Let's see. . . When you take away the battery of a current car, certain parts of the vehicle multiplexed system are deprogram, that is: today's cars have several boxes of fuses, they manage the closure, the windows, etc. . . And when the battery is replaced, these systems are deprogrammed, I will give you an example: the Scenic 2 when you take away the battery and replace the memory it has to upload and lower the crystals with a single pulsation does not work, and the solution is a multiplexed network research with its software (Renault Can Clip).
What is activated by the immobilization system is for a very clumsy thief. . . And normally these systems have high -end cars, that is, your Tourneo flagunea does not carry it. . . take the lifelong blockade. . .
I do not want to roll up more your problem will be a molten fuse question that when putting the new battery, it would have been burned. . . I say it from experience.
PS: I hope that is that and if it is voting, it costs nothing. . .