LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2003 >> LS 430 >> Repair and Diagnosis >> External Pages >> Different car >> Section 909 (Lighting System - Diagnostics) >> Automatic Light Control System Does Not Operate >> 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 4Runner. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK LIGHT 
    1. Check that headlamp and taillight light up.
    1. NG: FLOW CHART (GO TO FLOW CHART OF HEADLIGHT OR TAILLIGHT) 

    OK: Go to next step. 

  2. INSPECT HEADLAMP DIMMER SWITCH ASSY 
    1. Inspect light control switch continuity.
      1. Check that there is a continuity between terminals at each switch position as shown in the chart.

        Standard: 

        TESTER CONNECTION SPECIFIED CONDITION (1 OF 2)

        Switch operation Tester connection Specified condition
        OFF - No continuity
        TAIL 14 - 16 Continuity
        HEAD 13 - 16 - 14 Continuity
        AUTO 16 - 12 Continuity
        Fig 1: Identifying Connector Terminal (Headlamp Dimmer Switch Assy)
        G02577365Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: REPLACE HEADLAMP DIMMER SWITCH ASSY 

    OK: Go to next step. 

  3. CHECK AUTOMATIC LIGHT CONTROL SENSOR 
    1. Measure voltage between terminals as shown in the chart below.
    2. Check the continuity between terminal 3 (CLTE) and body ground as shown in the chart below.
    3. Using an oscilloscope, check that signal waveform appears between terminals.
      Fig 2: Identifying Connector Terminal (Automatic Light Control Sensor)
      G02577366Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard: 

      TESTER CONNECTION SPECIFIED CONDITION (2 OF 2)

      Terminal No. (Symbol) Tester connection Condition Specified condition
      1 (CLTB) 1 - 3 Constant 10-14 V
      3 (CLTE) 3 - Body ground Constant Continuity
      4 (CLTS) 4 - 3 IG SW ON Dimmer SW AUTO Signal waveform appears depending on outside brightness
    1. NG: REPLACE AUTOMATIC LIGHT CONTROL SENSOR 

    OK: Go to next step. 

  4. CHECK HARNESS AND CONNECTOR (BETWEEN MULTIPLEX NETWORK BODY ECU AND AUTOMATIC LIGHT CONTROL SENSOR) 
    1. Check that signal waveform appears between terminals B6-4 (CLTS) and B6-21 (CLTE) of the multiplex network body ECU.

      Standard: Bar appears 

    2. Measure voltage between terminals B6-6 (CLTB) and B6-21 (CLTE) of the multiplex network body ECU.

      Standard: 10-14 V 

    3. Check the continuity between terminal B6-21 (CLTE) of the multiplex network body ECU and body ground.

      Standard: There is continuity 

    1. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step. 

    CHECK AND REPLACE MULTIPLEX NETWORK BODY ECU 

scientia non olet · About LEMON Manuals