I looked through threads and found similarities, but never saw closure t the right brake light outage. I posted to the old thread, but I guess since it is about 3-4 years ago no one has seen my post. I'd really appreciate your input, folks...I'm at a loss.Just started two days ago. One element of the right rear brake light lamp does not light.

On brake pedal press, amber light illuminates and dash displays warning text "CHECK REAR LIGHTS." Release pedal, warning extinguishes.
The only tail light element not coming on properly is the right rear brake light.
Tail light bulbs (half of which is the same bulb as brake lights), flashers, fog light (left only) and left brake light is fine; side marker lights all the way around are good too.

I swapped tail/brake light bulbs from one side to the other, no joy; and both elements in both bulbs work in the left tail/brake socket.
Checked all of the fuses in the rear fuse box. All good.
No apparent corrosion or damage to the lamp sockets, their plastic housing, or the connector and its pins.

I'm baffled. Following this thread is confusing me. What all goes through the security module? What else could/should I check?

 

I'm not saying this is for sure the cure for your problem as there are several possibilities, but I had a similar event with my 2001 VDP, got the "Check Rear Brake Lights" warning, found the rear brake lights and turn signals were not working. Checked all the connections, cleaned all connections, fitted new bulbs, still not working. Checked the battery voltage it was a little low, as I hadn't had the car very long and didn't know the age of the battery, I fitted a new battery. Problem solved.

 

I appreciate the response...and have experienced the anomalies with the warnings when the voltage drops with a flat battery. You were so right, I had to replace the alternator and the battery. Unfortunately, that's not the trouble in this case.

 

It is possible that the fault is in the SLCM. You can trace the link from the stop light to the SLCM on the diagram:



I would open the SLCM and inspect. You may have a burned chip like on this pic:



The 3 chips (amongst which one or two are burnt) are actually electronic (solid state) relays. See whether you have one of the 3 chips (or any other component) burnt, it might be for the right stop light.The three "chips" are most probably all the same and they are BTS409L (as seen on one of them). It's a simple component called "Power Switch". They are easily available on Ebay (BTS409L1 which is the same). Just make sure you get the version in SMD housing, like this one:

 

Okay. I'll take a look....if you can tell me where the SCLM is located? Somewhere in the boot? Must admit to unfamiliarity with the car....

 

Sir, can you tell me where the SLCM is located in the 2001XJ8?

 

Sir, can you tell me where the SLCM is located?

 

Under the boot fuse box - https://www.jaguarforums.com/forum/x...nt-work-88232/

 

Okay, I pulled the SCLM and on visual inspection no apparent problems.
At the connector to the tail light assembly, there is no voltage read at the bulb socket corresponding to the filament nor at the corresponding green wire into the connector. Does that sound right?

There is voltage on the left side at the corresponding blue wire..

So between the schematic and the diagrams in the X308 Wiring Diagrams service manual I checked the PIN for the stop lights; the left stop light Pin 9 (U) has voltage and the right stop light and PIN 3 (OY) has no voltage.
The presumption is that the SCLM is the trouble, even though there is no visual damage on the circuit board?

 

Check whether there is voltage on the SLCM pin to which the green wire connects.

 

The Green wire at the tail light has no voltage at the tail lamp assembly connector.
The Green wire disappears into a bundle routing back under the fender Cover and there is no green wire coming from the 16 pin connector at the SLCM, so I used the wiring diagram to ID which PIN to check.

Looking at the wiring diagram, the stop lamp is BT50-5 is "UW" going to SLCM BT1-3 "UW". I have no idea what UW means, but the wire at that pin position is orange yellow. As a check, I sampled the voltage at pin BT1-9 which should be the left stop lamp; there was voltage there. Deduction leads me to say that corresponding output from the circuit board is not working. Prove me correct? Is it worth replacing the three relays on that board as suggested? Or is there a way to test the output of the relays on the board?

Is UW a color code? I haven't located the key for translating those codes yet. It must be somewhere, yes?

 

UW is Blue/White..

 

I THINK I ANSWERED MY OWN QUESTION ABOUT COMPARABLE SLCM MODULES.
I FOUND THE SAME NUMBER BUT 2x THE COST.
__________________________________________________ __________________________________________________ _______
If I'm not jumping the gun, since I don't have an output at the orange/yellow wires pin 2 or 3, I presume that the SLCM is bad? By the by, Thanks for the wiring color codes, is that in the service manual? If not, I'll print this out to go in my book.

