Smart Key System (For Start Function) System Description

Vehicle Interior. Corolla. Zre142 Aze141
Theft Deterrent Keyless Entry. Corolla. Zre142 Aze141

  1. PUSH-BUTTON START FUNCTION DESCRIPTION

  1. FUNCTION OF COMPONENT

  1. SYSTEM FUNCTION

  1. CONSTRUCTION AND OPERATION

  1. PUSH-BUTTON START FUNCTION OPERATION

  1. WHEN KEY BATTERY IS LOW

  1. DIAGNOSIS

Smart Key System (For Start Function) -- System Description



PUSH-BUTTON START FUNCTION DESCRIPTION

  1. The push-button start function uses a push-type engine switch, which the driver can operate by merely carrying the electrical key. This system consists primarily of the main body ECU (instrument panel junction block), engine switch, ID code box (immobiliser code ECU), steering lock ECU, electrical key, ACC relay, IG1 relay, IG2 relay and certification ECU (smart key ECU assembly). The main body ECU (instrument panel junction block) controls the function. This function operates in cooperation with the smart key system.


FUNCTION OF COMPONENT

Component
Function
Engine switch
  1. Transponder key amplifier
  1. Transmits engine switch signal to main body ECU (instrument panel junction block).
  2. Informs driver of power source mode or system abnormality with illumination of indicator light.
  3. Receives ID code and transmits it to certification ECU (smart key ECU assembly) when key battery is low.
Electrical key
Receives signals from oscillators and returns ID code to door control receiver.
Indoor oscillator
  1. Front and rear
Receives request signals from certification ECU (smart key ECU assembly) and forms detection area in vehicle interior.
Steering lock ECU
Receives lock/unlock request signals from certification ECU (smart key ECU assembly) and main body ECU (instrument panel junction block).
Stop light switch
Outputs state of brake pedal to main body ECU (instrument panel junction block).
Door control receiver
Receives ID code from electrical key and transmits it to certification ECU (smart key ECU assembly).
Main body ECU (instrument panel junction block)
  1. Changes power source mode in 4 stages (off, on (ACC), on (IG), start) in accordance with shift position and state of stop light switch.
  2. Controls push-button start function in accordance with signals received from switches and each ECU.
Certification ECU (smart key ECU assembly)
Certifies ID code received from door control receiver and transmits certification results to ID code box (immobiliser code ECU) and steering lock ECU.
ID code box (immobiliser code ECU)
Receives steering unlock or engine immobiliser unset signals from certification ECU (smart key ECU assembly), certifies them, and transmits each unset signal to steering lock ECU or ECM.
ECM
  1. Receives engine start request signal from main body ECU (instrument panel junction block), turns ON ST relay, and starts engine.
  2. Receives signal from ID code box (immobiliser code ECU) and performs engine ignition and injection.

SYSTEM FUNCTION
The electric controls of the push-button start function are described below:

Control
Outline
Engine switch control
When driver operates engine switch with electrical key in driver's possession, certification ECU (smart key ECU assembly) starts indoor oscillator, which transmits request signal to electrical key. Upon receiving this signal, the electrical key transmits ID code matching result signal to main body ECU (instrument panel junction block).
Diagnosis
When main body ECU (instrument panel junction block) detects malfunction, main body ECU (instrument panel junction block) diagnoses and memorizes failed section.

CONSTRUCTION AND OPERATION
Corolla. Zre142 Aze141.Theft Deterrent Keyless Entry.Smart Key System (For Entry Function).Smart Key System (For Start Function) System Description

  1. Engine Switch
    The engine switch consists of a momentary type switch, 2 color (amber, green) LEDs, and a transponder key amplifier.

    1. The amber and green LEDs are for the indicator lights. The driver can check the present power source mode and whether the engine can start in accordance with the illumination state of the indicator light.
    2. When the main body ECU (instrument panel junction block) detects an abnormality in the push-button start function, it makes the amber indicator light flash. If the engine is stopped in this state, it may not be possible to restart it.

  2. Indicator Light Condition

    Engine Switch Indicator Light Condition
    Power Source Mode/Condition
    		Indicator Light Condition
    Brake pedal released
    		Brake pedal depressed, shift lever in P or N
    off
    		OFF
    		ON (Green)
    (When key and vehicle IDs match)
    on (ACC, IG)
    		ON (Amber)
    		ON (Green)
    Engine running
    		OFF
    		OFF
    Steering lock not unlocked
    		Flashes (Green) for 15 sec.
    		Flashes (Green) for 15 sec.
    System malfunction
    		Flashes (Amber) for 15 sec.
    		Flashes (Amber) for 15 sec.

