Hey everyone, I’ve owned this car for the better part of 4 years now. About a year ago I parked it in my driveway, and the next day I came back, tried to start it and got no crank. I’m completely lost as to what happened.

I’ve done a lot of research and tried to figure out what’s going on but I haven’t found any similar cases online. I hooked it up to an OBD2 reader and got 19 codes off of it. I erased them but to no avail, as soon as I took the scanner off and tried to start it the codes re-appeared.

I’m going to try and post a link to a video demonstrating what happens and also pictures of all the codes. I would really appreciate help from anyone with knowledge or ideas to impart. This is a project for me and it won’t be fixed or complete immediately. I’m looking for ideas or things that I could try in order to diagnose the problem and hopefully solve it. The car has sat all winter covered, and with the battery unplugged and on a tender.

It’s a new battery I purchased last year and the voltage reads 12.38. It’s fully charged and my battery charger has a tester that says it’s good. I’ve tested it with both key fobs and neither work to start it. I’ve tested all of the fuses and relays but I’m willing to do it again just to double check. I checked all of the earth pins for bad connections and they all looked fine. No rust or corrosion on them. I am out of ideas. Like I said before, I parked it one day, came back the next and it had gone completely haywire. Im good with the mechanical aspect to vehicles but when it comes to electrical I’m completely out of my depth.

Thank you for your time and I will be routinely checking this thread in hopes of finding a solution. I will provide updates and respond to as many people as I can with whatever time I have available. This will more than likely take a few weeks due to my job requiring the majority of my time, but I’m 100% set on fixing it. I can’t bear to look at it sit in the driveway any longer.

This is a link to a video demonstrating the no crank no start key turn.

https://youtu.be/3Lv5neoY9Ig

if the link doesn’t work, try copying and pasting it into your website bar.


This is a new code I haven’t seen before.

 

high speed can down

 

Without having done any research myself on the CAN Bus system, is it repairable? I had wondered if that’s what it was but again I’m no good with electronics. I’m ready to learn but I need to know where to start with this. Is it something I can fix by hand? Or do I need a computer to do it? And in what sense do you think it’s down? A chewed or cut wire? Or something worse.

 

watch this start to finish

then watch everything else on his channel until you start to understand how it works

 

Although the CAN bus is down for a lot of your readings it does work at times to obtain a few results. I would still look for poor/low voltage. Your battery is not fully charged at 12.38v. However it is high enough to not trigger your faults.
What does your reader indicate voltage is at OBD port? You may need Jag sw or equivalent to see which modules are actually off line and what voltages are present. Do any lights dim when you try to start it or is there absolutely no change when turning the key? With key on how bright are you headlights?

 

high speed is dead as a doornail without comms to the instrument cluster and prndl status it will never start…

on an 04 you pull ecm dtcs off K

 

I would go with OldKarz's diagnosis and rule out the battery first.
If voltage breaks down then all the little gizmos that communicate over the CAN will go starving and call for help. So many of these errors may very well be the result of your battery breaking down under load (i.e. switching on the ignition and activating the starter).
I suggest to test with a proven fresh and healthy battery. The errors you will read then are the real ones and not the collateral damage you seem to see in your current reading.

Also new batteries may die rather quickly when something else is wrong. I had this issue some years ago, when some wayward control module would wake up the CAN when the car was parked. I couldn't let it stand for 3 days, it wouldn't start afterwards. I found that when you shut down the car there will be still more than 1.6A flowing for up to 15 minutes, then goes down in steps when module by module is going to sleep. It takes around half an hour after you park and switch off the car until all of these electronic gremlins have fallen asleep.
If now, like in my car, some module erratically comes to live at night in the garage they will all wake up and jumo to 1.6A again, taking half an hour again for the last of them to fall asleep. This happens several time over a parked day and the battery is dead very quickly.
Jaguar Classic in Germany were able to fix that by reworking the messed up cabling around my OBD port in my case.

