Ford Focus Owners Manual: Principle of operation

Engine immobiliser

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Coded keys

Note: Do not shield your keys with metal objects. This may prevent the receiver from recognising your key as a valid one. Note: Have all of your remaining keys erased and recoded if you lose a key ...

More about Ford Focus:

Ford Focus Evaporative Emission Canister Vent Solenoid
  Item Part Number Description 1 9E857 Evaporative Emission (EVAP) canister 2 9F945 EVAP canister vent solenoid Removal and Installation WARNING: Do not smoke, carry lighted tobacco or have an open flame of any type when working on ...