THEFT DETERRENT SYSTEM Ignition Switch Circuit

DESCRIPTION

The main body ECU (multiplex network body ECU) determines the ignition position (LOCK, ACC, ON) based on signals from the IG or ACC circuit.

WIRING DIAGRAM

A011TJHE01

INSPECTION PROCEDURE

Note

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

  1. READ VALUE USING TECHSTREAM

    1. Connect the Techstream to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn Techstream on.

    4. Enter the following menus: Body Electrical / Main Body / Data List.

    5. According to the display on the Techstream, read the Data List.

      Main Body (Main Body ECU (Multiplex Network Body ECU))
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      ACC SW Ignition switch/ON or OFF

      ON: Ignition switch ACC

      OFF: Ignition switch LOCK

      		 -
      IG SW Ignition switch/ON or OFF

      ON: Ignition switch ON

      OFF: Ignition switch LOCK or ACC

      		 -
      OK
      ON or OFF appears on the screen according to whether the ignition switch is in ON or is in LOCK or ACC.
    NG

    INSPECT IGNITION OR STARTER SWITCH ASSEMBLY Click here

    OK

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Click here

  2. INSPECT IGNITION OR STARTER SWITCH ASSEMBLY

    1. Remove the ignition or starter switch assembly Click here.

      A011UPME01

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 - 4 Ignition switch ON Below 1 Ω
      2 - 4 Ignition switch ACC Below 1 Ω
      Text in Illustration
      *1 LOCK
      *2 ACC
      *3 ON
      *4 START
      *a

      Component without harness connected

      (Ignition or Starter Switch Assembly)
    NG

    REPLACE IGNITION OR STARTER SWITCH ASSEMBLY Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (BATTERY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

    1. Disconnect the 3E instrument panel junction block assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      3E-1 - Body ground Always 11 to 14 V
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - BODY GROUND)

    1. Disconnect the 3B instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3B-7 - Body ground Always Below 1 Ω
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (IGNITION SWITCH ASSEMBLY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

    1. Disconnect the 3A instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I36-1 (IG1) - 3A-27 Always Below 1 Ω
      I36-1 (IG1) - Body ground Always 10 kΩ or higher
      I36-2 (ACC) - 3B-23 Always Below 1 Ω
      I36-2 (ACC) - Body ground Always 10 kΩ or higher
      I36-4 (AM1) - 3A-39 Always Below 1 Ω
      I36-4 (AM1) - Body ground Always 10 kΩ or higher
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here