 

There is no change in the headlights when I turn the key. And they look to me as bright as they should be under normal circumstances. All cabin controls function. Have not had time to check OBD voltage. Will update later today.

 

Thank you for sending that video! It helped me understand the CAN system much better than anything else I’ve ever seen or read. It also gave me a few ideas for testing it myself. Before I play around with it I’m going to take a look at the 200 page X350 wiring diagram. I’m hoping to find the CAN Low/High wires coming off of the ABS module. I want to confirm that the wires themselves are still intact, and then eventually I want to try diagnosing the cause of the problems. I will continue to watch the videos you recommended in hopes of learning as much as possible.

 

I will definitely keep this idea in mind. For the time being I’ll take the battery to NAPA and have them test it since their equipment is probably more reliable than mine. If it’s good as I believe it is and they’re willing to do a trade in then I’ll get a new one. But if not, im not going to pay the 120$ price tag for a new batt right now. Im fairly certain the issues im having are due to exactly what xalty is saying, just based off of my own previous research and observation. But I will try everything just in case, and I appreciate all of your guys time and help.

 

Given those symptoms, the first thing that I would do is to clean up the battery terminals as you'll certainly want clean and snug battery connections. Otherwise, you'll just be chasing your tail trying to nail down the problem.

 

Typically on our Jags the CAN wires are solid green and solid yellow.
According to fig 20.1 in the schematic the DSC module has three CAN pairs connecting to it as it is acting as a hub.

So on plug EC30 (at the DCM module):-
Pins 12 and 14 are CAN connections back directly to the ECM, Adaptive speed control module and transmission control module.
Pins 25 and 29 are CAN connections back to the Yaw rate sensor alone.
Pins 11 and 15 are CAN connections back to the Climate control module which then passes along to the JGate module and then onto the instrument cluster.

If you suspect a bad wire, then you can always use a multi-meter on ohms to check the continuity between modules as a first basic integrity test.

 

This is great information. I apologize for the late response. I’m going to give this a try hopefully tomorrow as the weather here is rainy today. Thank you for taking the time to look at the wiring schematic! I’ll update as soon as I’m able to.

 

So the weather cleared up and I was able to test the DSC module wires. 2 of 3 gave readings and one was completely open. I’ll post pictures of the readings. The resistance on the two that I have a reading on, seemed way too high.

The multimeter did not beep like it normally does when you have continuity on any of the 3 connections. Any thoughts on where to go from here?

Pins 12-14


Pins 25 and 29


Pins 11 and 15

 

Typically you want to measure each wire independently for continuity, whereas you are currently measuring across the pair which is a fallible test.
I would use the ohms setting (200) on your meter as you are looking for resistance measurements alone one piece of wire that will be 2 ohms or less.
The setting you are using is the diode and continuity test function. It usually doesn't give you an actual resistance reading (typically gives you the forward bias voltage reading across the diode junction).

Now the practical issue is getting your meter probes to reach both ends of the same wire (as they are terminating at different module locations).
To cheat this you could put a wire link between the green and yellow wires on one module plug and then measure the resistance between the yellow and green wires at the other module destination plug in the loom, that way you are measuring both wires simultaneously as one longer wire circuit loop. An open circuit result tells you one or both wires is faulty, you then need to figure out which one (you could link either yellow or green to a other wire that goes between the two target plugs and test again to work out which of your original wires is open).

The resistance reading you are seeing is probably the termination resistor that is present in the module at each end of the CAN wiring structure. Remember in the video they spoke of the wiring needing to be terminated to stop excess energy reflecting back into the CAN communications. By measuring just between the yellow and green wires as you have, you will get an open circuit if one of your wires is faulty, or if you have inadvertently disconnected the module that is providing the CAN termination resistance.

 

100 or 109 ohms isn't far from the 120 spec for each CAN terminator.

It may be the module with the other terminator is not connected ... in which case you get to figure out why (sorry)

CAN's fairly tolerant so 100/109 is probably good enough if you get the other one connected as well.