996 Alarm Malfunction

[sheldonv8]

Hi everyone, can anybody help with this one....The alarm decided to go off on my 996 C2 when it was UNLOCKED in the garage.1st time it went off and stopped after 30secs, did this 3-4 times then went off and kept going continuously, stopped it by disconnecting the battery(which made my ears bleed!!).....Reconnected battery,nothing,then charged it over night...it was OK for a couple of days then false alarmed again,doh...

I then disconnected then alarm HORN (the one which beeps if the door is ajar) which made the screecher go off,fair enough..

Then i unplugged and removed the bracket holding the screecher and tilt sensor...The wiring connector for the tilt box was all green and corroded(good sign as something wrong), i left it off the car for a few days but the battery drained by 0.1 volt a day so i cleaned and refitted the bits....

NOW what happens is, when you lock the car it screeches twice with the indicators and once when its unlocked where before there was silence on locking/unlocking, the dash top light flashes fast for a bit(cant be arsed to count) and then settles to an on/off rhythm as normal.

So ??? should it screech or not, and if i leave the car locked how long will it be before the battery is flat??

The local Porsche dealer said i cant just buy a new tilt sensor(if thats what it is) cuz they are no longer fitted next to the battery(because they get wet...funny that) and would have to be retro fitted in the inside(V expensive)

HELP

[Richard Hamilton]

You must be in the UK, because you have the tilt sensor and alarm siren. The tilt sensors are notorious for filling up with water, and that's why they now fit a different one. The replacement goes under the left hand seat next to the alarm control module. I would say that the OPC is correct, as it happened on mine. Just like you, I started to get double-siren blips, rather than double-beeps.

You could prove the point by disconnecting the tilt sensor. Before you disconnect it (or the battery), SWITCH THE IGNITION ON. That will stop the siren going off (it has a backup battery inside it). Also, think about finding yourself a good independent Porsche specialist in your area - you will save a fortune on this sort of job.

[sheldonv8]

Yes your right, i am in the uk.....whats "OPC" stand for? Your right about main dealer prices, my local specialist,"Marque 21 Racing" concentrates on older stuff, (when he did the clutch and flywheel on my 996 last year it was the first he had done and did a great job sorting the knackered rear bushes and joints) but doesn't have diagnostic gear.

I went to "Cool it" in Martinstown,Dorchester to get the air con done....half hour to fit 2 matrix, a dryer and re-gas it, very experienced!!!

[Richard Hamilton]

Official Porsche Centre. I have heard good things about Noel at Cool-It. If Marque 21 haven't got any diagnostic gear, you might want to try JGM in Bournemouth (http://www.jmgarage.co.uk/) as they have a very good reputation. too

[p0rsch3]

where is the tilt sensor located on an 02 996 coupe? I think mine is causing same problem.

[Paul Fraser]

There might be something in the TSBs for an alarm modification. Worth a look.