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No such panel exists on X351. No mechanical lock anywhere than drivers door.
The factory X351 Service and Repair manual give two options after accessing inside if the cabin with emergency key thru drivers door:
- Option one: Open hood and add power to the power point inside of engine bay fusebox and the press Open Boot button. Nothing else, don´t turn ignition On !! (also descripted on Owners handbook)
- Option two: Remove back seat and rest. There are an plug/wire to power only the boot lock solenoid. This is for the cases that battery are removed, trunk closed and battery Plus terminal shorts to chassis. -> vehcile circuit unusable.
XF is totally different chassis and its more worth to write tricks and hints on XF forum instead of XJ forum where they are unusable.
Are you able to post a photo of the fuse box area behind your rear seats so we can look to see if the connector is tucked away? The instruction photo at the top of this thread is being offered up in the 2011 XJ workshop manual so it should be there... somewhere.
The diagram showing the engine compartment location is below. This is probably what you have already tried though. I note you mention the glove box won't open. There are two logical causes for this:
1) the battery is so flat that applying 12VDC to the engine compartment stud is not enough to bring the voltage up for the CJB and KVM (keyless vehicle module) to function, in which case leaving it connected to a charger for a few hours may help, or
2) the battery still has charge but the CJB (fuse box behind the seats) has crashed, in which case removing the connectors to reboot it may help.
I assume I could attach a piece of wire to the threaded stud shown here with another connected to one connected to the chassis, run the two wires down so they're accessible beneath the front of the car, and use them for either this very "emergency", or simply for charging the battery during a couple of weeks when I'm away on holiday? I'm thinking the wires would actually be a modified CTEK extension lead fitted with an inline 10A fuse near the fuse box end for safety.
I've studied the electrical diagrams (I'm a retired electronic engineer) and it looks like this should work (going to earth also presumably means I'll be charging on the "correct" side of the battery monitoring system too).
Any thoughts? Do you know if anyone else has tried this? I'm absolutely paranoid that one day I won't be able to get into the car and its boot (quite what Jaguar thought to do this I don't know, my 2008 XK has got an emergency boot unlock hidden behind the rear number plate).
You have a key to open the drivers door. Do you know it's hidden in the FOB?
Then you can pop the hood because it's not electric. Now you have access to the power points to open the trunk.
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Yes, I realise all that but I was after some way to charge the car without having to drag a cable all the way to the boot (I park up against my garage door and a mains socket behind it).
Being able to use the same cable to open the boot if the battery was flat is simply a secondary benefit.
Yes, I realise all that but I was after some way to charge the car without having to drag a cable all the way to the boot (I park up against my garage door and a mains socket behind it).
Yes, you can use the posts under the hood for a trickle charger or jump starting.
If you have 2010-2013 vehicle: NO. Do not turn ignition On or start.
(check post #46 on this thread about warning label)
Yes: You can trickle charge battery thru posts under hood.
Yes, you can use the posts under the hood for a trickle charger or jump starting.
Many thanks. I thought that was the case but wanted reassurance. Don't worry, it will be for trickle (CTEK) charging or supplying 12v as described in the manual only!
What happened: the last time I closed the trunk, I noticed the escape handle wasn't in its proper position, but hanging from the trunk instead. Next time I tried to open the trunk, it were stuck: I couldn't hear the lock releasing, but the motor was actually trying to open the trunk, slightly moving it on the right side.
I first followed the instructions to try to trigger the lock with the connector situated behind the rear seats, to no avail.
So I had to find a way to manually pull the escape handle inside the trunk. Here are a few photos and explanations.
First of, release the back seat base using the 4 latches (beware they are fragile, broke one of them).
Unlock the base by pulling it up and forward, disconnect electric connectors on both sides, and remove from car.
Then you can see 2 white straps hanging from behind the seats back.
You have to pull those downwards, quite hard, so as to unlatch the seat and then tilt forward.
Once tilted you can pull up the seat so as to disengage the 4 axis at the bottom, and get the seat out.
Now you have access to the (black or white) cable cover that closes the hole allowing the cables to pass into the trunk.
First unclip the flat cover on top, so you can access to the clips that maintain the cover attached to the metallic body.
You can then bend the cover, and you will see the trunk covering beneath.
Now you will have to cut it with a cutter to make a hole, and you will have finally access to the trunk.
Using a metallic rod with a hook you will then be able to catch the escape handle hanging from the trunk lid, and pull it.
Hooray! the trunk opens!
After that the car would beep whenever I tried to close the lid, I had to start the engine, and then everything was back to normal.
I have no idea what caused the problem however.
Good luck.
Thanks a ton for these posts and info. In my infinite stupidity, I disconnected the negative terminal on the battery while getting ready to work on the HPFP replacement and then closed the trunk. I am going to try the method mentioned in the initial post above (feeding 12V directly to the connector) to see if I can get it unlatched before trying the mechanical way that you mentioned. The bottom part of the rear seats has come off easily, but the seat backs will not come off / hinge forward even with pulling the straps that stick out the bottom. I am going to try to wiggle them to see if it helps, but otherwise any pointers would be greatly appreciated .. once you pull the straps, do you move the seat back "up and forward" or "push it down and forward" to get it to come off? Will try both .....
Now the kerfuffle in the HPFP pump replacement, I'll post it on that relevant thread. Thanks in advance for all of y'all's help.....
