See also:

Theft deterrent system
Immobilizer system The vehicle's keys have built-in transponder chips that prevent the hybrid system from starting if the key has not been previously registered in the vehicle's on-board computer. ...

Engine compartment
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Noise from under vehicle after turning off the engine
Approximately five hours after the engine is turned off, you may hear sound coming from under the vehicle for several minutes. This is the sound of a fuel evaporation leakage check and, it does no ...