C5 2003 BSI and ECU woes

[detheridge]

Hi folks,
I'm having 'fun' with my 2003 C5 diesel 2.2 exclusive.
At the beginning of December it sailed through its annual service and MOT. A few days later, it started playing up when starting - it fired up for a few seconds, then died.
My local (non Citroen) garage fitted a couple of sensors and all seemed to be well. The day after, it took eight attempts to start properly.
I drove 120 miles to Angelesey for a holiday, and I presumed that such a journey would blow out the cobwebs. The trip was uneventful.
Next day the fun really started - the car would not start and came up with 'immoboliser fault' in the display. I reset the BSI using the approved techniques posted here and the car started up immediately, but with 'anti-pollution fault' in the display. When I tried to start the car 10 minutes later, I was back to not starting and the 'immobiliser fault' display.
To cut a long story short, the car has been back at my oocal garage now for three weeks, and they appear to be stumped. Initially, everything seemed locked up, but they've managed to get their disgnostic box to talk to the BSI once again. However, the engine ECU is reported as 'locked'.
The car's only done 129K, but is it repairable, or is it well and truly knackered?
Many thanks in advance,

David (frustrated C5 owner who's never had this problem before)

[wheeler]

Do you have a second key to try?

[detheridge]

Hi Wheeler,
Yes, I do, and exactly the same result. I did wonder whether it might be low battery power in the keys, but I'm presuming that that's not the case.

[wurlycorner]

TBH it's rather difficult to suggest further on this one, without knowing what DTC's are being recorded in the ECU's.
Is the garage using the proper Citroen diagnostic software (Diagbox/Lexia) or an after-market diagnostic tool?

Just a clarification - when you try to start and it doesn't, does the engine crank, or not even crank?

Do you know which sensors they replaced and why (did they state a confirmed fault with them, or was it 'hit and hope'?).
If they were correct and they've gone after-market on the sensors, it's entirely possible that the replacement sensor is faulty (cheap chinese clone sensors can cause more problems than they fix, unfortunately).

As for this question:

The car's only done 129K, but is it repairable, or is it well and truly knackered?

Everything is repairable, it's just a question of time and money - even if one of the ECU's is borked, it would be possible to get it repaired or replaced etc.
The first starting point being correctly diagnosing what the cause of the fault is

[detheridge]

TBH it's rather difficult to suggest further on this one, without knowing what DTC's are being recorded in the ECU's.
Is the garage using the proper Citroen diagnostic software (Diagbox/Lexia) or an after-market diagnostic tool?

Just a clarification - when you try to start and it doesn't, does the engine crank, or not even crank?

Do you know which sensors they replaced and why (did they state a confirmed fault with them, or was it 'hit and hope'?).
If they were correct and they've gone after-market on the sensors, it's entirely possible that the replacement sensor is faulty (cheap chinese clone sensors can cause more problems than they fix, unfortunately).

As for this question:

The car's only done 129K, but is it repairable, or is it well and truly knackered?

Everything is repairable, it's just a question of time and money - even if one of the ECU's is borked, it would be possible to get it repaired or replaced etc.
The first starting point being correctly diagnosing what the cause of the fault is

Thanks for the questions.
As far as I know, the garage is using a generic aftermarket unit. Such are the problems you get with garages that state that they service all makes and models - not that that's a criticism.
When trying to start the engine, it cranks away but simply refuses to fire. I think they tried replacing the crankcase sensor but it made no difference.

Interestingly enough, when I had my car recovered from holiday, the recovery firm treied their diagnostic box (again a generic one) on my car and that came up with all sort of seemingly spurious error messages, such as overheating (when the car was stone cold after sitting for 10 days!) and other strnage things. My local garage gasn't mentioned anythign of that kind, so I'm presuming that those messages are no longer coming up.
Ho hum...

[wurlycorner]

Ok well if it cranks, then it kind of comes down to some pretty basic diagnostics work that most competent garages should be able to do - comms with all ECUs, DTCs stored, then checking fuel pressure, if injectors are being fired, MAF giving correct readings, if it has crank signal etc.
Even the 2.2 HDi is a pretty simple engine and control system in comparison to modern cars they'll be working on now.

If they aren't getting it though, might be worth trying a specialist.
Looking around, it seems there is a 'french' specialist not a million miles from you - no experience with them myself, but perhaps other forum members know them/can advise?
https://www.frenchcarsshrewsbury.co.uk/
I know it's more 'up-front' expense but you could probably get it transported to them for not a huge amount of money.
It is a very low mileage car and if the rest of it is in good nick, likely worth saving (but that's your call of course!)

