Starts and shuts down in 2 seconds - Resolved
#21
Doesn't it all point to an ECM related problem? It was replaced, messed about with, the dealer had problems programming it and the technicians will hardly be familiar with the car and its idiosyncrasies. I assume the thing about needing the old one to program the new one was because they needed the old firmware to load onto the new one but if the new one was slightly different in hardware terms whose to say the firmware would actually work reliably? Well, Jaguar of course but it's what 20+ years old technology? They probably lost the guys who really knew it years ago.
As a side question the control units are Jaguar made not subbed out to Lucas I assume? I ask as I know a guy who was very technical and senior in Lucas 20+ years ago and has a long memory.
As a side question the control units are Jaguar made not subbed out to Lucas I assume? I ask as I know a guy who was very technical and senior in Lucas 20+ years ago and has a long memory.
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CA Jag (01-20-2023)
#22
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michaelh (09-24-2022)
#23
Is this info and are these files available, somewhere?
And if so, would/could you link me to it?
Last edited by JayJagJay; 09-23-2022 at 09:48 PM.
#24
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Thanks, Don - yes they do now.
Should X105 read X103 or have I missed something on the model # increments?
@Jay - Use Don's links or they're both in the relevant forum stickies:- this one and X350/X358
Should X105 read X103 or have I missed something on the model # increments?
@Jay - Use Don's links or they're both in the relevant forum stickies:- this one and X350/X358
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Don B (09-23-2022)
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#26
#27
Thank you, Mike...
My experience with alternators is that if there is a failure or some kind of catastrophic alt failure mid drive, the car will continue to run on the battery power,,, until the battery no longer has the power to support the cars systems. I've never had a car that just died or shut itself down due to an alternator failure... But again, MeDumb,,, lol. And ain't afraid to admit it 😂
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LOL - I doubt it. More likely somewhat scatterbrained, which I can totally identify with
Doc, the modules are all Denso and, IMO, nicely engineered. A car isn't the friendliest environment for any electronic stuff.
I've been pondering (invariably dangerous) about the ECM relay mentioned by Don (in our cars, the one in the engine management fusebox). The ECM controls some of the power to itself (to allow certain actions after ignition switch off), and also to some of the engine management electrickery. This is how it is able to shut things down - for example, the injectors - when the inertia switch trips.
Doc, the modules are all Denso and, IMO, nicely engineered. A car isn't the friendliest environment for any electronic stuff.
I've been pondering (invariably dangerous) about the ECM relay mentioned by Don (in our cars, the one in the engine management fusebox). The ECM controls some of the power to itself (to allow certain actions after ignition switch off), and also to some of the engine management electrickery. This is how it is able to shut things down - for example, the injectors - when the inertia switch trips.
#29
I've been pondering (invariably dangerous) about the ECM relay mentioned by Don (in our cars, the one in the engine management fusebox). The ECM controls some of the power to itself (to allow certain actions after ignition switch off), and also to some of the engine management electrickery. This is how it is able to shut things down - for example, the injectors - when the inertia switch trips.
Does anyone know how frequently it polls the inertia switches for example. I'd assume (as an example) it wouldn't look at the inertia switches as a priority at start or while stationary but might do so by defaults every so often moving or not.
What might the ECM look at that could cause a shut down?
Personally I think the fact that it's a new ECM with old software could be a root cause. I have no idea what can be done about this but I have enough experience of computers to know that subtle hardware differences can play merry hell with software even though 'they shouldn't'. I recall the server that would reboot when you copied a large file - there was no way you'd expect this and that server controlled a steel mill. I wasn't terribly popular that day. They might have mentioned it.
#30
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I can't think of any reason why you'd want the motor to shut down immediately other than if the car thinks it's involved in an accident. Certainly wouldn't want that on a busy motorway...
Could still be an ECM issue, I suppose. Module config got a lot more involved for the 4.2. Have a look at the two posts from motorcarman here:
https://www.jaguarforums.com/forum/x...5/#post2495007
P.S. Don't ya' just love computers? Your story reminds me of an 'incident' in my younger days when using an early incarnation of MS software. I managed to copy the contents of a blank table over a populated one rather than the other way round. Happy days...
