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Home >> Lexus >> 2021 >> LS 500 Base, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Diagnostic Codes (11 Of 14) >> SFI System >> DTC P1660-14: Air Intake Control Valve Circuit Short to Ground or Open [12/2017 - 10/2020] >> Procedure

DTC P1660-14: Air Intake Control Valve Circuit Short to Ground or Open [12/2017 - 10/2020]: Procedure

  1. PERFORM ACTIVE TEST USING TECHSTREAM (ACTIVATE THE VSV FOR AICS) 
    GTY521464Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    *1 Air
    *2 Port E
    *3 Port F
    *4 Air Filter
    *a Vacuum Switching Valve is On
    *b Vacuum Switching Valve is Off
    1. Disconnect the vacuum hose (port F) from the vacuum switching valve assembly (for AICV).
    2. Connect the Techstream to the DLC3.
    3. Turn the engine switch on (IG).
    4. Turn the Techstream on.
    5. Enter the following menus: Powertrain / Engine / Active Test / Activate the VSV for AICS.

      Powertrain > Engine > Active Test 

      Tester Display
      Activate the VSV for AICS
    6. Check the operation of the vacuum switching valve assembly (for AICV) when the vacuum switching valve assembly (for AICV) is operated using the Techstream.

      Standard

      Techstream Connection Specified Condition
      ON Air from port E flows out through port F
      OFF Air from port E flows out through the air filter

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    CHECK FOR INTERMITTENT PROBLEMS. Refer to  CHECK FOR INTERMITTENT PROBLEMS [12/2017 - ] 

    Result: 

    NG 

    See step  2

  2. INSPECT VACUUM SWITCHING VALVE ASSEMBLY (FOR AICV) 
    1. Inspect the vacuum switching valve assembly (for AICV)

      Refer to PROCEDURE - Step 4

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE VACUUM SWITCHING VALVE ASSEMBLY (FOR AICV) 

    Result: 

    OK 

    See step  3

  3. CHECK TERMINAL VOLTAGE (POWER SOURCE OF VACUUM SWITCHING VALVE ASSEMBLY (FOR AICV)) 
    1. Disconnect the vacuum switching valve assembly (for AICV) connector.
    2. Turn the engine switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      D27-2 (+B) - Body ground Engine switch on (IG) 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  5

    Result: 

    OK 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (VACUUM SWITCHING VALVE ASSEMBLY (FOR AICV) - ECM) 
    1. Disconnect the vacuum switching valve assembly (for AICV) 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
      D27-1 (AIRV) - D1-41 (AICV) Always Below 1 Ω
      D27-1 (AIRV) or D1-41 (AICV) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

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

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  5. INSPECT EFI-MAIN NO. 3 RELAY 
    1. Inspect the EFI-MAIN NO. 3 relay.

      Refer to ON-VEHICLE INSPECTION [12/2017 - 10/2023]

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE EFI-MAIN NO. 3 RELAY 

    Result: 

    OK 

    See step  6

  6. CHECK HARNESS AND CONNECTOR (POWER SOURCE OF EFI-MAIN NO. 3 RELAY) 
    GTY797631Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    *1 Engine Room Relay Block and Junction Block Assembly
    *2 EFI-MAIN NO. 3 Relay
    1. Remove the EFI-MAIN NO. 3 relay from the engine room relay block and junction block assembly.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      3 (EFI-MAIN NO. 3 relay) - Body ground Always 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - EFI-MAIN NO. 3 RELAY) 

    Result: 

    OK 

    See step  7

  7. CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 3 RELAY - BODY GROUND) 
    1. Remove the EFI-MAIN NO. 3 relay from the engine room relay block and junction block assembly.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      1 (EFI-MAIN NO. 3 relay) - Body ground Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  8

  8. CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 3 RELAY - VACUUM SWITCHING VALVE ASSEMBLY (FOR AICV)) 
    1. Remove the EFI-MAIN NO. 3 relay from the No. 1 engine room relay block and junction block assembly.

      HINT: 

      Remove the A/F HTR relay, VVT NO. 1 relay and VVT NO. 2 relay connected between the checked terminals as the coil inside the relay influences the measurement value.

    2. Disconnect the vacuum switching valve assembly (for AICV) connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      5 (EFI-MAIN NO. 3 relay) - D27-2 (+B) Always Below 1 Ω
      5 (EFI-MAIN NO. 3 relay) or D27-2 (+B) - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI-MAIN NO. 1 RELAY - EFI-MAIN NO. 3 RELAY) 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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