Occasionally the security light next to the shifter turns on dimly, both while parked (when running and shut off) and while driving. When I arm the system with the fob, it works as it should. When disarming, it dimly flashes twice, coinciding with the chirps. When driving, the light will come on dimly, and will blink in sync with the turn signals if I've activated them. Also it makes the wiper swipe if the turn signals are active. I can tell when this is about to happen because the light will light up dimly and remain dimly lit, then blink when the turn signals are activated. The wiper will then swipe, and sometimes keeps swiping even after the turn signals disengage.

I have unplugged the wiper motor, which of course makes the wiper stop, but the dim glow is still present on occasion so I don't think it's related to the wiper motor. The reason I think it might be related to the security system is that the light dimly blinks in sync with the chirps when disarming.

On two occasions I have received a message saying "rear bulb failure". There is no failure tho, at least when I get out to check. And the lights aren't even on...

It's not all the time, but does occur randomly and somewhat frequently. Any ideas? Thank you

 

The SCLM is located beneath the fuse box in the boot. It is mounted at the lowest point in the compartment and will sometimes corrode at the plug. Try disconnecting the battery and unplugging the module and use electrical contact cleaner and a soft brush to remove the corrosion.

 

Check my logic on this: the security light still glows dimly from time to time. Often if I turn the headlights on and then off, it quits glowing. Here's what I think. The security module is the only thing that can turn the security light on. It is also the only place where the headlight and marker light circuits intersect with the security light. It seems logical to assume that energy is somehow shorting across from the headlight circuit to the security light somewhere within the security module. Therefore, the security module needs to be repaired.

Make sense?

 

Or a chafed cable / bad power / ground.

 

Battery voltage low, first thing i would check.

 

Low Voltage does cause these cars to remit some weird codes and actions.

But, as stated below, if the problem still exists after checking the battery/voltage, then it's probably the SLCM.

There are hundreds of posts of problems happening that all go back to the SLCM.

The one key part of your statement was when you mentioned the rear lights would act up.
As stated in another post, the only place that all these problems intersect is the SLCM.

SLCM's are readily available on ebay.

Make sure you have the right code.
Also, make sure you match the code on your key fob too.

 

I should have mentioned that in the interim from when I first posted, I did check the battery and the connections. Battery is 12.7 volts with the car not running, and the battery is less than a year old. The connections are all pristine.

I will remove the security module again now that I've sort of parked the car for winter. I will examine the part numbers to figure out what I'm looking for on eBay. I may have more questions about what to order.

I see that used ones are not terribly expensive on eBay. What will happen when I install another module? Will I have to reprogram the fobs? The memory doesn't have to be flashed? Once I determine the correct part numbers, can I just plug it in?

Thank you all for your help.

 

The SLCM is a dealer level programmable module. Once you swap the module your keys want start the car. They RFI's have to be programmed to the module. The fobs will need programming also but you can perform that.
Remove the spare tire and check the wall of the tire for a large decal. That is the VCATS list the required numbers for the SLCM will be listed if the decal is there. It is about 10 inches by 24 inches.

 

I see a list titled VCATS, is that what you're referring to? If I buy an SLCM with a part number that matches mine exactly, can I pop it in, reprogram my fobs, and be good to go? Or is dealer programming needed regardless of part number?

Just trying to get my arms around what to expect. Thank you!

 

That should do it.
Make sure you match the key fob codes too, if available.

 

If you pop it in the car will not start. The module and key rfi's won't match. If you take it back out and put the old one in then you have a 50-50 chance that the car won't go to immobile thinking the ignition is being tampered with. The module has to be programmed.

This fellow has already experienced it:
https://www.jaguarforums.com/forum/x...cement-164357/

 

OP here, reviving the thread with new information. I found an SLM on eBay last winter and finally got the nerve to swap it to see what happens. Long story short, the SLM is not the problem. The eBay one hooked right up, no issues, but the light still glowed. I swapped back in my old one, and everything works fine, car starts, fobs work, but the glow remains.

So I'm almost 100% sure it's not the SLM. I am still convinced it's a short of some kind, because it glows dimly, not full blast, and it pulses with the blinkers. Not all the time, but definitely more frequent than it used to be.

Any ideas?

 

Is the security LED part of the gear selector circuit board, or is it a separate light that's just glued into the housing? I don't remember from when I took mine apart, but when I looked through the electrical guide I couldn't find any wiring diagrams to that LED. I figured it would be under the CAN network since that controls the rest of the gear selector, but I couldn't find info on transmitting/receiving a security light illumination signal. The transmission diagrams don't show the security LED as part of the gear selector. If it's controlled separately it could be hidden somewhere in the central locking diagrams maybe. I didn't see a message for security light illumination in the SCP messages index either, but that's not to say I couldn't have missed it.

FWIW mine blinks very dimly when the system is armed (which is when it's supposed to), at night you have to strain to see it.

 

Part of my problem is that I haven't been able to find any helpful wiring diagrams either. I'm largely guessing about what controls it. Today I even unplugged the chirp horn near the left front frame rail, because the LED occasionally blinks dimly with each chirp. Thinking maybe there is a short in the chirp speaker or something. No dice. It quit chirping when I locked/unlocked the doors, but the light still glowed, so I plugged the speaker back in.

So I had another idea. The headlight/ turn signal switch on the steering column. It's kind of a pain to replace it, but I might try that next. Wondering if that light switch is faulty, could current trickle backwards thru and end up at the LED? I dont know the answer but I don't know how the current is getting there. The LED is affected by the turn signals because it does blink dimly when the blinkers are on sometimes. Sometimes when I turn the lights on and off it will also make the LED behave correctly. So....that lead me to the headlight switch......maybe??