When I unlock my car with the key, the alarm goes off . Is this normal?

 

Sounds like the usual suspects, alarm siren batteries leaking, possible water on CLP etc. I would first try disconnecting alarm siren under cowl and see what happens after that.

 

Alarm module replaced last year. Everything works normally using fob

 

No that is not normal. When your car is locked with the fob the anti-theft alarm is set. It seems that the alarm system (when you open the door with the key) recognizes the door opened, BUT does not recognizes you did it with your key. This is just a guess, but I would use some Deoxit5 (contact cleaner) or some Houdini (lock lubricant) and spray it through the key hole then insert your key and turn it several time. MAYBE it will free up a switch inside the door and then the alarm will recognize you used your key vice the alarm only seeing the door opened.

If that doesn't work, hopefully a scan from a good tool will give you a direction to follow.

 

Okay, I figured it out. I used the key to open the door because the battery had died. No battery, no communication to anti theft system. Alarm had it's own battery , so it went off. Works like it should now.

 

So I inherited my 2004 XF when my father passed. I had been maintaining it when I could but don't ever remember there being an alarm that would chirp when locking or unlocking. The 2004 owner's manual says it has an alarm and since it is quiet now can I assume the batteries in it are shot and leaked and destroyed the insides? The panic button on the key fob sounds the horn... Not any alarm. I'm wondering if I pull the cowl if I'll even find a siren in there as I never remember hearing an alarm siren chirp upon locking. Dang owner's manual is about as clear as mud on this... Is it an alarm siren that goes off or is it the horn?

Another just posted that they replaced their siren with Bosch #2198203226. Anyone know if this is an easy plug-n-play replacement? Assuming my 2004 even has one or if it is just hooked up to the horn?

 

IF your alarm button on the (OEM?) FOB sets off the horn, there is not a simple answer to your questions (BECAUSE) someone rewired the car to set off the horn. Do not buy the chirping (or any) siren until you figure out what was done to the wiring (and) what parts were added to set off the horn system your car was modified to. If you wish the car to have the siren, you'll have to 'restore' it to factory wiring (eliminate any added mods to the siren/horn systems). Good luck!


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