  3. Main body ECU (instrument panel junction block)
    The main body ECU (instrument panel junction block) consists of the IG1 and IG2 relay actuation circuits and CPU.

    HINT:
    Before removing the battery, make sure to turn the engine switch off. The main body ECU (instrument panel junction block) constantly stores the present power source mode in its memory. Therefore, if the main body ECU (instrument panel junction block) is interrupted by disconnecting the battery, the main body ECU (instrument panel junction block) restores the power source mode after the battery is reconnected. For this reason, if the battery is disconnected when the engine switch is not off, the power will be restored to the vehicle at the same time the power is restored to the main body ECU (instrument panel junction block) (by reconnecting the battery).

PUSH-BUTTON START FUNCTION OPERATION

  1. This system has different power source mode patterns depending on the brake pedal condition and shift lever position.

    Brake Pedal
    		Shift Lever
    		Power Source Mode Pattern
    Depressed
    		P or N
    		When the engine switch is pushed once.
    1. off → engine start
    2. on (ACC) → engine start
    3. on (IG) → engine start
    Not depressed
    		P
    		Each time the engine switch is pushed.
    1. off → on (ACC) → on (IG) → off
    Except P
    		Each time the engine switch is pushed.
    1. off → on (ACC) → on (IG) → on (ACC)
    -
    		P
    		When the engine switch is pushed with power source mode on (IG) (engine running).
    1. on (IG) → off
    -
    		Except P
    		When the engine switch is pushed with power source mode on (IG) (engine running).
    1. on (IG) → on (ACC)
    When the battery of the key is low, the push-button start function can be operated by holding the key against the engine switch.
    1. After approximately 1 hour has passed with the engine switch on (ACC) and the shift position in P, the main body ECU (instrument panel junction block) will automatically cut the power supply (the power source mode changes to off).

    2. The illustration below shows the transition of power source modes.
      Transition of power source mode:


      Corolla. Zre142 Aze141.Theft Deterrent Keyless Entry.Smart Key System (For Entry Function).Smart Key System (For Start Function) System Description

      HINT:
      While the vehicle is being driven normally, operation of the engine switch is disabled. However, if the engine must be stopped in an emergency while the vehicle is being driven, pressing the engine switch for 3 seconds or more stops the engine. Power source mode changes from start to on (ACC).

WHEN KEY BATTERY IS LOW


    Corolla. Zre142 Aze141.Theft Deterrent Keyless Entry.Smart Key System (For Entry Function).Smart Key System (For Start Function) System Description

  1. To operate the push-button start function when the key battery is low, hold the key close to the engine switch with the brake pedal depressed.

  2. The main body ECU (instrument panel junction block) transmits a key verification request signal to the certification ECU (smart key ECU assembly).

  3. The certification ECU (smart key ECU assembly) does not receive an ID code response from the door control receiver, so it actuates the transponder key amplifier built into the engine switch.

  4. The transponder key amplifier outputs an engine immobiliser radio wave to the key.

  5. The key receives the radio wave, and returns a radio wave response to the transponder key amplifier.

  6. The transponder key amplifier combines the key ID codes with the radio wave response, and transmits it to the certification ECU (smart key ECU assembly).

  7. The certification ECU (smart key ECU assembly) judges and verifies the ID code, and transmits a key verification OK signal to the main body ECU (instrument panel junction block). The buzzer in the combination meter sounds at the same time.

  8. After the buzzer sounds, if the engine switch is pressed within 5 seconds with the brake pedal not depressed, the power source mode changes to on (ACC) or on (IG), the same as in the normal condition.


DIAGNOSIS
The main body ECU (instrument panel junction block) can detect malfunctions in the push-button start function when the power source mode is on (IG).
When the ECU detects a malfunction, the amber or green indicator light of the engine switch flashes to warn the driver. At the same time, the ECU stores a 5-digit DTC (Diagnostic Trouble Code) in the memory.
  1. The indicator light warning continues for 15 seconds even after the power source mode is changed to off.
  2. The DTC can be read by connecting the Techstream to the DLC3.
  3. The push-button start function cannot be operated if a malfunction occurs.