The engine immobiliser is armed automatically a short time after you have switched the ignition off.
The indicator in the instrument cluster will flash to confirm that the system is operating.
Coded keys
Disarming the engine immobiliserFord Focus Brake Booster - Removal and Installation
Item
Part Number
Description
1
2L523
Booster rod-to-pedal pin
2
W520212
Brake booster nut (4 required)
3
2005
Brake booster
Removal and Installation
Vehicles equipped with ABS
Remove the Hydraulic Control Unit ...