Model: 2015 XF 3.0 S/C
Issue: Trunk is not opening (most likely a damaged wiring harness and not the latch)
Part #: C2Z19978 (wiring harness)

The trunk (opening function) suddenly stopped working - The release button by the fog light switch isnt opening the truck, neither is the button on the key fob and same is the case with the switch under the chrome piece on the trunk. The emergency key blade does work.

Note:
- The trunk latch was replaced 6 months ago due to malfunction with the soft close function.

- The reverse camera intermittently stops working, displaying the message "Camera unavailable please contact the dealership"

I read up on some forum posts and learned that it's most likely the wiring loom that run from the trunk, through the loop by the trunk lid hinges and into the trunk lid itself. Some posts suggested it could be the latch itself.


I have not investigated with a current tester, but there is no audible sound from the trunk latch from using any of the 3 switches (in shut position and open position).

I'm due to purchase the wiring loom from the dealership today and hoping that is the fault as opposed to the trunk latch or worse a wiring harness besides the one mentioned as I imagine a lot of trim removing will be required for access.

If anyone has experience with the repair, please let me know what I need in preparation for the repair besides common tools and wiring harness.

 

If you want to quickly test before replacing the whole harness, you'll see a black rubber boot next to I think the right hand hinge. Pull it back to reveal the wires below (think you need to cut a small piece of rubber that holds it in place). You will likely see one or more wires broken. You can quickly splice them back (and insulate) then test it. A few people have done that as a permanent fix, but if your camera is giving tissues too that's a coax cable and you are prob better off replacing the loom

 

Hi Zereldo,
I had the same problem when I first bought my XF SV8 back in 2013. The problem was a broken wire in the harness. We replaced the wire in the harness with a thicker grade wire and I've never had a problem since. We just checked the continuity of all the wires in that part of the harness that leads to the boot lock. Identified the faulty wire replaced it and put the harness back. From memory when we fixed the boot wire my camera also started working.

Good luck

 

Thanks for the reply Britcars. I was debating going that route by fixing the single wire within the harness (one by the right trunk hinge); however, I decide it was best to get a new harness to rectify the problem with the reverse camera aswell.

I found some used ones on ebay around the $100 CAD mark, and decided to buy it new from my local Jaguar dealership for $140.

I'll be installing it tomorrow, fingers crossed.

PS, do I need to disconnect the battery before attempting remove older wire/installing the new one?

 

Hey Joebit, thanks a bunch for the reply. Instead of testing individual wires, I'm better of changing the entire harness. Come with two connectors on each end and what appears to be a fiberoptic wire only extending from one end.

Did you disconnect the main battery before attempting the fix?

 

No need to disconnect battery as the harness plugs in and out of sockets/connectors. But given you have a broken wire that could make contact with the bodywork by mistake, I would suggest you do disconnect it for peace of mind
Easy to do. You will need to reset clock and the window up/down limits when you reconnect it

 

Update

I changed the C2Z19978 (wiring harness) with no results. I do not have a wire tester to check which wire is malfunctioning though as far as I can tell, all the wires have current in them and it's the latch mechanism/motor/sensor within that is malfuctioning. Please review the two video clips below to get a better understanding of what I'm on about.

Trunk latch had previously malfunctioned aswell (it was not latching as seen in the video, but the soft close function was not reopening the trunk automatically and all trunk release methods were working as intended) and was changed under CPO warranty less than 8 months ago.

Trunk Lid
https://www.youtube.com/watch?v=z_MVHv1XNMQ&feature=youtu.be

Trunk Latch
https://www.youtube.com/watch?v=5qqS...ature=youtu.be

I opened the trunk using the key, once the trunk was open I changed the wire and since then the trunk refuses to close (Latch). I then disconnected a wire connector that connect into the latch itself (top part of the latch in the lid), and then reconnected it. Locked and unlocked the car, removed the key blade and the trunk finally closed.

Any advice would be appreciated, I'm leaning towards the latch being bad and I'm hoping I can get it replaced since 8 months is too short of a time for a brand new OEM part replaced by Jaguar to break.

