2016 XJL. VIN SAJWJ2GDOG8V99409. - mileage: 33,275

In addition to my intro post, I have included the dealer notes on my invoice which served more to add to my confusion. Any advice or direction is sincerely appreciated.

Dealer Notes:



“Determined faulty module. Ordered and replaced module, found module failure to program and need to open TA case for assistance on programming. Per Techline, replace GWM/CJB to repair issue. Part is backordered, customer taking car as is. Sub-total: $2375.73”



“Installed C2D49763 :Panel-air CON/RA. 1 @1059.95

Unrealized C2D49515 :Module-Elec Con 1 @325.78 - Ordered

Installed C2D49763 Module-Elec Con 1@40.00 Confirmed complaint, Found AHU



Found AHU software outdated and needed update.

Unable to perform SOTA update without update using SDD. Performed ADU

Phase 4 Incontrol Touch Software update to newest level. Once completed , needed

to finish using SOTA. Found SOTA unavailable due to faulty TCU. Recommended

TCU next. Also found FCIM offline still. Verified fuse in CJB is not expired. Next,. Checked for power and ground at Connector C2ME14A-1=0.6mv, C2ME14A-10=14.38V. Found power and ground OK.

 

Wilyum, from what I am reading, it sounds like you are having a CAN bus issue and the modules are not able to talk to each other. This is where they are not sure if it is the A/C/radio that is the problem at the moment or if you may have a bad transmission control unit. Wehn they replaced the A/C module, it also has your radio stuff in it too, hence why you are seeing it also trying to update your Incontrol Touch software.

What you have to imagine is the game of telephone that you played as a kid. BUt, in this case, you have 2 lines of people. So, lets say that you have 2 rows of 10 people. Each pair of people is a module. If all the people are facing the same direction, one row of people are going to pass the information to their right. The other row of people are going ot pass the information to their left. So, if you have a bit of information, it it going to go down to one end where the pair there is going to pass it to the other row and start it going down that row until it reaches the end. Then that pair is going to transfer it to the original row and have it start its loop again. so, around and around goes the information. Now, you have ot imagine that you have 1,000s of bits of information that is going around in a circle. Each person needs certain bits of information so they can do their function. But, they also still need to pass on the information to their buddies so their buddies can use the info too. If you break this chain, modules do not get their information and they do not know what to do. Hence where you sit now. This communication link between everyone is broken somewhere (most likely between the TCU and the A/C module, but the question comes, is it the TCU not able to hear, or is it not able to speak, or is it the A/C module unable to speak or hear. Not always easy to figure out. Since you have the OBD port (where the technician's computer is inputting data to see what is going on) is in this chain of people, if you have a break, it may not be able to reach the module that got replaced to program.

Hopefully my example makes sense to you to help explain how the modules talk inside the car to each other. It sounds like the tech is on the track to getting to the problem, but he is also being hindered by the fact that he cannot get all the parts he needs.

I think you need to be patient and hope that the module arrives in short order to minimize the time your car is out of order.

 

Thank you Chris. Your "Telephone game" example helps somewhat but this 83 year old brain still gets a bit rattled attempting to make sense of computer tech stuff! One would think that an organization like Jaguar who designed these systems would have at the same time developed the capacity to get and keep them on track if and when they go awry. Speaking of Jaguar, the Organization, do they have programs and systems in place to support people like us and the techs working on our behalf with the computer "hiccups" that result in our total loss of a functioning vehicle. Its not like we could have contributed to this type of malfunction by not pay attention to mandated scheduled service issues. I apologize for getting off topic....Thanks again for your input!

 

There is no support for people like us. They want you to buy new cars and throw away what you currently have.
Keep reading and you will find it's VERY common for dealers to refuse to work on cars over 10 years old! Yes a Jaguar dealer refusing to work on Jaguar cars!

Next the modules come in many versions and some are not compatible with others. So now you need to stock multiple versions of the same parts. Very expensive.
This entire system is designed to squeeze out the DIY people and the aftermarket repair places. It's doing a pretty good job too!
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Thermo,

I'll be totally honest here, that is the best description of how a CAN bus network works I've ever read!

I'll give you another example of a CAN bus at work;

In a combat jet I used to fly, the CAN bus connected virtually everything on the jet, radar, missiles, HUD, HMS, engines...you name it. As we added more and more capability to the aircraft we noticed an increase in computer glitches.
It transpired that we were running the main computer at 270% capacity! The flight control (thankfully), were running in a protected area of the main computer. However, sometimes we would bust the computers limit.....we added a new computer to help.

