LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2004 >> ES 330 >> Repair and Diagnosis >> External Pages >> Different car >> Section 311 (Navigation System - Diagnostics) >> Navigation System >> Dimmer Signal Circuit >> Inspection Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Inspection Procedure

WARNING: This page is about a different car, the 2005 Toyota Sienna. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: The vehicle is equipped with SRS (Supplemental Restraint System) such as the airbags. Before servicing (including removal or installation of parts), be sure to read the precautionary notice for the SUPPLEMENTAL RESTRAINT SYSTEM .
  1. CHECK ILLUMINATION 
    1. Check if the illumination for the radio and navigation assy, steering pad switch assy, accessory meter or others (hazard SW, TRAC off SW, etc.) comes on when the light control switch is turned to the HEAD or TAIL position.

    Result: 

    ILLUMINATION RESULT

    Result Proceed to
    Illumination comes on for all components except steering pad switch. A
    Illumination comes on for all components except radio and navigation assy. B
    No illumination comes on (radio and navigation assy, rear A/C control SW, A/T shift level illumination, accessory meter, etc.) C
    Illumination comes on only for steering pad switch. D
    1. B: GO TO STEP   6 
    2. C: GO TO LIGHTING SYSTEM (SEE  PROBLEM SYMPTOMS TABLE  ) 
    3. D: GO TO COMBINATION METER SYSTEM (SEE  PROBLEM SYMPTOMS TABLE  ) 
    4. A: GO TO NEXT STEP 
  2. INSPECT SPIRAL CABLE SUB-ASSY (ILL+) 
    1. Disconnect the spiral cable sub-assy connector.
    2. Measure the voltage according to the value(s) in SPIRAL CABLE SUB-ASSY (ILL+) VOLTAGE .

      Standard: 

    SPIRAL CABLE SUB-ASSY (ILL+) VOLTAGE

    Tester connection Condition Specified condition
    ILL+ - Body ground Light control SW TAIL or HEAD 10 to 14 V
    Fig 1: Inspecting Spiral Cable Sub-Assy (ILL+)
    G02630305Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 
    2. OK: GO TO NEXT STEP 
  3. INSPECT STEERING PAD SWITCH ASSY 
    Fig 2: Inspecting Steering Pad Switch Assy
    G02630306Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the steering pad switch assy connector.
    2. Connect the positive (+) lead to terminal ILL+ and the negative (-) lead to terminal EAU of the steering pad switch assy connector.
    3. Check if the illumination for the steering pad switch assy comes on

      OK: 

      Illumination for the steering pad switch assy comes on. 

    1. NG: REPLACE STEERING PAD SWITCH LH (SEE  STEERING PAD SWITCH LH  ) 
    2. OK: GO TO NEXT STEP 
  4. INSPECT SPIRAL CABLE SUB-ASSY 
    1. Disconnect the steering pad switch assy and spiral cable sub-assy connectors.
    2. Measure the resistance according to the value(s) in SPIRAL CABLE SUB ASSY CONNECTOR FRONT VIEW .

      Standard: 

    SPIRAL CABLE SUB ASSY CONNECTOR FRONT VIEW

    Tester connection Specified condition
    EAU - EAU Below 1 Ω
    ILL+ - ILL+ Below 1 Ω
    Fig 3: Inspecting Spiral Cable Sub-Assy
    G02630307Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: REPLACE  SPIRAL CABLE SUB-ASSY 
    2. OK: GO TO NEXT STEP 
  5. CHECK HARNESS AND CONNECTOR (SPIRAL CABLE SUB-ASSY - RADIO AND NAVIGATION ASSY) 
    1. Disconnect the connectors from the radio and navigation assy and spiral cable sub-assy.
    2. Measure the resistance according to the value(s) in SPIRAL CABLE SUB-ASSY - RADIO AND NAVIGATION ASSY RESISTANCE .

      Standard: 

    SPIRAL CABLE SUB-ASSY - RADIO AND NAVIGATION ASSY RESISTANCE

    Tester connector Condition Specified condition
    SWG - EAU Always Below 1 Ω
    SWG-Body ground Always 10 kΩ or higher
    Fig 4: Disconnecting Connectors From Radio & Navigation Assy Connector R13
    G02630308Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    Fig 5: Spiral Cable Sub Assy Connector Front View
    G02630309Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 
    2. OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN  PROBLEM SYMPTOMS TABLE  
  6. INSPECT RADIO AND NAVIGATION ASSY (ILL+) 
    1. Disconnect the radio and navigation assy connector R15.
    2. Measure the voltage according to the value(s) in RADIO AND NAVIGATION ASSY (ILL+) .

      Standard: 

    RADIO AND NAVIGATION ASSY (ILL+)

    Tester connection Condition Specified condition
    ILL+-Body ground Light control switch TAIL or HEAD 10 to 14 V
    Fig 6: Disconnecting Radio & Navigation Assy Connector R15
    G02630310Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 
    2. OK: GO TO NEXT STEP 
  7. CHECK HARNESS AND CONNECTOR (RADIO AND NAVIGATION ASSY - COMBINATION METER ASSY) 
    1. Disconnect the radio and navigation assy connector R15 and combination meter assy connector C10.
    2. Measure the resistance according to the value(s) in RADIO AND NAVIGATION ASSY - COMBINATION METER ASSY RESISTANCE .

      Standard: 

    RADIO AND NAVIGATION ASSY - COMBINATION METER ASSY RESISTANCE

    Tester connector Condition Specified condition
    ILL- - C10-25 Always Below 1 Ω
    ILL--Body ground Always 10 kΩ or higher
    Fig 7: Disconnecting Radio & Navigation Assy Connector R15
    G02630311Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    Fig 8: Disconnecting Combination Meter Assy Connector C10
    G02630312Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 
    2. OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN  PROBLEM SYMPTOMS TABLE  
scientia non olet · About LEMON Manuals