On My 2011 XKR Both my license plate lights have no power, all my other lights work fine I pulled the bulbs and no power, thought just a bulb issue, I have owner's manual and it does not show a fuse. Does anyone know what fuse or have run into this problem before?

 

The Auxiliary junction box, which is located in rear seat, center seat back. I have seen some issues with this junction box for various reasons ( fuel pump issues, hazard light issues, etc. ).










Description: Junction box-Auxiliary CONNECTOR HOUSING NOT SERVICEABLE Location: Behind rear seat backrest Qualifier:
















Pin 13 on Connector CA023 is the wire that goes to License Plate Lamps - Should be a Blue wire. If you have power at the junction box/fuse box, then your problem lies between junction box and license plate lamps.


If the issue is inside the junction box, you may be able to take out, disassemble it ( make sure you mark all the fuses and relays before you do this ) you might be able to find fault inside and have it repaired.

 

pulled backrest and found no CA023 connector but a C11 connector that had the same color wore leading out, turned on headlights and I have 12 volts, but at the license lights 0 volts, definitely a wire in the hatchback is the problem....THX JBzXJ40 for your help.

pic of rear seat fuse panel

 

I'm not sure it's wiring. I had the exact same issue, also checked my bulbs, which were fine. I brought my car into my dealer, who's great, for servicing and my mechanic there (I have the same guy every time) told me that he'd seen it before-- it's a computer module or logic board or the like. They did a "reflash" and it fixed the problem. He said if it hadn't worked, the only other fix is to replace the computer module. And yeah, they wold have replaced the unit that's between the rear seats.

 

The fuse boxes these days aren't just fuse boxes anymore - they double as control modules as well, not interchangeable either ( security purposes ). Yes sometimes a software update can fix things, even a battery hard reset.


There have been known issues in wiring in the boot/trunk lids due to the open and close motions. Being an XK, the hinge area where the wiring will go through isn't on the same angle as an XJ, but still worth checking into.


You're very welcome californiarobb - I hope you find the culprit soon.

 

I had the same problem on my 2011 XKR. Dealer resolved the issue by "updating flash drive". He said there are no fuses for the tag lights. Don't know if that's all years or not.

 

The earlier XK's ( X100 ) were controlled through Security Lock Module, and you would get a bulb failure message if bulb was burned out. These had issues with bulb housing which was detachable from tail lamp housing ( ground issue ).


XK150's are controlled through Auxiliary Junction box, which also acts as a control module. I haven't seen the issue as described in this thread, but at least its an easy fix. I have seen some wiring issues with rear lighting on XK150's, but nothing major.

 

Take the tag lamp bulbs out. Now check for power at the Aux junction box.
If you have power now, disconnect the battery , both terminals, and hold the connectors together for about 20 Sec.
Hook up the Pos, then hook up the Neg.
Replace the tag lamp bulbs.
Turn on the lights and they should work.
I've done it on three cars so far.
Hope it works for you.

 

I have commented on this before. There are no fuses in the exterior running lights (including LP lights). They use FETs (Field Effect Transistors) that will protect wiring by going open when they detect very low resistance (shorts). They can be fooled by heat or bulbs shorting internally, and sometimes moisture. Typically, just disconnecting battery will reset the junction box and FET crowbar condition. The previous posting with a reset procedure was very good. I have noticed some dampness creeping in at license Plate fixture and that probably was root cause.

 

I had taken it to the local Dealership and it turned out to be the Auxiliary Junction Box, $3800 later my license plate lights work and I had noticed my rear fog lights were acting up... but all is well now.

 

Thanks for the tip! I just failed my state inspection this morning, found your solution and now I have my state inspection successfully completed.
It took me a little while to figure out what you meant by disconnecting both battery terminals, since there is only one battery feed in. I disconnected this one, shorted the junction box terminal (NOT the connector from the battery!) to ground for 20 sec and reconnected the battery cable to the junction box.
Now the lamps work fine.

 

Hi DavidBlackLaw, could you please describe what wires you were talking about more specifically? The same thing happened to me today when I failed my state inspection.

Steve

 

Hi, in reply to your question:
- disconnect the power in to the rear junction box
- Tape up the power cable you just disconnected (just to ensure you don't accidentally touch something with it)
- With a separate wire, connect one end to ground (e.g. a convenient bolt) and the other to the terminal on the junction box that you just removed the power cable from. Hold this connection for 20sec or so. What you are doing here is ensuring that everything in the junction box is fully discharged.

 

Did you also remove the light bulbs too as was suggested in the earlier post?

Thanks

Steve

 

 

Thank you all.

Took of the battery cables, touched them together and I am back in operation. The dealership wanted $194 to run a diagnostic and $200 to reprogram. Ugh!

Have any of you had to do it again once you fixed the problem?

Steve

 

Yes, just remove both cables from Battery and touch them together.
No need to remove the positive feed to the module.
you don't have to remove the bulbs, that is part of the diagnostic procedure to see if the module has power when there is no complete circuit.

 

Hi everyone,

I followed the procedure well enough to get past my state inspection but later the same day the license plate lights went out again. I once again disconnected the battery cables held them together and put back on and viola I was back in business. For less than a day. They lights are dead again. Has anyone else had this problem?

Thank you.

 

My plate lights do not work either on my 2011 XKR. Dealer says it is a module. $1000.00 !!!!!! I am in the process of getting it fixed. RIDICULOUS !