What system did you use to check for faults?
You need to use dealer-level equipment such as
Tech 2 or Vaux-com to access the alarm activation history log.
Is the heated rear windscreen ok? The pane break system uses the heater element as the break sensor and a broken track on the screen element will cause a fault.
There are also pane break sensors in the rear side windows. Remove the panels below and check the resistance across the glass. If it's open circuit just join the two wires together if you dont want to fit a new window.
Is the car battery in good condition?
victor
April 2009