A quick update on my rear seat back situation - no matter how much I tried with pulling the straps to release the seat back, it would not come off of the brackets. I resorted to unbolting the seat back at the bottom 2 nuts (2 on each site, the ones that hold the seat belt parts in place), freeing the seat back at the bottom and then random wiggling, gentle twisting the bottom up with random pulling on the straps and a lot of cussing to finally release the seat back from the driver's side bracket, then pulling it gently to examine the mechanism on the other side and inserting a wrench over the metal arm that sits in the bracket on the passenger side and pushing it down while pulling the seat bottom down and out to finally release it. Phew ---- so the seat back is out.
Located the direct 12V feed to the trunk latch and unclipped it. There was a single metal pin on the male side of that connector. Tried to pass a 12V feed through the NOCO jump starter that I have but the NOCO did not deliver the current, it was giving me an error code. Then I used jump starter cables from my other car battery with the car running and connected the negative to the door handle latch bracket for grounding and the positive to the said pin inside the connector --- lo and behold, it worked and the latch clicked open. So now the trunk situation is solved and the battery reconnected. I can now at least operate the release on the parking brake and use the emergency neural apparatus in the central storage box to get it towed to the dealer. Cannot start it since one of the hpfp pumps is halfway disconnected and the engine oil is drained halfway through....
Hi all, I'm new here and could definitely use some advice. My 2011 XJL is completely dead. With that, we can't access the battery in the truck, so we tried to jump it accessing the fuse box under the hood. We got nothing - no lights, no action at all. I can't open the glove box to get to my manual. Is there any other way to gain access to the battery? What's my next step? Thanks in advance! Juliet Marie
connect a jump to the front electrical box and it the same time use your key fob to open trunk or have a second person pressing the trunk button .. I just had to do the same thing after my car sat for a few months while in the hospital and didn’t connect it to a tender and it was completely dead .. it didn’t work at first but reconnected the jumper cables to the positive connector and the bolt on the shock and it finally worked … I bought the best battery for my model at Walmart for 240$ and everything worked after the car runs through a cycle reconnecting the car to its computer the only thing that wasn’t working was the emergency break but you can follow the procedure to fix that there are videos on YouTube .. Good luck
Bought an XJ a few weeks ago, disconnected the battery and then closed boot lid the next day, ironically so I could charge it. I found this thread while searching.
A 12V battery on jumper cables to the posts under the bonnet, as described in the manual, allowed the boot lid to be opened on the key fob. This is exactly as others have said here and did not require taking the car apart. My battery was fully disconnected. Being the sort to want to understand how things work, I can't see why that would work for me (and others) while not working for some. These are mass produced cars assembled from the same parts - they are not hand fitted machines made of 75% whatever was to hand.
Most 12v battery chargers aren't going to supply 12v to the car at any one instant. This just denotes are suitable for use on 12v (i.e. not 6v or 24v) automotive circuits. They will supply enough charge to fully recharge your car's 12v battery over time, which is not the same thing. The exception to this is chargers that have a supply mode (which is actually more like 13.6v) but ignore that. If you tried a charger and it didn't work, this is why.
As for if/why you shouldn't jump start from the under-bonnet posts, just look at the positive tab the manual states to connect to. When you crank an engine, you're sending however many hundred amps (usually 700+) down the wires, which is why the jumper cables are so thick. A little tab on an M6 stud is not going to handle that. Ever. Please, for the love of your car, do not try to jump start it like this. It's only for allowing access to the boot, which must be drawing at most a couple of amps.
I hope some of this helps people who find this thread from ripping the rear seats of their car out, when it can be solved in minutes with the right equipment.
Last edited by FourLitres; Apr 1, 2026 at 04:52 PM.
@FourLitres Your 2012 XJ came from the factory with a Battery Monitoring System module attached to the negative (black) terminal of your battery. If a battery charger or battery maintainer was ever directly attached to that negative battery terminal, your BMS Module could be damaged. Also, damage to that BMS Module may have occured if jumper cables were ever attached to that negative battery terminal.
A bad BMS Module could be the cause of your problems. Google how to reset it. The link I found didn't work when I copied and pasted it into this post.
5.0L owners should always use a chassis ground. Never attach anything to the negative battery terminal. Doing so could brick your BMS module.
Note that most auto technicians are clueless about the BMS Module, unless they're Jaguar -trained. That module causes the alternator to behave kinda funky, which can lead a technician to believe that the alternator is defective when it isn't.
Stuart
Last edited by Stuart S; Apr 2, 2026 at 12:50 PM.
Reason: Correction re: link
@FourLitres Your 2012 XJ came from the factory with a Battery Monitoring System module attached to the negative (black) terminal of your battery. If a battery charger or battery maintainer was ever directly attached to that negative battery terminal, your BMS Module could be damaged. Also, damage to that BMS Module may have occured if jumper cables were ever attached to that negative battery terminal.
A bad BMS Module could be the cause of your problems. Google how to reset it. The link I found didn't work when I copied and pasted it into this post.
5.0L owners should always use a chassis ground. Never attach anything to the negative battery terminal. Doing so could brick your BMS module.
Note that most auto technicians are clueless about the BMS Module, unless they're Jaguar -trained. That module causes the alternator to behave kinda funky, which can lead a technician to believe that the alternator is defective when it isn't.
Stuart
I was lucky enough to not damage anything when I attach the battery maintainer.. everything worked out but after I did what I thought was normal (dumb on my part) I found out the right way . Since then I’ve done a lot of reading up on my X351 from maintenance to sagging headliner , then my next project paint correction to make her shine like it’s 2013 again .. thanks for your response and appreciate knowledge from forum members
Thanks Again
Is there any other way to gain access to the battery? What's my next step? Thanks in advance! Juliet Marie