Last edited by michaelh; 09-24-2022 at 05:22 PM.
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Don B (09-24-2022)
#31
Hmm, just read that VID stuff from the link and I'm assuming the Jaguar tech guys wanted to read the configuration stuff from the old ECM rather than as I thought the firmware which it seems will be taken from a library of possibilities based on the VIN number.
I can't recall if we were told but is the new ECM the same code number as the old one? It must be or the Jaguar techs would have mentioned it. Using the word superseded would imply to me that if X supersedes Y then you can use X in place of Y and lose no functionality but I wonder if that's what was really meant in this context?
It also sounds fairly straightforward and non-destructive if stuff goes wrong in the various transfers.
I take your point about an interrupt rather than a poll - I think a little bit of CANBUS trawling is required, are there any messages that request an immediate shutdown? I guess there will be. There's some guy on the forum who knows a lot about CANBUS and wanted to hack it, I wonder if he is reading?
I was somewhat surprised to read that the display control module was a repository of data that other modules referred to. Also talk of weak batteries.
Where do you guys get all this deep technical knowledge?
I can't recall if we were told but is the new ECM the same code number as the old one? It must be or the Jaguar techs would have mentioned it. Using the word superseded would imply to me that if X supersedes Y then you can use X in place of Y and lose no functionality but I wonder if that's what was really meant in this context?
It also sounds fairly straightforward and non-destructive if stuff goes wrong in the various transfers.
I take your point about an interrupt rather than a poll - I think a little bit of CANBUS trawling is required, are there any messages that request an immediate shutdown? I guess there will be. There's some guy on the forum who knows a lot about CANBUS and wanted to hack it, I wonder if he is reading?
I was somewhat surprised to read that the display control module was a repository of data that other modules referred to. Also talk of weak batteries.
Where do you guys get all this deep technical knowledge?
#33
#34
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daro31,
I found an even more detailed summary of P1611 in an AJ27 DTC Summaries manual which may also be applicable to the AJ33:
Also, you might want to read the training manual section on the Denso 32-bit Engine Management System in the EMS training manual at this link (thanks to motorcarman and Gus):
Jaguar Engine Management Systems and Advanced EMS Diagnostics - Book B
Cheers,
Don
I found an even more detailed summary of P1611 in an AJ27 DTC Summaries manual which may also be applicable to the AJ33:
Also, you might want to read the training manual section on the Denso 32-bit Engine Management System in the EMS training manual at this link (thanks to motorcarman and Gus):
Jaguar Engine Management Systems and Advanced EMS Diagnostics - Book B
Cheers,
Don
Last edited by Don B; 09-27-2022 at 09:04 AM.
#35
I'm looking at two drives cycles with roughly a second each which makes 2 seconds. In both cases there is a reference to throttle motor - so what happens if the software senses a failure there? It can't be good but it wouldn't actually stop the engine of itself but the ECM might say hold on boys this engine's not going anywhere?
From an earlier document there was some rule about checking communications between modules and data errors. If the data between modules was found to be corrupt it would request 4 tries to get good data with about half a second between each cycle. It wasn't clear what would happen if that failed but it can't be good if for example the temperature control module fails that test or teh security fails the test. If the car knows it's not moving it can also work out it can safely stop the engine.
The more I look the more I realise the car runs on software.
From an earlier document there was some rule about checking communications between modules and data errors. If the data between modules was found to be corrupt it would request 4 tries to get good data with about half a second between each cycle. It wasn't clear what would happen if that failed but it can't be good if for example the temperature control module fails that test or teh security fails the test. If the car knows it's not moving it can also work out it can safely stop the engine.
The more I look the more I realise the car runs on software.
#36
We are certainly all learning an awful lot about this fault - I wonder if the OP is still here?
#37
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Don B (09-27-2022)
#40