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Home >> Lexus >> 2022 >> LS 500 Base, AWD >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Control System - Diagnostic Codes (11 Of 14) >> SFI System >> DTC P16B3-18: Multi Flow Control Valve Motor Circuit Current Below Threshold; DTC P16B3-19: Multi Flow Control Valve Motor Circuit Current Above Threshold [12/2017 - ] >> Procedure
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DTC P16B3-18: Multi Flow Control Valve Motor Circuit Current Below Threshold; DTC P16B3-19: Multi Flow Control Valve Motor Circuit Current Above Threshold [12/2017 - ]: Procedure

  1. INSPECT WATER CONTROL VALVE 
    1. Inspect the water control valve.

      Refer to INSPECTION [12/2017 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE WATER CONTROL VALVE. Refer to  REMOVAL [12/2017 - 09/2018]  , or refer to  REMOVAL [09/2018 - 10/2020]  , or refer to  REMOVAL [10/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023]  , or refer to  REMOVAL [10/2023 - ] 

    Result: 

    OK 

    See step  2

  2. CHECK HARNESS AND CONNECTOR (WATER CONTROL VALVE - ECM) 
    1. Disconnect the water control valve connector.
    2. Disconnect the ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      D39-4 (FCM+) - D2-15 (FCM+) Always Below 1 Ω
      D39-5 (FCM-) - D2-16 (FCM-) Always Below 1 Ω
      D39-4 (FCM+) or D2-15 (FCM+) - Body ground and other terminals Always 10 kΩ or higher
      D39-5 (FCM-) or D2-16 (FCM-) - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  3

  3. INSPECT ECM (INTERNAL CIRCUIT) 
    GTY838247Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    *a Front view of wire harness connector
    (to Water Control Valve)
    *b Waveform of FCM+ terminal and FCM- terminal during fail-safe
    1. Disconnect the water control valve connector.
    2. Inspect the ECM using an oscilloscope.
    3. Turn the engine switch on (IG).
    4. Connect an oscilloscope between the terminals of the water control valve.
      ECM Terminal Name D39-4 (FCM+) - D39-5 (FCM-)
      Tester Range 2 V/DIV., 1 ms./DIV.
      Condition Engine switch on (IG)
    5. While the engine switch is on (IG), check the waveform between the FCM+ terminal and FCM- terminal during fail-safe.

      Standard

      25% duty waveform is output

      HINT: 

      • Check the operation circuit of the ECM by checking the waveform during fail-safe.
      • Because fail-safe is prohibited when the ambient temperature is 0°C (32°F) or less, work in a location where the ambient temperature is 5°C (41°F) or higher.
      • DTCs may be stored during this inspection. Check for DTCs and clear them using the Techstream.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE WATER CONTROL VALVE. Refer to  REMOVAL [12/2017 - 09/2018]  , or refer to  REMOVAL [09/2018 - 10/2020]  , or refer to  REMOVAL [10/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023]  , or refer to  REMOVAL [10/2023 - ] 

    Result: 

    NG 

    REPLACE ECM. Refer to  REMOVAL [12/2017 - 09/2018]  , or refer to  REMOVAL [09/2018 - 10/2020]  , or refer to  REMOVAL [10/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023]  , or refer to  REMOVAL [10/2023 - ]