I bought a pristine XJ8 only to discover the ECU had been changed in the past. This means the car VIN is different to the ECU VIN. The car runs beautifully but the Jag analyser cannot interrogate the fault codes on the engine. Obvious solution appeared to be to replace the incorrect computer with a new one but I am being told this will not be possible as the Jaguar system will first require to interogate the computer already in the car and this will then be used to reprogram the new computer. This means the wrong VIN will be transferred to the new computer. i.e nothing is gained and the car has zero resale value as she stands with a mismatched computer. The original computer is not available. Can any one with experience please comment on this? Trennie
So what problem is this currently giving you ?
Dash light on ?
All ECUs are the same, it’s the suffix which is model dependant as it indicates how the PROMS have been programmed.
As Andy has said “if you don’t have a problem DON’T try and mend it”!
Just drive and enjoy your car.
Hi Andy.
At the moment the car runs without fault but it is not possible to interrogate the ECU for DTS codes. This is because the VIN number on the installed computer is different from the VIN number of the vehicle. I was not aware of this when I purchased the car but now have become aware that it will be a huge problem to see the car with this mismatched ECU.
Cheers
Tom
Hi Neil.
Many thanks for your swift reply which is most appreciated. If only it were so simple.
Because the ECU which has been installed has a different VIN # to the car VIN # this means the ECU cannot be interrogated to determine any DTS codes or to assist with diagnosis. This means that the Canadian DOT (Department of Transport) are not happy with the mismatch and are asking me to get it sorted out. It also means that safety inspections cannot be dependent on simply a plug in to the DOT system and must be done manually at additional expense and waste of time. I am willing to invest in replacing the ECU with a brand new one from Jaguar but have been informed the process is the car is connected to the Jaguar System which downloads all information from the installed computer (including the incorrect VIN) and then reinstalls all setting onto the new ECU when it is installed. In other words; installing a brand new computer is completely useless to resolve the mismatched VIN numbers.
Rgds
Tom
Well you need to get the jag dealer to talk to jaguar uk then.
Hi Andy.
Many thanks for your follow up. Correction on my last reply to you; it should have read “ a huge problem to sell the car with this mismatched ECU VIN”
I have the impression the Jaguar agent here is giving me the run around and have attempted to go direct to the UK. So far I have not had any success at all hence my posting on Jag Lovers.
Again my thanks to you and others expressing interest Andy.
Rgds
Tom
This may be useful to read:
http://jimbutterworth.co.uk/8ecu.htm
I don’t have any experience of the WDS/PDS etc. but I’m sure that Bob (motorcarman) may have a clearer view:
Just get a used part from a salvage vehicle that is the SAME as yours.
The list of PROMS is in the Recall T493/R493 if the procedure was carried out during the campaign you should see the part numbers on the case and PROMS
I’m pretty sure almost all the ECMs are the same, it is just the PROMS that are different for models and years.
Here is a copy of the Recall we did in the late 1990s/2000s
05-1-26am5 1995 MYRecall R493.pdf (256.2 KB)
bob
That TSB is 2 generations out from the car in question. Things have changed.
Yes, later ecu’s hold the VIN and milage in many electronic modules.
Cheers Andy my ownership of a X308 was a short one due to Nikasil, but an expensive one. Other than getting all 4 tensioners replaced prior to a Blow By check, I didn’t get into the Nitty Gritty!
Trying to unscramble the intricacies of the S Type since my cherished X300 was totalled last year.
Hi Bob and Neil.
Thank you so much for your kind replies but it would appear I have not clearly stated the problem. This car already has a salvaged computer from a donor car and the car functions properly. The problem is that the donor car computer has a different VIN from my car VIN. This being the case, Jaguar are reluctant to work on the car, Canadian DOT are not happy with the mismatch and added to this is the fact that the donor computer cannot be interrogated for any diagnostics related to the engine or other systems. Jaguar tell me this is because of the mismatched VIN’s I do regret I have no idea what animal is a PROM?
To resolve this dilemma, I presumed that a new computer direct from Jaguar be installed albeit at considerable costs. I am told this will not work as the Jaguar system firstly takes all settings from whatever installed computer is in the car and transfers this directly to the new computer. If so, the Jaguar system will simply transfer the incorrect VIN from the donor ECU and I am back to square one presuming this information is correct and not just another fob off from Jaguar. If anyone has experience with such as this or if this information is incorrect, I would sure be much appreciative as right now I am going around in circles with a beautiful XJ 8 which I cannot sell or resolve.
Kind Rgds
Tom.
Hi Andy.
Yes indeed and that is the problem. When an analyser is connected it comes back with an error message to say it cannot connect to the ECU. Jaguar tell me this is because of the VIN mismatch on the donor ECU. Apparently Jaguar have no solution to this, or so I am told?
Rgds
Tom
Maybe these may have information that will help you.
PROM: Programable Read Only Memory it’s an Intergrated Plug In Module in computers that can be reprogrammed.
Doesn’t the OP have an X350
But yes, this is the sort of thing the OP requires.
A workshop procedure to tell you how to change the ECU
The only person on J-L that knowledge of ECU remapping appears to be Andy Stodart and he has been conspicuous by his absence since J-L changed to the new site.
Don’t know where the OP is based but in the UK there are companies that repair and remap ECUs, also due to the number of different models on this Forum (X300) it is helpful to know the year, model and in many casesthe VIN.
Hi Neil.
I also was absent from the site for several years since the changed from the well respected and user friendly Jag Lovers. I joined in the mid 2000’s from Singapore along with Nigel also from Singapore. My original special jag in Singapore is no more and I have moved to Canada, bought a later model XJ8 2005 (X350) and now deep into the nightmare. It is certainly a source of intense annoyance the way Jaguar just change things for no apparent gain and most certainly not to the advantage of those who love the mark. I would need to say this arrogance is apparently a corporate culture. I swore I would never own another one but here we are. I have all the details in the world but to no avail in this age where a pristine fully functional car is at the mercy of a view diodes and resistors all because of outrageous and misguided techy nerds. I am coming to the conclusion that scrapping this pristine car is probably on the cards as so far nobody has answers that satisfy the need to sort out a simple ECU. Of particular concern is the Jaguar agent is as much in the dark as anyone else and has not the slightest intention to be of assistance.
Not being up to date on the tech lingo, what is an OP?
Rgds
Tom
Hello again Neil.
Upon looking at your below post again, perhaps a company in the UK who could remap my ECU to include inputting the correct VIN would be a viable option. Do you have any that you could recommend?
Cheers
Tom.
OP is original poster AFAIK.
I don’t know of anyone offhand but I’ll check and let you know, what verient of X350 do you have? Engine type and also the VIN # so that I can identify the ECU Part number etc.
Don’t think about scrapping it! Wish I could have found a decent low mileage one here in the UK, then I wouldn’t have had to settle for a S Type although the car growing on me it’s not a Jag and does not have an AJ16 lump.
Tom it is looking a bit bleak at the moment but does appear to be a known issue and it is being workred on.
I’ll keep trawling the net.