It’s been raining on and off all day and will rain through the night. A short time ago, twice within about 10 minutes, the alarm started going off on my ‘03 VDP after days of behaving itself. Once I got it disabled the first time by hitting the unlock button on the fob, it did it again in short order once I’d try to lock it with the key.

After searching the forum, I went back and opened and firmly shut the trunk and bonnet, firmly closed all doors, and locked it with the key. So far it’s behaving ... but the night is young.

And....it just went off again. So much for the above bit of diagnostics!

Both previous times it alarmed and I used the key to lock it, I heard a single chirp (error tone per the owner’s manual). The only things in the list of conditions in the manual that seemed remotely plausible were a trunk/hood not properly latched, or an electrical failure in the tilt sensing system. (Don’t know if I have that.)

So, to my question: While I can see a wire exiting the area behind the right hand hood latch, I cannot for the life of me find anything that looks like a pressure switch on the trunk lid, latch (either upper or lower parts). Does anyone have a photo of the trunk switch to help me run it down or can you give me a description of its location?

My battery is also of uncertain lineage, and I will double check its top tomorrow to see if I can find an install date, but my recollection is when doing the prepurchase checks in August I saw nothing. I’ve had no hint that the battery is giving out. I can also swap out the fob batteries if anyone thinks that might be a contributing factor.

Many thanks for any and all guidance or thoughts.

Eliot

 

I would highly suspect the battery. These cars are very fickle to the need of power above 12v, any lower and you'll start getting ghosts. Many posts on this. Get your battery checked and most likely you'll need a new one.
I just changed over to an AGM (absorbed glass mat) battery about 6 months ago and that's worked quite well and has more amps (900 vs 750).

Other things to check, ...grounds and cables. If you have any corrosion on a ground mount, diligently clean it. If you have corrosion on either battery terminal cable, replace it, you won't get it out and it will keep corroding deep inside the shielding.
The corrosion means your battery isn't able to hold a good enough charge and is allowing the corrosion to accumulate.

 

I think the X308 has a diagnosis for LAST ALARM ACTIVATION in the setup and configuration tab WDS/IDS.

If that application is there, you can see what is triggering the security system.

That will get you closer with your diagnosis.

 

I don’t speak enough Jag to know what WDS/IDS is, but I’ll look around and see ... and I will have the battery checked tomorrow.

Thanks so much to you and Highhorse for your quick responses.

 

Small update: Battery checked out fine today. After the alarm was triggered three times last night, the car started without incident today, drove about 2.5 miles and it was reading 12.7-12.8v on the shop meter. I did find the numbers 1-14 scribed into the top of the battery suggesting a Jan. ‘14 install, which would suggest the battery is suspect. There is no manufacturing date tag on it that I can find after talking with the folks whose label is on it (not Interstate).

My mechanic thought it might be a switch inside the hood/trunk or door latches and suggested I leave it to let him try to sort through that question. If a new battery doesn’t do the trick, I’ll let him have it.

I’d like to disable to security system so I can lock the car without incident while getting this straightened out, but unless I am mistaken, there is no single fuse that would do that without turning off the backup lights, brake lights and other stuff. If I am mistaken, I sure would appreciate a heads up.

Since the battery I have — if the scratching on the top is any guide — appears to be closing in on 7 years since installation — I ordered an Interstate glass mat battery MTX-49/8H per the Interstate website, for installation tomorrow. The place I’m getting it said it was manufactured just 2 months ago so it should be very fresh. We’ll see how it performs. If I continue to have problems, off it goes to have the various latch switches checked out.

Eliot

 

I think you were spot on. I put in a new battery and all is quiet in my parking lot .... so far. Thanks for the guidance. I got the AGM Interstate. A little pricey, but there's a peace of mind factor. thank you again.

 

A new Interstate AGM battery appears to have done the trick ... at least so far. Thanks for chiming in. Most kind of you, sir.

 

How do you do this... Not sure what the nemonic means
Regards Stephen

 

WDS = Worldwide Diagnostic System
IDS = Integated Diagnostic Software
SDD = Symptom Driven Diagnostics

This post is in the General Tech Help section.

https://www.jaguarforums.com/forum/g...d-truth-32683/