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Inspection Procedure

WARNING: This page is about a different car, the 2008 Lexus RX 350. However, it is still accessible from the selected car via links, so may be relevant.
  1. INSPECT HEADLIGHT BEAM LEVEL CONTROL ECU 
    1. Measure the voltage according to the value(s) in the table below.
      Fig 1: Identifying H17 Headlight Beam Level Control ECU Connector Terminals
      G05273858Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Voltage 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester connection Condition Specified Condition
      H17-7 (HDLP) - H17-1 (GND) Light Control switch OFF → HEAD 10 to 14 V → Below 1 V

    NG: Go to step  4

    OK: Go to Next step 

  2. INSPECT HEADLIGHT BEAM LEVEL CONTROL ECU 
    1. Measure the voltage according to the value(s) in the table below.
      Fig 2: Identifying H17 Headlight Beam Level Control ECU Connector Terminals
      G05273859Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Voltage 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester connection Condition Specified Condition
      H17-5 (SPDL) - H17-1 (GND) Drive at about 30 km/h (19 mph) 0 to 14 V Pulse generation (*1)
      H17-6 (SPDR) - H17-1 (GND) Drive at about 30 km/h (19 mph) 0 to 14 V Pulse generation (*1)
    2. *1: Oscilloscope wave

      HINT:

      • Gauge set: 5 V/DIV. 2 ms/DIV
      • Condition: Drive at about 30 km/h (19 mph)
      Fig 3: Identifying Oscilloscope Wave
      G05273860Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: Go to step  5

    OK: Go to Next step 

  3. INSPECT HEADLIGHT BEAM LEVEL CONTROL ECU 
    1. Measure the voltage according to the value(s) in the table below.
      Fig 4: Identifying H17 Headlight Beam Level Control ECU Connector Terminals
      G05273861Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Voltage 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester connection Condition Specified Condition
      H17-8 (CHG-) - H17-1 (GND) Engine is running 10 to 14 V

    NG: Go to step  6

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

  4. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL J/B - HEADLIGHT BEAM LEVEL CONTROL ECU) 
    1. Disconnect the 1D connector of instrument panel junction block assembly and the H17 connector of headlight beam level control ECU.
    2. Measure the resistance according to the value(s) in the table below.
      Fig 5: Disconnecting H17 Connector Of Headlight Beam Level Control ECU Connector Terminals
      G05273862Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Resistance 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester connection Condition Specified condition
      1D-3 - H17-7 Always Below 1 Ω
      Fig 6: Identifying 1D Instrument Panel Junction Block Assembly Front Side Connector Terminals
      G05273863Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK:  GO TO "HEADLIGHT RELAY CIRCUIT "

  5. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - HEADLIGHT BEAM LEVEL CONTROL ECU) 
    1. Disconnect the S1 connector of skid control ECU and the H17 connector of headlight beam level control ECU.
    2. Measure the resistance according to the value(s) in the table below.
      Fig 7: Identifying S1 Skid Control ECU And H17 Headlight Beam Level Control ECU Connector Terminals
      G05273864Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Resistance 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester connection Condition Specified condition
      S1 -39 (RRO) - H17-6 (SPDR) Always Below 1 Ω
      S1-40 (RLO) - H17-5 (SPDL) Always Below 1 Ω

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK:  GO TO appropriate FLOW CHART or PROBLEM SYMPTOMS TABLE .

  6. CHECK HARNESS AND CONNECTOR (GENERATOR ASSEMBLY - HEADLIGHT BEAM LEVEL CONTROL ECU) 
    1. Disconnect the G2 connector generator and the H17 connector of headlight beam level control ECU.
    2. Measure the resistance according to the value(s) in the table below.
      Fig 8: Identifying G2 Generator And H17 Headlight Beam Level Control ECU Connector Terminals
      G05273865Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Resistance 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester connection Condition Specified condition
      G2-4 (L) - H17-8 (CHG-) Always Below 1 Ω

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPAIR OR REPLACE GENERATOR ASSEMBLY 

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