Jouxy Any thanks for your prompt reply and advice provided. I have checked the battery, using a multi-meter and intelligent charger and the battery appears to be holding sufficient voltage. The one time I managed to start the vehicle was by setting the alarm, whilst sat inside, and forcing the alarm system to activate. On unlocking the vehicle, and de-arming the system via the key fob, the vehicle started. However, once the vehicle was switched off, and the alarm activated and subsequently deactivated, I was back to square one, which leads me to believe the immobiliser is not deactivating when deactivating/unlocking the vehicle.