Replacing volumetric sensor

[Plodwyn]

Used the car today after 3 wks and bleeped 3 times when opened. When locked the alarm went off and the LED light flashes 3 times which I think is the volumetric sensor being activated. Tried this four times and always the same also the central locking light stays on all the time, now thinking its the volumetric sensors are faulty, Is this an easy jobbie or one for dealer/ auto electrician?

 

[edde]

Check the air vents in the car are closed and not pointing to at sensors.

The sensors can be very sensative you can swop the wires on the sensor round and it reduces there sensitivity