ENTRY AND START SYSTEM Power Source Mode does not Change

DESCRIPTION

When the certification ECU has detected the key inside the cabin before the brake pedal is depressed, the power source mode can be changed in the following order sequentially by pressing the power switch: OFF → ON (ACC) → ON (IG) → OFF.

When one of the DTCs shown in the illustration below is detected, troubleshoot the DTC(s) by following the troubleshooting procedure relevant to the DTC(s). If the power source mode still cannot be changed normally, despite troubleshooting, one of the following may have occurred:


A000U7KE04

WIRING DIAGRAM

A000VB6E08

CAUTION / NOTICE / HINT

Tech Tips

If the vehicle is in key cancel mode, change to normal mode Click here.

PROCEDURE


  1. CHECK DTC OUTPUT


    1. Clear the DTCs Click here.

    2. Check whether a DTC is output 5 seconds after the power switch is turned ON (IG).

      Result
      Display (DTC output) Proceed to
      No DTC output A
      DTC output B

    B

    GO TO ENTRY AND START SYSTEM (DIAGNOSTIC TROUBLE CODE CHART) Click here

    A

  2. CHECK ENTRY AND START SYSTEM

    A000YDFE01
    *1 Power Switch
    *2 Key

    1. Remove the battery of the electrical key transmitter Click here.

    2. With the brake pedal depressed, touch the LEXUS mark of the key to the power switch.

    3. When operating the power switch, check whether the power switch changes to ON (ACC) or ON (IG).

      Tech Tips


      • When the electrical key transmitter cannot be verified even when it is in the operational area, the hybrid control system start check can be performed by removing the transmitter battery from the electrical key transmitter and holding the transmitter against the power switch.

      • When performing the check, if the power switch turns ON (ACC) or ON (IG), there is a problem with key certification inside the cabin.

      Result
      Result Proceed to
      Does not change to ON (ACC) A
      Does not change to ON (IG) B
      Does not change to ON (ACC) and ON (IG) C
      Changes to ON (ACC) and ON (IG) D

    B

    INSPECT FUSE (AM2) Click here

    C

    INSPECT FUSE (AM2) Click here

    D

    GO TO ENTRY AND START SYSTEM (ROOM OSCILLATOR DOES NOT RECOGNIZE KEY) Click here

    A

  3. INSPECT FUSE (AM2)


    1. Remove the AM2 fuse from the passenger side junction block.

    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance
      Tester Connection Condition Specified Condition
      AM2 fuse Always Below 1 Ω

    NG

    REPLACE FUSE

    OK

  4. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - BATTERY, BODY GROUND)

    A000YE3E03
    *1 Front view of wire harness connector: (to Main Body ECU)

    1. Disconnect the L13, L12, DF and DA main body ECU connectors.

    2. Measure the voltage and resistance according to the value(s) in the table below.

      Standard voltage
      Tester Connection Condition Specified Condition
      L13-6 (AM1) - Body ground Always 11 to 14 V
      L12-1 (AM2) - Body ground Always 11 to 14 V
      DF-1 - Body ground Always 11 to 14 V
      Standard resistance
      Tester Connection Condition Specified Condition
      L13-22 (ACCD) - DA-19 Always Below 1 Ω
      DA-40 (GND1) - Body ground Always Below 1 Ω
      L13-22 (ACCD) or DA-19 - Body ground Always 10 kΩ or higher

    OK

    REPLACE MAIN BODY ECU

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  5. INSPECT FUSE (AM2)


    1. Remove the AM2 fuse from the passenger side junction block.

    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance
      Tester Connection Condition Specified Condition
      AM2 fuse Always Below 1 Ω

    NG

    REPLACE FUSE

    OK

  6. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - BATTERY, BODY GROUND)

    A000UUWE03
    *1 Front view of wire harness connector: (to Main Body ECU)

    1. Disconnect the L13, L12, DF and DA main body ECU connectors.

    2. Measure the voltage and resistance according to the value(s) in the table below.

      Standard voltage
      Tester Connection Condition Specified Condition
      L13-6 (AM1) - Body ground Always 11 to 14 V
      L12-1 (AM2) - Body ground Always 11 to 14 V
      DF-1 - Body ground Always 11 to 14 V
      Standard resistance
      Tester Connection Condition Specified Condition
      L13-3 (IG1D) - DA-32 Always Below 1 Ω
      DA-40 (GND1) - Body ground Always Below 1 Ω
      L13-3 (IG1D) or DA-32 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. INSPECT IGNITION RELAY NO. 2 (IG2)

    A000UE5E06
    *a Ignition Relay No. 2 (IG2)

    1. Remove the ignition relay No. 2 (IG2) from the engine room No. 2 junction block.

    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance
      Tester Connection Condition Specified Condition
      3 - 5 When battery voltage is applied to terminals 1 and 2 Below 1 Ω
      3 - 5 When battery voltage is not applied to terminals 1 and 2 10 kΩ or higher