[detheridge]

Hi wurly,
According to the garage they've managed to get communication with the BSI back up again, but the engine ECU is 'locked' and that's why it's refusing to start.
Others have suggested remedies as simple as a new battery (although the present one is only 2-3 years old?), or buyign a matchign BSI-ECU kit that is available on Ebay. Beign Citroen, there are at least 7 versions of this, soI have to try and find out what the parts numbers would be for my car. This latter solution was suggested by the french cars folks in Shrewsbury, while Chevronics in Hitchin (who certainly know their Citroens, said it could be somethign as simpe as a dodgy fuse.

[wheeler]

Hi Wheeler,
Yes, I do, and exactly the same result. I did wonder whether it might be low battery power in the keys, but I'm presuming that that's not the case.

The car should start without any issues even if the battery is removed from the key.

[detheridge]

Hi again folks,
Help is at hand thanks to Hannah Gleeson early C5 expert in the Citroen car club. He's been today to give my car the full monty via his Lexia and confirmed that the engine ecu is definitely mashed.
He's managed to clear all the surious stuff from the BSI and has goen away to try and source a replacement. With luck, my 2003 C5 will live again!

For any ecu buffs out there, these are the part numbers for the unit:
0281010938
EDC15C248
9646196480
If anyone has one of these available, please contact me off list.
Anyway, the interesting question arises: how and why do ecus go awol?

Thanks in advance for any info,
David.

[wurlycorner]

Absolutely brilliant news that someone has helped out and you know the way forward - that's great.

Various reasons why ECU's can die.
It can happen just with age (components die); water ingress; or short circuit/overloads on the circuits they drive, causing things to burn out; or surges that 'flash' the memory (corrupt the software).
Without taking the ECU apart to inspect, it's difficult to be sure.
But it would certainly be worth giving the cabling and connectors at the ECU a thorough inspection and checking all power and grounds are ok, before fitting the new one - just to be sure there's no obvious underlying fault that might corrupt the replacement.

[wheeler]

Help is at hand thanks to Hannah Gleeson early C5 expert in the Citroen car club. He's been today to give my car the full monty via his Lexia and confirmed that the engine ecu is definitely mashed.

How has he came to the conclusion that the ECU is faulty? Were any other checks done like VAN & CAN wiring etc. I dont believe anyone could confidently condemn an ECU using just Lexia. Can you get coms with the ECU & see live data? I'm assuming so as you can see it 'locked'.

Anyway, the interesting question arises: how and why do ecus go awol?

In my experience a 'natural' engine ECU failure on this vehicle is pretty rare, 95% of the time an ECU has failed on one of these it is external factors e.g. water ingress, incorrect jump starting or other human errors like allowing it to short to positive. Hence why im asking how sure the diagnosis is.

Also are you aware that you cant just plug in an identical ECU from another car? The ECU, BSI & keys are a matched set.
To use a second hand ECU you have a few options
1) Replace as a full matched set ECU, BSI & key all from the same car (please note doing it this way you could end up with a higher mileage if the donor BSI has more miles than yours)
2) Have the ECU virginised by a specialist, This would then need matched with Lexia (You will need your vehicle 4 digit security code for this)
3) Have the immo data 'cloned' onto the 'new' ECU by a specialist, this is only an option if indeed the data is readable in the first place & not corrupted.

[wheeler]

It may also be worth opening up the ECU casing to check for any obvious damage like water ingress, dry joints or even obviously burnt out/damaged components.

[detheridge]

Hi Wheeler,
HannahGleeson bought along a similar (but not identical) ecu and managed to get his Lexia talking to the BSI (somehow the garage had manaed to get the suspension down to zero). He managed to clear a lot of errors in the BSI, but thorough testing showed that the orignal ecu is u/s. He did hope to find an indentical one with the same part numbers, but that hasn't happened.
Your option 3 is the one chosen - he suggested sending the ecu to ecuconnection in Norwish, who do have an identical ecu and can clone the data on the original. I have to hurry on this one, as I've been drivign my garage's courtesy car around since December 27th and understandably they would like it back as they have customers waiting!
However, I'm running out of time and money on this, having had TWO new clutches (not my terrible driving; a former garage fitted the clutch which juddered like mad from the get go and failed totally after 4k), and a ton of other items over the 5 years I've owned it. If this doesn't work, I'll offer it tro anyone who can take care of it.

[detheridge]

Latest update: Hannah Gleeson recommended a company called ecuconnections in Norwich who can exchange your duff ecu, copy the data onto another unit and send it back to you.
The cost is around £100, and they did mine within three days (sent off on Monday, recived back today (Friday)).
The garage have just rang to say that my C5 now lives once again! I'll collect it on Monday and carefully test it next week to ensure that everything is working as it should.
Phew!!!