Does anyone know if the dash trunk switch from a pre 2014 XJ can be reprogrammed to not only open but to close the trunk?

 

I second the motion. Having to get out of the car to hit the trunk close button after opening it from inside seems crazy.

 

The trunk lid is controlled by its own module (PLM), which is located to the right of the rear wall (see connector C4PL20A/C4PL20B attached). It controls the movement, but for security the power to the latch is controlled by the central junction box (JNC - the one behind the rear seat back) in combination with the keyless vehicle module (KVM) which ensures that a valid smart key is within (or with range of) the vehicle. That stops someone smashing a window and then opening the trunk even if you power the motor.

1) C4PL20B-23, 0.35mm blue with orange stripe is connected to the internal trunk lid switch which, when connected to ground, signals to the module to initiate the trunk lid close.

2) The signal to open the trunk lid from the external trunk release button on the rear bumper cover connects C3B01A-15, 0.5mm brown, at the JNC to ground to initiate the smart key check.

3) The signal to open the trunk lid from the button on the dash (auxiliary lighting switch) connects the C3BP01H-14, 0.35mm white, at the JNC to ground to initiate the smart key check.

With keyless entry, operating the external button will initiate a comms between the key and the KVM via a local antenna mounted next to the switch (and in each door handle). It is possible that the signal from (2) above would expect a smart key within range of the rear button in and not use the internall antenna, so it may not work. (Just a guess there.) Therefore using (3) to trigger the open seems a better idea as you would already have the key in range of the cabin antenna in the centre console.

Schematics are attached.

Some testing will be needed to work out the best way to achieve this as it is not clear from the electrical schematic whether the latch provides feedback to start the motor for the opening action, or whether a MS CAN network message is required.

The "open" command looks to be managed by the JNC which talks to the KVM as needed before releasing the latch, and the latch ajar switch is then used to signal to the PLM to start the motor that lifts the trunk lid.

An initial thought is we could add a latching relay in between the existing auxiliary lighting switch and the junction box to toggle it over but managing the state becomes important then. Maybe a better approach would be to use the trunk ajar micro switch input to the JNC to toggle the switch from open to close signal using a normal relay. That would require splicing in at the JNC and the boot lid to cabin harness, so keeps the wiring mods to just one area.

 

As usual xdave is the man!! Thank you. xdave, are the schematics different for 2014 forward as that funtion is now integrated into all Jaguars including the XJ. So I guess my question is can an SDD hack add this feature to pre 2014 XJs? Also I don't see the dash switch in the schematic.

 

The dash switch is the auxiliary lighting switching (bottom right of the schematic).

I have had a look at the current XJ user manual on the Jaguar web site and I can't see any mention of being able to close the trunk from the cabin.

I've had a quick look at some XE schematics to see if the setup looks the same, but it isn't. The security system is involved in the opening of the trunk lid and that is handled between the JNC (highly vehicle specific) and the KVM (a shared system).

I have had a flick through the CCF for my car and couldn't see any setting that would enable this on the earlier ones. (Highly unlikely because they would have offered it as standard, as they do on their more recent models.) I have attached an anonymized copy to this thread that you can look through to see if you can spot anything? Page 13, Tailgate/trunk function, Remote luggage compartment lid release is only Tailgate (as set) or Not Fitted. The only other settings I can find are to include or exclude the trunk from the valet mode locking.

 

I'v attached a partial list of the current XJ from the Jaguar site and under Standard Features "Safety and security it does show open close feature. I know alot of modules changed in 2013 and again in 2016, but I am thinking that this feature was added in 2014.

 

The X351 has technically always had power trunk open and close with customizable height adjustment - it just uses two different buttons rather than one.

I'm at my dealer on 16th so will check a current model to compare operation.

 

Hi xdave, any update now that you have been to your dealer?

 

How can you dump the readable CCF? I assume using SDD but am unsure where to find the ability to dump/make a pdf file.

 

The service manager did not know the answer, but we looked at the 2016 XJ SWB in the showroom and it behaved the same as my 2010. The button on the instrument panel would open but not close the trunk.

I made the PDF myself by formatting the info in Microsoft Word. IIRC once you start a session in SDD you go into the session settings and there is a page with all of the session info show, including the full CCF info. You then copy/paste that and format how you want. I've done it for each of my cars so I have a handy reference.