i just bought my first jaguar its a 1999 vander plaus 4.0 xj8 and im haveing an issue with the brake lights. it seems they were working yesterday. and now their not. i replaced all the bulbs and all the other lights work ok.even the high mounted light works.and i get a rear brake bulb failer reading..i changed the bulbs again.and the code went away.as soon as i hit the brakes the code came back,,and now no brake lights, but all other lights includeing the high brake lights work ok. checked all the fuses and all are ok.even replaced the brake relay in the trunk.and still nothing..any ideas what it could be?(ground,fuse,another relay)????please help.... well after checking around it was the slm thing. s

 

Do a search of the forum -- all the lights are controlled from module in the trunk -- you will need to check the outputs and see if it is a wiring problem. The module is known to fail -- some have reported fixing it ..........

Unfortunately -- the part is $$ and you must get the correct version of the module -- so you can't just swap it out from another car without making sure it is the correct one.

 

The SLCM is not a plug and play as yeldogt stated.

Here is some additional info.

bob gauff

 

Motorman - Thanks for the TSB. That is the one I remember reading.

I was not trying to indicate that they were "plug and play" as I don't know what is required in the programing of the system - I was only aware that you must source a very specific module if you have any hope of getting one cheaper than the dealer.

I just did not want the OP to go on ebay and order a replacement thinking it would work.


I did hear of one individual sourcing a module and swapping out the SSR's on the board -- I believe it has three -- each side and the center ........ I don't remember the outcome?


Like I indicated the OP is going to have to do some searching and diagnostic
work

 

sorry yeldogt that is not what I meant, I should have swapped the words to read..

As yeldogt stated, the SLCM is not a plug and play.

bob gauff

 

it was the slcm moduel..will be some time befor i can buy a new one so for now i had to bypass the slcm to get brake lights.till g can rake up 850.00 to buy a new one..but it works so thanks for all the help and post from other with wireing diag. and all help so much with tracking down the wires.. i really appreaciate it..lue

--i cut the blue and white wire along with the red and black wire from the slcm unit and tied it into the purple and blue wire from the brake light relay.in the trunk compartment since the high brake light in the back window worked with the brake peddle depressed.the current went right to the brake lights. i still have the system check reading rear light error but i just turn it over to my miles.so no biggy..it works great and all the other lights and turn signals and rear fogs and everyting else works great..--

 

So how did you bypass it? Might be helpful to others in the future.

 

--i cut the blue and white wire along with the red and black wire from the slcm unit and tied it into the purple and blue and green and black wire from the brake light relay.in the trunk compartment since the high brake light in the back window worked with the brake peddle depressed.the current went right to the brake lights. i still have the system check reading rear light error but i just turn it over to my miles.so no biggy..it works great and all the other lights and turn signals and rear fogs and everyting else works great..-i also put a fuseable link inbetwen each one of the connections just to be safe-i used some of the diagrams i found on the site to track down the correct wires (thanks to all who posted diagrams)your a life saver...and thanks to all the people who replied to the post..now i just have to fix my radio its acting up.and doing wierd stuff..i also added pics of my jag in my garage here on the forum.hope you all.. like..its my baby.

 

Good news, thanks for your feedback , appreciate that as well

 

Thanks for the reminder. I had forgotten about having that thought when someone else had the same problem.

 

without looking at the diagram -- are you saying you are now powering the lights out of the high mount relay or from the high mount module?

So the rear center has a relay?

I remember someone else on this board using the working brake light output to power both brake lights -- and it eventually overloaded the electronic relay


With the old MB W140's with similar module nightmares -- it was common to use the high mount output and install a relay to power the rear lights.

 

yes the regular brake relay in the trunk i believe its the 3rd one on the fuse box.it is the regular brake relay.and it is getting proper power when the brakes are pressed,so i used it to power the brake lights from the harness area to the bulbs.

 

does anyone have pictures of this??? I am trying to figure this out. There is a harness that plugs into the slcm and t hen one coming out. So what wires in what harness are you doing this with? Does anyone have step by step on this...??? Need brake lights!