In normal operations, the BCM doesn't even get close to 50% capacity, sometimes, (and I'm guessing), it overloads.

wombat

 

Wilyum, lets see if I can help you understand things with a different way of looking at things. Imagine 10 people sitting at a round table where the table spins. There are ***** on the table that are stuck to the table, but you can remove them if you need to. But, you can only hold on to one ball at a time. If you assign everyone a number going around in the circle, people 1 and 10 are going to be working together to get certain *****. People 2 and 9 are going to be working together, 3 and 8, 4, and 7, 5 and 6. Each pair of people is a computer in your car. Each ball is a tidbit of information that your car can use. Person 1 is the boss of everyone. So, lets say you are playing the engine computer. So, every ball that comes by and it has some tidbit of engine information on it, you need to grab it and update that tidbit of information with what is happening right now. Now, remember, you can only hold 1 ball at a time. So, you are going to grab it, figure out what that tidbit of information is, update it, then put it back on the table so you can grab the next ball. Now, your friend the tranny is going to grab the ball that you just had so it can then see what you wrote so it knows what gear to put the tranny in. Your friend grabs the ball, reads it, puts it back down. Now imagine all 10 of you are constantly grabbing these ***** and either just reading the information (as you only need to know what that tidbit of information is) or you are having to update it so someone else has the tidbit of information for them to read and use. Around and around all these ***** go with little bits of information. One ball will have the timing of the engine, one will have the outside temp, one will have the load on the engine, one has the amount that the body is leaning. You have thousands of these ***** on the table going around and around. As long as everybody grabs a ball and puts it back, all is good.

When things go wrong, think of it as a pissed off worker. that worker just starts taking all the ***** and throwing them on the floor. What information is the guy next to him getting? NOthing. Now, this guy is going I need to put some information out there, so, he is going to start finding ***** and putting what he knows on the ***** and putting them back on the table. But, there is a lot of information (*****) that are missing and therefore, he cannot do his job. The person next to him is getting very little information (only what this one guy is giving him) and therefore can not do their job either. Only when it gets around to the partner of the pissed off guy does all the information come back on the table as their partner is busy picking up all the ***** from the floor and putting them back on the table. So, how many people are affected? If it was guy number 4 that was pissed off, then only people 5 and 6 are affected as 7 (4's partner) is putting all the information back on the table. But, if it was say number 2 that was pissed off, then 3, 4, 5, 6, 7, and 8 are affected. Person 1 (the boss) can see this pissed off person and is going to start throwing up a flag (the little error light you get on the dash) indicating that he has a problem and needs someone to deal with this pissed off guy. Everyone at the table is going to do their best to do their job, but without information, they can only do so much (this would be the limp mode that cars fall into in some cases).

Hopefully this makes a bit more sense for you to picture the flow of information inside of the car. Lets just say it gets a lot more interesting when you start thinking about there being multiple tables, but the tables cannot talk to each other (one is speaking english, another is speaking french, a third is speaking spanish). But, the spanish table needs some of the information that the english table has. I will save how that happens for another time. Stick with understanding how just the one table works first.

 

Thermo, Thanks for the explanation on the functions and problems. The real issue is my not comprehending why, when the module ceases to function, we can not find a replacement part, install the new part, and be back in operation? Just doesn't make sense to me. For instance: If a fuel pump stops pumping fuel and cannot be repaired, purchase a new one and replace the defective one. If s starter motor no longer starts, purchase a new one and replace it. I know things are not that simple in this modern "Computer Age" but it escapes all logic that a sophisticated, costly, machine like my 6 year old, 33000 mile XJL is a throw away because of a non available replacement component part. It is inconceivable to me that the intelligence capable of designing and building a system of "smart" modules that speak to one another in the complex way you describe, didn't at the same time, design a system to repair and keep them functioning! I apologize for going off on a rant....just frustrated! Bill

 

Wilyum, I can understand the frustration. You would think that Jaguar would keep these parts on hand. Granted, Jaguar is mandated to for a period of 10 years from the creation of the car. It is a federal law as I recall. It was to prevent things like what you are experiencing (preventing the automotive manufacturers from making a car, not carrying a vital part to force you to buy another car). WHat you may be experiencing is what I will refer to as a double fault. In the computer world, one module fails and sends a jolt of electricity down the line to its budy and takes them out too. Most technicians are taught that there is only "one problem" to fix. They are not taught how to think about what failed and what else did it take out. You normally don't have a starter fail such that the gear remains engaged and then tears all the teeth off of the flywheel. Not one of those things that you normally hear of. But, it does occasionally happen. So ,a new starter would not necessarily fix things. This is where your tech should be able to get some codes that will lead him to the location of the information drop and then you have to look at the computers on both sides of that drop. If you can talk to your tech and get the codes he is seeing, some of us here have the same books your tech has and we can provide some help. We may be able to diagnose the problem for you.

I know this may sound absurd, but try looking on a place like E-bay or co-part.com and see what they may have. Those places have used computers that yo ucan get and they may have what you need.

 

Another thought try a breaker such as Pacific Motors in the Detroit area or Jaguar Heaven in CA. Good luck