 

I tried closing the trunk after disconnecting the wire connector connected to the latch mechanism (Not the main wire loom in the rubber housing towards the left gas strut), I assumed that would disable the soft close function thus allowing the trunk to latch and not bounce back up; however, the trunk latch completely stops working at that point. Once the wire was diconnected, the trunk would not even partially latch to the bottom latch by the bumper which leads me to believe that the latching mechanism needs current to initiate the latch in it's closed (hooked) position.

 

Looking into getting a new latch and motor from the dealer this coming week. I'm no mechanic, but I know the issue is not directly related to any wiring in the boot since the backup camera, fog lights and license plate illumination lamps are working absent issue. The motor is getting current hence why it is "functioning", though not as it should. No idea why its opening back up - perhaps there is some physical/mechanical interference causing it to reopen, but none that I can see.


Happy to hear thoughts as I'm aiming all over the place.

 

Bought a used trunk latch and motor off of ebay. Has anyone replaced theirs and can give me a few tips (I.e disconnect batter or the main wiring loom to prevent possibly electrical damage)?

Could there be more to it based on the fact that none of the three sources (interior trunk release, keyfob trunk release or the rubber button under the chrome piece) are releasing the trunk? No sound from the motor upon pressing any of the three buttons/switches.

 

The likely causes are:
1) a fault in trunk latch solenoid that prevents it from opening
2) a fault in the trunk latch sensor, so it thinks its already open
3) a fault in the wiring so no signal is reaching the latch
4) bad contact between the latch and the wiring harness

Put a meter on the latch supply and see if anything happens when you press the release button. if there's no signal then its in the wiring. From memory none of the devices in the trunk lid share common connectors anymore, they have their own independent ground and signal lines, so even tho all the other things might be working it doesn't mean that there isn't a wiring fault.

Since you've got yourself a replacement, the easiest way to test this is to unplug the latch and plug it into your replacement one and press the button on the truck, it should make a click noise. If its works then swap them over, they're only held on by a few bolts. but make sure its aligned properly otherwise it won't strike in the right place on the lower lip.

 

Hey Fivel, thanks for the response. I will be testing the new latch tomorrow and report back.

PS, did you get a chance to see the two video clips I linked? They're a recording of the trunk latch in action.

 

Sorry, I didn't notice the videos but it looks like the latch actuator works as it seems to want to pull down but then releases. That could be a sensor fault, or the wiring for the sensor, as the car doesn't seem to know that the lid is closed so its opening the latch again. Below is a wiring diagram for the 2012+ models. The latch has two sensors. I'm assuming that at least one of those signals is working because the car sends the correct signal from the rear junction box (RJB) to shut the latch when you shoved your screwdriver in it. I don't know how the car treats the two ajar signals, or why they go to two different places, or what happens when they are say conflicting things - I'm assuming the connection to the RJB directly controls the actuator and the CJB is used for the anti-theft module, central locking, the dash "door open" warning, the boot open switch, key fobs etc.

Some other things it might be:
1) its not mating with the striker plate on the chassis properly. You can check by dropping the back seats and watch it from inside when it tries to shut, but you might need to remove the boot trim to see it correctly - this is a common problem on Audi's with soft close tailgates, you have to fiddle with the striker to get it exactly in the the right spot, given that you say your latch had been changed previously its possible that its not in exactly the same position as the old one and not quite in the right position. If your electrical checks seem to suggest that its working properly then I'd start here.
2) the car thinks there is a key in the boot so it won't let you shut it.
3) the boot release switch is stuck on and constantly sending an "open boot" request to the CJB (via the instrument cluster).
4) I don't have the soft close feature on mine so I'm not sure how the car responds to a fault in the soft close motor, it could be that its returning a random position that is confusing the RJB. However on other makes this sensor is only really used to control the motor position and tell it when to stop the motor rather than to control the latch (so that when it fails you can still close the boot lid manually) so this seems unlikely.