywhere. Thus, in my opinion, the software wasn't corrupt. A bug (glitch) in the software could easily cause phantom codes.
With regards to the program in the ECU "re-flashing" itself, then thats a no-goer as well, certainly for the EDC15 and EDC16 systems used in the PSA HDi's. As somebody said, variables which are calculated are stored in RAM and the original program code stays intact.
Main dealers sometimes essential - jacks
One of my neighbours runs a 5 yr old diesel Pug 306 bought from and always serviced at a local Peugot dealer.

Recently it failed to start (don't know exact details) but eventually diagnosed by the said dealer as a "virus" in the ECU. Over £600 for replacement ECU, + labour VAT etc around £900 total.

The owner argued that - since the car was supplied by the dealer and had never been to any other garage - the ECU must either have been faulty when supplied or else it had become corrupted in some way whilst being serviced.

The dealer was adamant "These things can just happen".......£900 take it or leave it basically.

You are completely at the mercy of the dealer in cases such as this


Jacks
Main dealers sometimes essential - mfarrow
Recently it failed to start (don't know exact details) but eventually
diagnosed by the said dealer as a "virus" in the ECU.


.*********

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Mike Farrow
Main dealers sometimes essential - mfarrow
.*********


That'll teach me to check my post's gone through before leaving the thread.

A virus? On a car? They mean 'bug', surely? Except they don't like using the 'b' word as it implies an inherent fault, which of course it is, as opposed to a malicious attack. They probably think people will be relieved to hear that they've got rid of this virus before they car drives them over a cliff or deletes all their MP3 files!

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Mike Farrow
Main dealers sometimes essential - bignick
On the plus side at least the software is upgradeable - if it was burnt into ROM then you could be looking at regular replacement of on board computer at £500ish a go!
Main dealers sometimes essential - yorkiebar
And people wonder why main dealers get such a bad reputation too ?
Main dealers sometimes essential - machika
Just one question regarding the software, assuming it was at fault. Would it not be covered by the same warranty that covers the rest of the car? In other words, the manufacturer has no obligation to provide updates for free.
Main dealers sometimes essential - Aprilia
If the vehicle has a mechanical defect or design flaw that causes it not to run properly then the warranty would cover repair/replacement of the relevant part. I can't see why software should be any different.
Main dealers sometimes essential - machika
I didn't phrase my question very well. What I meant to say was that the manufacturer has no obligation to update the software for free, once the car is out of warranty, which our C5 is.

With regard to the comment about Microsoft earlier, they only provide updates for their software for a limited period and they certainly don't provide free technical service for their products for very long. The same applies to all sorts of software products for PCs.
Main dealers sometimes essential - machika
As I feared would be the case, the software upgrade has not fixed the problem. I went straight back to the dealer, when the fault occurred (after running OK for just one day) and had a chat to the 'technician' who worked on the car. I was very annoyed to find out that most of the information that I had given about the car's recent history, when it was booked in, had not been relayed to him. I told him that I was very happy with paying out £81 to achieve absolutely no progress in finding the fault, especially as he had said there was no anti pollution fault.

The car will be back there today.
Main dealers sometimes essential - machika
Forgive the typo, obviously should be ''I told him that I was very unhappy''.
Main dealers sometimes essential - mk124
No problem with typo, thought you were being sarcastic in you post. Computers like cars are fantastic when they work, dreadfull when they don't.
In diagnosing mecanical faults I can see that people there may be some guess work in replacing parts. Why on earth does this occure with software.
Main dealers sometimes essential - Roly93
I can't comment on how the software would become corrupted but share the scepticism of an earlier post on the subject also being from a technology background.
Most forms of flash memory or EEPROM type storage have limited numbers of read-write cycles before areas of the memory become 'worn-out'.
This is true of the memory sticks that people use with PC's.
It is possible that part of a program written to a bad or failing part of the memory could be the cause of such problems. However I would assume that a re-write of the software would avoid such areas of this memory and wouldn't neccesarily cause new problems.
Main dealers sometimes essential - machika
Since my last post the car has been back to the main dealer (last Friday) and I made sure the technician, I spoke to on the previous day, was made fully aware of all the releveant rececnt history of the car.

