FixVault
Home › Lexus › 2008 › GX 470 › Repair and Diagnosis › Accessories & Equipment › Entertainment Systems › Audio/Visual › Audio And Visual System › Illumination Circuit › Inspection Procedure

Inspection Procedure

NOTE: The vehicle is equipped with an SRS (Supplemental Restraint System) which includes components such as the airbags. Before servicing (including removal or installation of parts), be sure to read the PRECAUTION in the Supplemental Restraint System (see AIRBAG SYSTEM ).
  1. CHECK ILLUMINATION 
    1. Check if the illumination for the steering pad switch, radio receiver, glove box, or others (hazard switch, cigarette lighter, etc.) comes on when the light control switch is turned to the HEAD or TAIL position.

      Result 

      RESULT CHART

      Result Proceed to
      Illumination comes on for all components except radio receiver A
      Illumination comes on for all components except steering pad switch B
      No illumination comes on C

    B: Go to step  4

    C:  GO TO LIGHTING SYSTEM

    A: Go to Next Step 

  2. CHECK HARNESS AND CONNECTOR (RADIO RECEIVER - BATTERY) 
    1. Disconnect the R1 receiver connector.
    2. Measure the voltage according to the value (s) in the table below.

      Standard voltage 

      VOLTAGE SPECIFIED CONDITIONS

      Tester Connection Switch Condition Specified Condition
      R1-2 (ILL+) - Body ground Light control switch OFF Below 1 V
      R1-2 (ILL+) - Body ground Light control switch TAIL or HEAD 11 to 14 V

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 1: Identifying R1 Receiver Connector Terminals
    G05266130Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to Next Step 

  3. CHECK HARNESS AND CONNECTOR (RHEOSTAT - RADIO RECEIVER AND BODY GROUND) 
    1. Disconnect the R12 rheostat connector.
    2. Disconnect the R1 receiver connector.
    3. Measure the resistance according to the value (s) in the table below.

      Standard resistance 

      RESISTANCE SPECIFIED CONDITION

      Tester Connection Condition Specified Condition
      R12-6 (ILL-) - R1-12 (ILL-) Always Below 1 Ω
      R12-6 (ILL-) - Body ground Always 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 2: Identifying R12 Rheostat And R1 Receiver Connector Terminals
    G05266131Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE 

  4. CHECK HARNESS AND CONNECTOR (SPIRAL CABLE - RADIO RECEIVER AND BATTERY) 
    1. Disconnect the C13 cable connector.
    2. Disconnect the R2 receiver connector.
    3. Measure the resistance according to the value (s) in the table below

      Standard resistance 

      RESISTANCE SPECIFIED CONDITION

      Tester Connection Condition Specified Condition
      C13-10 (EAU) - R2-6 (SWGND) Always Below 1 Ω
      C13-10 (EAU) - Body ground Always 10 kΩ or higher
    4. Measure the voltage according to the value (s) in the table below.

      Standard voltage 

      VOLTAGE SPECIFIED CONDITIONS

      Tester Connection Switch Condition Specified Condition
      C13-1 (ILL+) - Body ground Light control switch TAIL or HEAD 11 to 14 V
      C13-1 (ILL+) - Body ground Light control switch OFF Below 1 V

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 3: Identifying C13 Cable And R2 Receiver Connector Terminals
    G05266132Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to Next Step 

  5. INSPECT STEERING PAD SWITCH 
    1. Disconnect the A switch connector.
      Fig 4: Inspecting Steering Pad Switch
      G05266133Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Connect the positive (+) lead to terminal ILL+ (A-1) and the negative (-) lead to terminal EAU (A-10) of the steering pad switch connector.
    3. Check if the illumination for the steering pad switch comes on.

      Result 

      RESULT CHART

      Result Proceed to
      Illumination comes on for the steering pad switch LH and RH A
      Illumination comes on only for the steering pad switch LH B
      Illumination comes on only for the steering pad switch RH C

    B: Go to step  7

    C: REPLACE STEERING PAD SWITCH 

    A: Go to Next Step 

  6. INSPECT SPIRAL CABLE 
    1. Disconnect the C13 and A cable connectors
    2. Measure the resistance according to the value (s) in the table below.

      Standard resistance 

      RESISTANCE SPECIFIED CONDITION

      Tester Connection Spiral Cable Position Specified Condition
      C13-10 (EAU) - A-10 (EAU) Center Below 1 Ω
      2.5 rotations to the left
      2.5 rotations to the right
      C13-1 (ILL+) - A-1 (ILL+) Center Below 1 Ω
      2.5 rotations to the left
      2.5 rotations to the right
    NOTE: The spiral cable is an important part of the SRS airbag system. Incorrect removal or installation of the spiral cable may prevent the airbag from deploying. Be sure to read the PRECAUTION for the supplemental restraint system (see AIRBAG SYSTEM ).

    NG: REPLACE SPIRAL CABLE 

    Fig 5: Identifying C13 And A Cable Connector Terminals
    G05266134Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: REPLACE RADIO RECEIVER 

  7. INSPECT STEERING PAD SWITCH CABLE 
    1. Disconnect the steering pad switch LH and steering pad RH
      Fig 6: Identifying Steering Pad Switch LH And RH Connector Terminals
      G04966987Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value (s) in the table below.

      Standard resistance 

      RESISTANCE SPECIFIED CONDITION

      Tester Connection Condition Specified Condition
      LH-1 - RH-1 Always Below 1 Ω
      LH-2 - RH-2 Always Below 1 Ω
      LH-3 - RH-3 Always Below 1 Ω
      LH-4 - RH-4 Always Below 1 Ω
      LH-5 - RH-5 Always Below 1 Ω
      LH-6 - RH-6 Always Below 1 Ω
      LH-7 - RH-7 Always Below 1 Ω
      LH-8 - RH-8 Always Below 1 Ω
      LH-1 - Body ground Always 10 kΩ or higher
      LH-2 - Body ground Always 10 kΩ or higher
      LH-3 - Body ground Always 10 kΩ or higher
      LH-4 - Body ground Always 10 kΩ or higher
      LH-5 - Body ground Always 10 kΩ or higher
      LH-6 - Body ground Always 10 kΩ or higher
      LH-7 - Body ground Always 10 kΩ or higher
      LH-8 - Body ground Always 10 kΩ or higher

    NG: REPLACE STEERING PAD SWITCH CABLE 

    OK: REPLACE STEERING PAD SWITCH RH 

About FixVault