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Main Switch Circuit: Procedure

  1. INSPECT STEERING PAD SWITCH RH 
    1. Remove the steering pad switch RH. Refer to REMOVAL .
    2. Disconnect the z9 connector from the spiral cable.
      Fig 1: Z9 Connector
      GTY363059Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *1 Component without harness connected
      (Steering Pad Switch RH)
      *2 Lane Keeping Assist Main Switch
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      z9-4 - z9-6 Lane keeping assist main switch ON Below 2.5 Ω
      z9-4 - z9-6 Lane keeping assist main switch OFF 10 kΩ or higher
    4. Reconnect the connector.
    5. Reinstall the steering pad switch RH. Refer to INSTALLATION .

    NG → See step   8 

    OK: Go to next step 

  2. CHECK AND REPLACE SPIRAL CABLE SUB-ASSEMBLY 
    NOTE:

    The spiral cable is an important part of the SRS airbag system. Incorrect removal or installation of the spiral cable may cause airbag deployment. Be sure to read information shown in the brackets.

    1. Remove the spiral cable sub-assembly. Refer to REMOVAL .
      Fig 2: View Of Spiral Cable Sub-Assembly And Connector Terminals
      GTY218325Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      z9-4 - L52-11 (DIST) The spiral cable position is center Below 1 Ω
      The spiral cable position is 2.5 rotations to the left
      The spiral cable position is 2.5 rotations to the right
      z9-6 - L52-2 (ECC) The spiral cable position is center Below 1 Ω
      The spiral cable position is 2.5 rotations to the left
      The spiral cable position is 2.5 rotations to the right
      TEXT IN ILLUSTRATION

      *1 Component without harness connected
      (Spiral Cable Sub-assembly)

      HINT: 

      The spiral cable makes a maximum of approximately 5 rotations.

    3. Install the spiral cable sub-assembly. Refer to INSTALLATION .

    NG → See step   6 

    OK: Go to next step 

  3. CHECK HARNESS AND CONNECTOR (SPIRAL CABLE - DRIVING SUPPORT ECU) 
    1. Disconnect the driving support ECU connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      L52-11 (DIST) - L60-6 (SPSW) Always Below 1 Ω
      L52-11 (DIST) - Body ground Always 10 kΩ or higher
    3. Reconnect the driving support ECU connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (SPIRAL CABLE - DRIVING SUPPORT ECU) 

    OK: Go to next step 

  4. CHECK HARNESS AND CONNECTOR (BODY GROUND CIRCUIT) 
    1. Disconnect the spiral cable connector.
      Fig 3: View Of Spiral Cable Connector Terminals
      GTY235518Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      L52-2 (ECC) - Body ground Always Below 1 Ω
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Spiral Cable Sub-assembly)
    3. Reconnect the connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (BODY GROUND CIRCUIT) 

    OK: Go to next step 

  5. INSPECT DRIVING SUPPORT ECU 
    1. Turn the power switch on (IG).
      Fig 4: Identifying Driving Support ECU Connector Terminals
      GTY235232Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      L60-6 (SPSW) - Body ground
      • Power switch on (IG)
      • Lane keeping assist main switch ON
      6 to 7 V
      • Power switch on (IG)
      • Lane keeping assist main switch OFF
      10 to 14 V
      TEXT IN ILLUSTRATION

      *1 Component without harness connected
      (Driving Support ECU)

    NG → See step   9 

    OK → See step   7 

  6. REPLACE SPIRAL CABLE SUB-ASSEMBLY. Refer to  REMOVAL 
  7. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE 
  8. REPLACE STEERING PAD SWITCH RH. Refer to  REMOVAL 
  9. REPLACE DRIVING SUPPORT ECU. Refer to  REMOVAL