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System Description

  1. SMART KEY SYSTEM DESCRIPTION 
    1. The smart key system uses a push-type power switch, which the driver operates by inserting a key into the key slot or by merely carrying the key*. This system consists of a power source control ECU, power switch, key slot, key, ACC relay, IG1 relay, IG2 relay and transponder key ECU. The power source control ECU controls the system. This system operates in conjunction with the engine immobilizer system and the smart key system*. The table below shows the transition of the power switch, which depends on whether the brake pedal is depressed or released.

      HINT:

      *: w/ Smart key system (for door lock)

    BRAKE PEDAL AND POWER SWITCH OPERATION

    Brake Pedal Operation Power Switch Operation
    Released Power mode changes between OFF, ON (ACC) and ON (IG) power switch is pressed
    Depressed Power mode changes to ON (READY) from any power mode
  2. FUNCTION OF COMPONENT 
    FUNCTION OF COMPONENT

    Components Function
    Key
    • When driver inserts key into key slot, built-in transponder chip transmits ID code signal to transponder key amplifier which is provided in key slot.
    • For a vehicle with smart entry system (for door lock), if driver operates power switch with key in driver's possession, key receives signals from oscillators and transmits ID code to door control receiver.
    Key slot
    • Halfway switch: Detects whether key is inserted and outputs signal to transponder key ECU.
    • Full switch: Detects whether key is inserted and outputs signal to power source control ECU.
    • Transponder key amplifier and coil: Receives ID code signal from transponder chip which is built into key, and outputs it to transponder key ECU.
    • Key interlock solenoid: Power source control ECU operates this solenoid in accordance with power switch mode and shift position to keep key locked in key slot.
    Power switch
    • In accordance with shift position and stop light switch's condition, changes power modes in 4 stages as follows: OFF, ON (ACC), ON (IG) and ON (READY).
    • Power mode can be determined by illumination / flash / color of power switch indicator. Push button start system malfunctions can also be determined.
    • IG1 relay
    • IG2 relay
    • ACC relay
    		 Operates in accordance with power source control ECU to supply power to respective system.
    Stop light switch Outputs brake pedal's status to power source control ECU.
    Parking lock actuator
    • Operates in accordance with signals from transmission control ECU to actuate parking lock mechanism.
    • Detects actuation status of parking lock (whether shift position is P or other position) and outputs it to transmission control ECU.
    Power source control ECU Controls push button start system in accordance with signals received from switches and ECUs.
    Transponder key ECU
    • Controls engine immobilizer system by recognizing key ID code transmitted by transponder key amplifier.
    • Receives ID code check results from certification ECU*.
    • Transmits key ID code check results to power source control ECU.
    • Transmits hybrid control system start authorization signal to hybrid vehicle control ECU.
    Transmission control ECU
    • Actuates parking lock actuator upon receiving power switch OFF signal from power source control ECU.
    • Transmits actuation status of parking lock (whether shift position is P or other position) to power source control ECU.
    Hybrid vehicle control ECU
    • Starts hybrid control system in accordance with system start signal received from power source control ECU.
    • Receives hybrid control system start authorization signal from transponder key ECU.
    Certification ECU* Checks ID code received from door control receiver and transmits check results to transponder key ECU.

    HINT:

    *: w/ Smart key system (for door lock)

  3. SYSTEM FUNCTION 

    The electric controls of the smart key system are described below:

    OUTLINE CONTROL FUNCTION

    Control Outline
    Power switch control
    (w/o smart key system (for door lock))    		 Transponder key ECU checks ID code when key is inserted into key slot. Power source control ECU verifies check results and authorizes operation of switch.
    Power switch control
    (w/ smart key system (for door lock))
    • When driver operates power switch with key in driver's possession, power source control ECU starts indoor electrical key oscillator, which transmits request signal to key. Upon receiving this signal, key transmits ID code signal to certification ECU.
    • Transponder key ECU verifies check results received from certification ECU via BEAN and sends them to power source control ECU. Based on these results, power source control ECU authorizes operation of power switch.
    Auto P control While shift position is not P, if power switch is turned OFF, hybrid vehicle control ECU commands transmission control ECU to activate parking lock actuator and change shift position to P.
    Diagnosis When power source control ECU detects malfunction, power source control ECU diagnoses and memorizes malfunction.
  4. POWER SWITCH CONTROL (WITH KEY) 
    • When a key is inserted into the key slot and the transponder key ECU recognizes the ID code of the key, the power source control ECU authorizes operation of the power switch.
    • A power mode (OFF, ON (ACC) and ON (IG)) can be selected by pressing the power switch. Press, release and press the power switch until the desired power mode is selected (the power mode cycle in the order shown above). If the driver pushes the power switch while depressing the brake pedal (the stop light switch turns ON), the power mode will change to ON (READY) regardless of the previous power mode.
    • After approximately 1 hour has passed with the power switch ON (ACC) and the shift position in P, the power source control ECU will automatically turns OFF the power (the power mode changes to OFF).
    • The illustration below shows the transition of power modes.
      Fig 1: Identifying Transition Of Power Modes
      G04473179Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    HINT:

    While the vehicle is being driven normally, operation of the power switch is disabled. However, if the hybrid control system must be stopped in an emergency while the vehicle is being driven, pressing the power switch for at least 3 seconds can stop the hybrid control system. Power mode changes from ON (READY) to ON (ACC).

  5. DIAGNOSIS 

    If a malfunction occurs in the IG circuit, the power source control ECU will perform the controls listed in the table below and record a DTC.

    IG CIRCUIT MALFUNCTION DETAILS

    IG Circuit Malfunction Details
    Malfunction occurs during ON (IG) mode
    • Hold circuit in power source control ECU continues to supply power to IG1 and IG2 relays. At this time, power source control ECU begins flashing amber-colored indicator on power switch.
    • After power switch is set to OFF, power source control ECU continues flashing indicator on power switch for 15 seconds.
    • Hybrid system cannot be restarted.
    Malfunction occurs during ON (ACC) or OFF mode
    • When power switch is set to ON (IG) and malfunction is detected, power switch automatically turns OFF.
    • If same malfunction as above is detected continuously 3 times, power source control ECU begins flashing amber-colored indicator on power switch for 15 seconds.
    • Hybrid system cannot be restarted.
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