Have a 2001 XJ8. When driving today the "Check rear lights" message began coming on when braking. I parked and turned off the car and both brake lights remained on. I locked the doors and after a couple of seconds the alarm went off (odd).

I got back in, took around for a few blocks, got out and noticed that only the passenger side brake light stayed on when I parked and the ignition was off.

Since this initial incident a few hours ago, I've had problems opening the trunk with both the key fob and front/driver's side trunk button.

Is this probably a security module problem? Completely replace it? How much on average for a used security module?

 

Before a security module . . . the micro switch at the trunk latch is a common problem. Also, on the XK at least, there is a wiring harness at the flex point of the trunk hinge that reliably breaks wires inside the harness.

Security module after everything else is eliminated.

 

Right side trunk hinge. Under plastic cover, check the bundle of wires inside of tape. Mine had broken and been fixed and broke again, leaving the car in valet mode, which meant the trunk switch on dash would not work as well as problems with trunk light, license plate lights, brake lights ...

 

+1 on the cabin to boot loom. My symptoms where a boot switch that didn't work and cabin switch also none op. I found one black earth wire split, I soldered it and shrink tubed it then taped the loom back up with a more supportive tape. The wires might last that bit longer before another breaks. If you don't find a break (highly unlikely) you might want to have a look at the electrical guide and what colours control the items giving you the weirdness.

 

Excellent advice (I hope). I'm going to check on the trunk tonight. Only problem right now is that I can't get it open. Key fob won't work altogether now (was working before), and the trunk button left of the steering wheel also won't work. I tried manually opening it using the key to no avail as well.

Any suggestions on getting it open?

 

First, I would try to spray a little lubricant into the key hole and 'jiggle' the key. That is a direct link, not an electric one, so it should open the trunk.

If that doesn't work read through this link:

Any possible chance to get the trunk open? - Jaguar Forums - Jaguar Enthusiasts Forum

 

hey abittaman,

i reccommend you get this thing to your old man on his day off so he can give you a hand. key is do it at his convience and bring him a cold beer.

just my $0.02 worth

 

My old man does enough stuff for my car already. I owe him a couple beers as it is.

Figured out what it is. Got my car cleaned the other day and some water leaked into the bottom trunk. The security/locking module was wet and corroded. The little I know about electronics tells me mixing circuit panels and water ain't too good. Dried and cleaned off to salvage it but same problems persist.

New module and I should be good. Thanks for the help.

 

My specific parts number is LNG2600HB.
Serial number B008432.

I can't find any used parts on line for this specific number. I did find security modules with the following: LNC2600HE, LNC2600HD, LNC2600HB.

Would these work?

 

If you are seeing corrosion after, what you describe as only a few days, you may have had a long time leak.

Try spraying the control module well with WD40. The WD stands for 'water displacing'. May, or may not work but it is a low cost effort.

You will also probably have to deal with the VCATS (/xxx ) extension of the part number. Here is a Jaguar TSB addressing swapping modules but it doesn't specifically address your part number question.