Hi!
I have a slightly weird hobby - which is collecting car headunits. And this time my patient is a headunit from a 2016 Jaguar XE (EU version). The headunit in question was made in 2015, and has a model name of NLI HU (which from my understanding is the "basic" variant). I also have a display and the display control panel from the same car. And I have a climate control panel is from a different car, same vintage though.

I found the official wiring diagrams online and wired the HU according to them - A13 to 12V, A11 to GND, then C5 and C11 to the climate control panel and C3 and C9 to the HS CAN (to which I also connected the climate control panel). And I also connected all of the wires between the climate control panel and the button panel. For the display I used an APIX display cable from a BMW - it fits (BMW also uses APIX) and the pinout matches. When I power on the power the current draw jumps to about 1A (which is expected), but then drops to 0 after a few seconds. If I press the power button on the climate panel, the draw again jumps to about 1A and goes to 0 after a few s. But I get nothing on the display.

I am assuming that it is missing something on the CAN bus. Usually some sort of ignition message or something. But that's just an assumption. I would expect it to turn on without ignition as well - at least partially. Anyone have any ideas?

Or, even better - does somebody have a CAN bus log from the HS CAN bus?

For illustration - the patient in question

 

Are you using 12.0V? If so, I’d turn up your power supply to 12.5 to 13V, see if that makes any difference.

 

12V, yes. Tried with 13V, no difference. Never had any issues with 12V either... usually car parts are very tolerant of different voltage. I think the label on the HU here even says 9-16V.

 

Yes, but Jags are known to be quite sensitive to low battery voltage. That was the easy thing to try.

 

I see. Good to know.

In the meantime I tried sending it some known JLR ignition CAN IDs, which have a similar effect as the power button - current draw rises to around 1A. Except that this time it doesn't drop to 0 after. But still nothing on the display. That kind of leads me down the path that the unit is awake, but waiting for something. I know that the amplifier is also on the CAN bus, but I am not sure if it is required for the unit to actually power on. I would expect not. So, yeah... CAN bus logs I think would be ideal.

 

I found this rather odd document in my Dropbox library, which you might find interesting…
https://www.dropbox.com/scl/fi/m9nfq...=bff2o7z6&dl=0

It’s from this folder of PDFs. I think they’re training docs for techs.
https://www.dropbox.com/scl/fo/dzifd...=qnitisnp&dl=0

This map of vehicle networks is very interesting, but unfortunately, I only have it for the 2014 F-type. Back then, the audio components were connected to a MOST ring, with the touch screen also on the MS CAN bus.
https://www.dropbox.com/scl/fi/r5j5t...=823cexph&dl=0

 

Hmmm, thanks for this. There is a map of vehicle networks for XE as well in the "MultiCAN Networks" document in that folder.
Sadly what I needed from that is mostly already present in the wiring diagrams anyways.

Looking at these docs... What I don't quite understand is the power button... why are there two? One on the climate panel and one on the surround around the screen. The "inControl Touch" document mentions that the one on the surround is "Infotainment system on/off". Says absolutely nothing about the one on the climate panel.

The Wake-Up document is interesting. But sadly those scope traces don't tell me much, and they didn't include the "fun" part - decoded data. They do mention an "AAM wakeup wire" though. AAM is the audio amplifier... but on the wiring diagrams I see nothing that would be a wakeup signal connected to the amp or the HU.

 

Well, I made some progress. A friend got me CAN IDs from Land Rover Discovery Sport, using which I managed to wakeup the instrument cluster (got it from the same car as the headunit):



Sadly those same CAN IDs don't wakeup the headunit. And the instrument cluster keeps rebooting - which usually indicates that either the message is not entirely correct or something is missing from it - which is totally possible since they were discovered using brute force.
Interestingly another person also brute forced an XE CAN IDs for their instrument cluster - and those don't do anything for my cluster or my headunit.

 

Did you get any closerwith this as im wanting to do the same with the radio & display (thanks for the BMW Apex tip , found cable and a BMW screen for Ł12.60 , obviously cant use the screen but the cable is good)

 

Not yet sadly. I focused on some other simpler headunits for the time being. But I did get the BCM and a matching key + the needed antennas. So in theory I should be able to get it going now. But I need to wire everything together and I am dreading that because I don’t have the connectors and Jag is being mean and used non standard pin spacing, so your regular pin headers don’t fit.

 

So, I have finally gotten around to wiring up the whole thing and… nothing. I get absolutely no signs of life from it. When I press a button on the key the current draw jumps up a bit, but goes down immediately and nothing happens. So I am either missing some wiring or some module, or the seller screwed up and the key doesn’t match the BCM.

I do find it slightly weird that there is only one fairly thin GND connection for the BCM, while there are two giant ones for the positive.

 

We are getting closer… so my no signs of life was just a bad connection. Then I got it into accessory, but couldn’t get ignition. I got SDD and was able to do the fix immo (or however it is called) and I am now able to get it into ignition…

The headunit however is not responding to SDD (and the front panel also) and I cannot figure out why. I also got the amplifier for the HU since it requires it, but that didn’t change anything.

Any ideas?