The problem would appear to have been cause by a split in a small rubber pipe, that was connected to an EGR valve (engine gas recirculation). At least that is what I am hoping it was. The valve is similar to the ones the garage I normally use had been suspicious of. The car has been fine since then, which is all I can say at present. He also carried out some reconfiguration work on the engine and I am pleased to say that he was as good as his word, as I wasn't charged anything for the work carried out of Friday.
Main dealers sometimes essential - Micky
My limited understanding is that EGR is pointless on UK petrol engines, it deals with NOx which is not a requirement of UK emissions legislation. EGR has been a problem for many Mundano petrol engines, the fix is easy and cheap ..... so it appeals to most Mundano owners. Not certain if EGR can be disconnected for diseisels in the UK.

ECU software should be open source, plug the laptop in and adjust everything.

A split pipe! Astonishing.
Main dealers sometimes essential - cheddar
My limited understanding is that EGR is pointless on UK petrol
engines, it deals with NOx which is not a requirement of
UK emissions legislation. >>


IIRC it also deals with unburnt hydrocarbons on the warm up cycle.


"Mundano" is just so not funny any more.
Main dealers sometimes essential - Micky
">"Mundano" is just so not funny any more.<"

Yes it is! I've had two and bought a third. The Mundano does what it should do, but no-one in their right mind would set the alarm to get up early on a summer's morning to go out for spin in a Mondeo.

Deal with unburnt HCs during warm-up? I thought EGR was disabled until the engine was warm? I am uncertain though, because uncertainty means that I am generally correct ;-)
Main dealers sometimes essential - cheddar
>> right mind would set the alarm to get up early on
a summer's morning to go out for spin in a Mondeo.


A few ST220 owners might disagree.

I use a motorbike for that however the Mondeo is pretty entertaing to drive, there are many, many cars that better deserve the tag "mundane".
Main dealers sometimes essential - Micky
">A few ST220 owners might disagree.<"

It's still a Mundano, it might be quick(ish) but the experience of reaching licence-losing velocities is tedious in the extreme. Hence Mundano.
Main dealers sometimes essential - Adam {P}
Noooo - don't speak ill of the ST220 - I badly want one as my next car. So badly that it hurts.

The noise they make is fantastic and they handle amazingly well for such a big car.

3000cc = :-)
Main dealers sometimes essential - machika
A split pipe! Astonishing.


What is astonishing, that it was a split pipe, or that the split caused the problem?
Main dealers sometimes essential - nortones2
It seems that an oversight that occurs when using diagnostic machines is that preliminary checks are not carried out. I don't know whether engineers on here agree, but an instructor (maintenance of industrial FLT) I was talking to recently was concerned that his technicians were often blind to the limitations of the dignostic test machine, and went on wild goose chases because they hadn't eliminated the possibility of mechanical or other failures before the test was run. His main concern was speed of return of the FLT to productive service. For the punter in the grip of the car trade its that, plus the cost of redundant and expensive replacements. I would have expected a check of vulnerable components at least, to ensure the system was in working order before the leads were applied! Maybe it pays garages to misdiagnose?
Main dealers sometimes essential - Micky
">What is astonishing, that it was a split pipe, or that the split caused the problem?<"

It's astonishing that it took so long for the technicians/fitters/mechanics to identify the problem. That's doesn't mean that I would have spotted it though!
Main dealers sometimes essential - machika
I wouldn't know how easy it is to identify a small pipe like the one that was found, as there are a multitude of them on an HDI. The chap who services the car ruled out a split pipe, on the basis that the fault only occurred above a specific speed and didn't recur straight after the fault had been cleared. It always took at least a day for the fault to recur. I imagine the techician at the main dealer had a bit more experience in dealing with this kind of thing on C5s.
 

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