    NG

    REPLACE RELAY Click here

    OK

  8. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - IGNITION RELAY NO. 2 (IG2))

    A000UGOE04
    *1 Front view of wire harness connector: (to Main Body ECU)
    *2 Engine Room No. 2 Junction Block
    *3 Ignition Relay No. 2 (IG2)

    1. Disconnect the L12 main body ECU connector.

    2. Remove the ignition relay No. 2 (IG2) from the engine room No. 2 junction block.

    3. Measure the resistance according to the value(s) in the table below.

      Standard resistance
      Tester Connection Condition Specified Condition
      L12-11 (IG2D) - Ignition relay No. 2 (IG2) relay terminal 1 Always Below 1 Ω
      Ignition relay No. 2 (IG2) relay terminal 2 - Body ground Always Below 1 Ω
      L12-11 (IG2D) or ignition relay No. 2 (IG2) relay terminal 1 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. INSPECT FUSE (ECU-IG, P IG2)


    1. Remove the ECU-IG fuse from the engine room No. 2 junction block.

    2. Remove the P IG2 fuse from the passenger side junction block.

    3. Measure the resistance according to the value(s) in the table below.

      Standard resistance
      Tester Connection Condition Specified Condition
      ECU-IG fuse Always Below 1 Ω
      P IG2 fuse Always Below 1 Ω

    NG

    REPLACE FUSE

    OK

  10. CHECK HARNESS AND CONNECTOR (STEERING LOCK ECU - IGNITION RELAY NO. 2 (IG2))

    A000ZTUE02
    *1 Front view of wire harness connector: (to Steering Lock ECU)
    *2 Engine Room No. 2 Junction Block
    *3 Ignition Relay No. 2 (IG2)

    1. Disconnect the L33 steering lock ECU connector.

    2. Remove the ignition relay No. 2 (IG2) from the engine room No. 2 junction block.

    3. Measure the voltage and resistance according to the value(s) in the table below.

      Standard voltage
      Tester Connection Condition Specified Condition
      Ignition relay No. 2 (IG2) relay terminal 5 - Body ground Always 11 to 14 V
      Standard resistance
      Tester Connection Condition Specified Condition
      L33-6 (IG2) - Ignition relay No. 2 (IG2) relay terminal 3 Always Below 1 Ω
      L33-6 (IG2) or ignition relay No. 2 (IG2) relay terminal 3 - Body ground Always 10 kΩ or higher

    OK

    REPLACE MAIN BODY ECU

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  11. INSPECT FUSE (AM2)


    1. Remove the AM2 fuse from the passenger side junction block.

    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance
      Tester Connection Condition Specified Condition
      AM2 fuse Always Below 1 Ω

    NG

    REPLACE FUSE

    OK

  12. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - BATTERY, BODY GROUND)

    A000XYXE04
    *1 Front view of wire harness connector: (to Main Body ECU)

    1. Disconnect the L13, L12 and DA main body ECU connectors.

    2. Measure the voltage and resistance according to the value(s) in the table below.

      Standard voltage
      Tester Connection Condition Specified Condition
      L13-6 (AM1) - Body ground Always 11 to 14 V
      L12-1 (AM2) - Body ground Always 11 to 14 V
      Standard resistance
      Tester Connection Condition Specified Condition
      DA-40 (GND1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  13. INSPECT POWER SWITCH

    A000TONE30
    *1 Component without harness connected: (Power Switch)

    1. Disconnect the L36 power switch connector.

    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance
      Tester Connection Switch Condition Specified Condition
      7 (SS1) - 5 (GND) Pushed Below 1 Ω
      2 (SS2) - 5 (GND) Pushed Below 1 Ω
      7 (SS1) - 5 (GND) Not pushed 10 kΩ or higher
      2 (SS2) - 5 (GND) Not pushed 10 kΩ or higher

    NG

    REPLACE POWER SWITCH Click here

    OK

  14. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - POWER SWITCH, BODY GROUND)

    A000U5DE04
    *1 Front view of wire harness connector: (to Main Body ECU)
    *2 Front view of wire harness connector: (to Power Switch)

    1. Disconnect the L13 main body ECU connector.

    2. Disconnect the L36 power switch connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard resistance
      Tester Connection Condition Specified Condition
      L13-17 (SSW1) - L36-7 (SS1) Always Below 1 Ω
      L13-16 (SSW2) - L36-2 (SS2) Always Below 1 Ω
      L36-5 (GND) - Body ground Always Below 1 Ω
      L13-17 (SSW1) or L36-7 (SS1) - Body ground Always 10 kΩ or higher
      L13-16 (SSW2) or L36-2 (SS2) - Body ground Always 10 kΩ or higher

    OK

    REPLACE MAIN BODY ECU

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR