Hybrid Electric Vehicle Training Educator

Smart Key


  • information
  • technical details

The smart key and related electronic control units (ECUs) enable the vehicle's driver to place the smart key in a pocket or purse and approach the vehicle as though it is unlocked. As the smart key makes an electrical handshake with the electronics of the vehicle and the driver touches the driver's door handle, the door unlocks. This electrical handshake also prepared the vehicle for identification to the thief deterrent system.

With all doors locked, the driver and front passenger door oscillators form a smart key detection area outside of the vehicle by emitting smart key detection signals on a regular basis. Accordingly, the smart ECU will be able to check the identification code of the smart key in the detection areas.

With all doors locked, if a user presses the back door opener switch, the back door oscillator forms a smart key detection area outside of the vehicle by emitting signals. Again, the smart ECU will be able to check the identification code of the smart key in the detection area.

With all doors closed, if a user presses the lock switch on the outside door handle, the smart ECU will cause all the oscillators to emit signals, forming smart key detection areas outside the vehicle. The smart ECU determines that the smart key has been removed from the vehicle.

If a user operates the power switch while the smart key is in the user's possession, the smart ECU outputs a request signal to cause the room oscillator to emit signals in order to form a smart key detection area in the vehicle interior. The smart ECU can check the smart key's identification code.

Outside Electrical Key Oscillator
The outside electrical key oscillator receives the request signal from the certification ECU and generates an actuation area in the back door.

Indoor Electrical Key Oscillator
The indoor electrical key oscillators, located in the front, rear, and luggage areas, emit radio waves into the cabin to determine whether the key is in the interior actuation area.

Door Control Receiver
The door control receiver accepts the key and vehicle identification codes from the key and outputs them to the certification ECU.

Smart Key
The smart key outputs the key and vehicle identification codes upon receiving radio waves from the external antenna. It also transmits radio waves of the key switch operation signals and outputs the key and vehicle identification codes to the immobilizer code ECU upon receiving radio waves from the immobilizer amplifier built into the power switch.

System Components
The following is a list of system components related to the smart key:

  • Wireless door lock buttons (part of smart key)
  • Key fob to enter, helps start the hybrid system (part of smart key)
  • Mechanical key and transponder chip (part of smart key)
  • Vehicle door antenna (part of door handle)
  • Interior antenna (part of vehicle)
  • Back hatch antenna, outer (part of vehicle)
  • Wireless door lock receiver
  • Main body ECU (inside vehicle)

© 2012 National Alternative Fuels Training Consortium.

Smart Key

Smart Key

Smart Key Diagram

Smart Key Diagram: Smart Entry & Smart Start