If so what part of the numbers on the module need to be the same to be able to swap modules? There is one on THE BAY at the moment.
Both are X300 SECURITY & LOCKING MODULE 315 MHz but my modules number information is:
LNG2600HB (Image of mine is below)
Visteon 1W9F-15K600-AA

The one on THE BAY is:
LNC2600HE
Visteon P/N 98JP-15K600-BD
(Auction description: 98-03 Jaguar XJ8 Vanden Plas Security Locking Module LNC2600HE)

 

Sorry, I earlier attached diagram for the 1999 (USA) models. This is the the diagram for 2001 which shows somewhat different wire colours and corresponds to what is in your car (full page attached as PDF):



So you have Blue wire for the Left Stop and Orange/Yellow for the Right Stop. Since you don't have voltage on the SLCM pin to which the Orange/Yellow wire connects, it is almost certain the problem is in the SLCM.

An SLCM which has a different part number may not work. Furthermore, the SLCM is programmed and carries a certain VCATS number, not written on the module but only shown on the car's VCATS sticker (see the sticker with VCATS numbers in the trunk, left side, remove the spare wheel and pull a bit the bottom of the left side carpet). The VCATS (programming) number is the the one after the slash, like "/xxx". Even if you get an SLCM with exactly the same part number (LNG2600HB), it may have a different VCATS number and would need re-programming. Finding an SLCM with the same p/n and same VCATS as what you have is almost impossible as sellers of used SLCM-s almost never record their VCATS,

It is therefore much better to first try to repair your SLCM. Try to trace the line on the PC board of your SLCM from the pin BT1-3 (Orange/Yellow) and see to which component on the board it goes. It may be to one of the 3 chips (electronic relays) shown on the pic below. If the line from BT1-3 goes to one of those chips, they are available (see my earlier post) and fairly easy to replace.

 

My R has very ocassional check rear lights message when pressing brake pedal. What I traced from the inside of SLCM is that all of the exterior light switching power is done on the big 5 pin transistors on the side of the pcb. 5pins are there because it does mesure the bulb current too. I re solder all of the 5pin power transistors and the check light didn't come back yet. It has been very ocassional always so... I could't not see any cracks in the led free solders on them but you can't tell if crack isn't obivious.

 

M. Stojanovic - Thank you and thanks to all of you that are helping me out of this jam.

Yes. There is a blue wire (U) to the left stop lamp on both the SLCM and at the tail lamp assembly connector as per the diagram.
Yes. There is an Orange Yellow wire to the right stop lamp at the SLCM, BUT a green to that lamp position in the tail light assembly connector. The new diagram shows OY at the right stop lamp ...am I reading it wrong? I thought I should see green on the diagram?

 

I'll take a look at those 5 connectors, if I can find them.

 

The Right stop lamp should have Orange/Yellow for its stop bulb. The only diagram that shows a Green wire at the right stop lamp is the one for the year 2000 model but the Green is for the tail light bulb, not for the stop bulb (stop bulb is still OY):

I have also attached the full page in PDF.

Perhaps your car is early 2001 and it has tail light wire colours as the 2000 models. In any case, you should look for OY wire at your Right tail lamp for the stop bulb and check the continuity from OY at SLCM to OY at the lamp connector. If the OY continuity is good, then you will need to try to fix the SLCM.

It seems that the SLCM chip controlling the Right stop light is the one marked with a red dot on this picture:

Have another look at the marked chip with a magnifying glass, look for any cracks in its body or deteriorated solder on any of its legs. You can try carefully re-soldering its 4 legs. If it does not solve the issue, you can try with replacing the chip with a new one.

As for the mentioned 5-legged transistors at the side of the PC board, this applies to the X-100 SLCM-s, not to your X-300 SLCM, so you will not find them inside. Picture of X-100 SLCM:

 

This can not be true as my car ain't X-100. I sadly did not take any pictures of my board to show. If you follow the trace from the correct pin. It will go to the right side transistors or if the transistors are missing, trace will go elswhere. I can't and will not arque about the burnt transistors you are referring to. They can easily be feeding the lights. Then there is that my car is 2000 model. Not 2001.

 

I am not sure whether "X300" and "X100" written on the SLCM refer to the Jag models or whether they are simply SLCM numbers. I have not seen any other Jag X308 module carrying any number like that. For example, the BPM has a similar yellow sticker with only "BODY PROCESSOR MODULE" written on it and no "X300" or "X308" prefix.

In any case, the first of the pictures I posted above is of the PC board from an "X300" module (3 Chips) and the second one is of the PC board from an "X100" module (5 transistor-like chips).