davie Posted February 6, 2010 Share Posted February 6, 2010 Hey Folks, Desperate for help here with an alarm issue. For the last month its been going off randomly after i have set it with fob and gone away. Parked different places - different times and so on, no difference. Its been plugged into autologic and all that showed was the last few activations, latest being the volumetric sensor, so i borrowed a known good one for a few days - no change. Autologic have suggested to garage that it must be an ecu/spider fault and be best to change both to cure. Its an expensive gamble without definite proof of being needed/going to cure it. The only other thing we have found is once the alarm activates and i ignore it when i return to car the doors are unlocked but when i open door the alarm sounds. Any ideas?? Thanks Davie Quote Link to comment Share on other sites More sharing options...
Dave W Posted February 7, 2010 Share Posted February 7, 2010 Do you know which alarm you have ? The year of the Defender will help, the ECU part number would be better. My guess would be a TD5 with a YWCxxx280, 2002 on. The bit about it unlocking the doors may be a clue, there are a few instances on the above ECU where the doors are automatically unlocked. One of them is if the alarms internal inertia switch is triggered (this is built into the ECU, not the fuel pump one). It could also be a faulty switch on the driver's door lock. You could try localising the problem by disconnecting bits one by one. The volumetric sensor can be unplugged and the alarm will work quite happily without it. Same goes for the bonnet alarm switch and the door switches. Even the alarm sounder can be disconnected although that is slightly more complicated than just unplugging it unless you have a soundproof bin to throw it in while it's battery runs down The fact that the doors are unlocking on there own does smack of an ECU fault as the alarm ECU controls the door locks with a completely independent circuit from the alarm functions. Quote Link to comment Share on other sites More sharing options...
davie Posted February 7, 2010 Author Share Posted February 7, 2010 duhh me - its a 2003 defender. How would i find out what alarm i have? - all i know is its the one that was in when i bought it. Am guessing to disable a door switch i have to take the trim panels etc off? Ahh more broken clips await me. davie Quote Link to comment Share on other sites More sharing options...
Dave W Posted February 7, 2010 Share Posted February 7, 2010 It will be a YWC106280 then and won't have a spider. At one time there used to be a glut of these on ebay but in recent months I've only seen one but if you can get hold of one at a decent price it'd be worth keeping an eye out. You can disconnect the door electrics altogether if you want to rule the drivers door out. There is a multi connector tucked inside the bulkhead where the wires come out of the door and into the bulkhead. If you disconnect the multiplug you'll effectively disable the central locking and the switch on that side. If you have electric windows I can't remember if it's a combined plug or two separate. If it's two separate ones the central locking will be the one with the most wires, if it's all one plug you'll have to live without electric windows at that side until you rule it out as well as having to use the key to unlock the door. The volumetric sensor has a small plug on the back of it that can be disconnected, the bonnet switch also has a multi-plug that plugs into the bottom of it. The door switches are screwed to the bulkhead with a single screw each, undo the screw and pull the switch out, disconnect the spade connector and put some tape around it to ensure it can't touch any metalwork. If none of those make any difference then you're looking at an ECU change. The ECU is located just behind the instrument panel on the dash, it's a green box with two plugs going into it. A replacement unit will need to be put on a testbook or similar to match your key fobs. Quote Link to comment Share on other sites More sharing options...
davie Posted February 8, 2010 Author Share Posted February 8, 2010 thanks for the ideas, thats the rear door switch removed and it looks pretty green and horrible all over the metal contacts so i will wait a day or two and see if there is any change. only other thing i remembered today was autologic asking the mechanic if the hazard lights flashed when alarm was going off - they do. Dont know the significance of this but will see if anyone has any ideas? Davie Quote Link to comment Share on other sites More sharing options...
davie Posted February 16, 2010 Author Share Posted February 16, 2010 Thought i should update. Thats 8 days since i removed the rear door switch and its been sooooooo peaceful, not a single alarm activation. Kinda sad though cause its led onto another problem, water leak somewhere around the rear cappings or roof. door switch was green and corroded when i took it out and much wetness just below cappings. Ahh the joys of landrovers!!! Happy me though, passed its mot yesterday with no worries..............even if the old one ran out feb 2 OOOOOOPS ME davie Quote Link to comment Share on other sites More sharing options...
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