Hi guys, I need some suggestions. 2 day ago I got the message check rear lights. The right side brake light was out so I replaced the bulb and still it's not working. I realized the bulb Sylvania says fits my car was wrong and replaced it with the correct Phillips bulb but I am still getting the message and the brake light still will not work. I removed the taillight socket housing and cleaned all the contacts checks to see if there are any shorts or dead links between the plug and socket everything seems to be correct. Could it be a fuse? I know Jag has a fuse for everything but do they have one for each individual light? I am going to test the wiring with a volt meter at the socket later as soon as I can find someone to step on the brake while I work in the trunk. I have had three Jags never came across this issue usually I replace the bulb problem solved. I am going to try and find the wiring diagram in my Jag manual today when I get a chance. If anyone has a clue let me know if it can save me time and aggravation it would be greatly appreciated.

 

Hi John,
Everything you require is in the trunk. With someone's help, check the output at the security and locking control module at pin BT1-3, orange/yellow wire. This goes to the right hand brake light. If you have a supply there then check the connector at the brake light, same coloured wire.
If you have supply at the brake light then try running a separate ground to see if that works.
An alternative is to run a wire from the left hand side live to see if it powers up then.

Forgot to mention, there is no separate fuse.

 

I'd check the wiring on the right side hinge area. Look for a broken wire.

 

Thanks guys, I checked the whole tail light assembly for continuity and it all seems to check out tomorrow I'll have some one step on the brakes and see what I am getting out of the plug and work my way back. It's possible something in my trunk banged against something I had a bunch of new tools I bought bouncing around back there the day this happened. I always hated auto electric work I might have excelled in class etc but still hate it.

 

You can use a broom handle, shotgun or a long 2x4 to hold the brake pedal down. Just move the seat back and forth.

 

I use a small floor jack handle. Put the metal end on the pedal then put the rubber grip end on the front edge of the seat. Power the seat forward to depress the pedal.

 

My experience is that:
- If the message comes and goes irregular, it is mostly related to a battery problem (lower voltage), it is about the first indication of it,
- If the message is always there, it is most likely a bulb, an contact, or worse, a problem with the module.

All is easily reachable, clean up all contacts, be sure you check ALL bulbs (I had twice a dual filament burnt into each other), and bend the contact plates so all is tight. Also check the contacts for the plug.

The wires in the hinge are not related to the rear light units, only to the license plate and trunk lighting.

However, the wires to the light units are kind of unprotected, laying under the trunk lining, so you might check those too.

 

I used to have an old adjustable aluminum cane I used to use to hold a brake pedal down when I did work on cars it's no where to be found here at home it might be in my truck I store at a friends. The problems has to be a wire or the module. I am going to trace the wires later and see if any are broken. I did clean and tighten all the sockets and plugs. I checked the taillight socket housing with an OHM meter and I am getting good readings every thing is OK there. I started checking the power at the plug but got sidetracked and forgot to go back out and finish. It got dark now I'll have to wait.

 

You have a bad SLCM. Lots of threads. The Robert DIY Youtube is NOT the way to go. Find a SLCM that matches your number on eBay or send yours off to Idaho and get it rebuilt. Do a Search.

 

I am afraid it might be a bad module wires seem to be fine all the connections look good everything seems to be OK. I have to check the numbers to see if I can find one. Pain in the *** IMO what can't Jags be simple. LOL

 

Aren't the left and right side brake lights wired in a parallel switch? Does the connector have any voltage between ground and stop light line when the brake pedal is depressed?

edit: nope, each side is separate. Guess it has to be for bulb monitoring purposes. OY and U are the two color codes for the brake stop lights, so solid blue and orange with yellow tracer.

 

Thanks guys, It's been too cold the last few days to screw around with it. I have a few more tests I want to do before I take it to my mechanic to check it in case I missed something. Getting a new module or having it refurbished is no big deal I just want to make sure that is the problem before I shell out the dough. I used to work in the electronics field back in the 80s if I can find one from one of my used part sources if I can get a working one I might tear the old one apart and see if I can fix it. Worse case I can't and I toss it!

 

There are many threads that discuss fixing the unit (as well as what to watch for when buying one of eBay). One, from Bob Goff (Motorcarman) discussed repairs with others chiming in on how to take the box apart to get at the right posts. Worth both a search herein as well as Google.

 

What search key words should I use? I did a few searches and didn't find exactly what I was looking for that is why I started this. I still haven't had the time to play with it further. Just too busy. I still can't figure what in the hell Jag was thinking running the brake lights thru the security system. I thought it was to signal the alarm had been set but the turn signals flash not the brake lights. I hit the panic button and set off the alarm and the brake lights still don't flash when the alarm goes off. Looks like I have some time tomorrow we decided to stay late tonight and prep for the weekend and it's going to be a nice day. Hopefully I will make some progress other wise it's off to the shop.

 

Brake lights; security and locking; SLCM repair; SLCM problems;

 

Well, Brought the car to the mechanic to replace the alternator he said it will need a new SLCM. He jumped the left to the right so I can have both brake lights for now but I am having a hard time trying to find a used SLCM or even someone who can rebuild it. Problem is I need the car I can't leave it sit while I wait for a part. Aside from Ebay is there any place else to find these? Of course now both my Tail lights are gone the only brake light I have now is the third eye in the back window! I am going to pulled the SLCM out this week and get a good look at it and the wires do some testing etc but I am pretty sure I have to just get it repaired or replaced. I'm getting a little sick of this car my last one was no where near the problems the later ones has had.

 

The problem with 'jumping' the brake lights together (joining the left to right) is that ALL the power to light BOTH bulbs is drawing too much current from the semiconductor designed to light ONE BULB!!!!!!!!!!

The remaining semiconductor will have a SHORT LIFE.

The inop brake light SHOULD have been connected to the RELAY for the HMSL.

bob

 

Keep trying eBay. I wish you had gotten back to us sooner: I just tossed a bad one that could have been sent to Idaho for a repair.

Make sure you have the right number.

 

Called my mechanic he is looking for a used one, He has the computer to reprogram it and I am going to have him save the old one so I can send it out for repair! It's always good to have an extra in case the used one ***** the bed. Right now I am charging my battery I forgot to shut the lights off the other day while trying to see if the tail lights were actually working or not. I am use to leaving the lights in auto mode so when the key os off so are the lights. My fault. Just waiting to hear from my mechanic. Maybe I'll try repairing the old one myself I used to do electronic repair ages ago.

 

The only thing that needs to be configured after installation is the keyfob transmitters!!

bob