LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2023 >> LX 600 Premium >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (W/O Canister Pump Module) - Diagnostic Codes (3 Of 5) >> SFI SYSTEM (w/o Canister Pump Module) >> DTC P023A-13: Charge Air Cooler Coolant Pump Control Circuit Open [12/2021 - ] >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC P023A-13: Charge Air Cooler Coolant Pump Control Circuit Open [12/2021 - ]: Procedure

  1. PERFORM ACTIVE TEST USING GTS (CONTROL THE INTERCOOLER WATER PUMP) 
    1. Perform the Active Test. Check that the electric water pump assembly is operating (vibrating).

      Powertrain > Engine > Active Test 

      Tester Display
      Control the Intercooler Water Pump

      OK

      The electric water pump assembly is operating (vibrating).

      HINT: 

      Use a sound scope if the operation is difficult to check.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  4

    Result: 

    OK 

    See step  2

  2. CHECK ECM (IWPI VOLTAGE) 

    Pre-procedure1

    1. Disconnect the electric water pump assembly connector.
    2. Turn the ignition switch to ON.

      Procedure1

    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      B29-2 (NWP) - Body ground Ignition switch ON 11 to 14 V

      Result

      Proceed to
      OK
      NG

      Post-procedure1

    4. None

    Result: 

    OK 

    REPLACE ELECTRIC WATER PUMP ASSEMBLY. Refer to  REMOVAL [12/2021 - ] 

    Result: 

    NG 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (ELECTRIC WATER PUMP ASSEMBLY - ECM) 

    Pre-procedure1

    1. Disconnect the electric water pump assembly connector.
    2. Disconnect the ECM connector.

      Procedure1

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      B29-2 (NWP) - B70-38 (IWPI) Always Below 1 Ω
      B29-2 (NWP) or B70-38 (IWPI) - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

      Post-procedure1

    4. None

    Result: 

    OK 

    REPLACE ECM. Refer to  REMOVAL [12/2021 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  4. CHECK HARNESS AND CONNECTOR (ELECTRIC WATER PUMP ASSEMBLY - BODY GROUND) 

    Pre-procedure1

    1. Disconnect the electric water pump assembly connector.

      Procedure1

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      B29-1 (PGND) - Body ground Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

      Post-procedure1

    3. None

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  5

  5. INSPECT EFI MAIN NO. 3 RELAY 

    Refer to ON-VEHICLE INSPECTION [12/2021 - ]

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    REPLACE EFI MAIN NO. 3 RELAY 

    Result: 

    OK 

    See step  6

  6. CHECK TERMINAL VOLTAGE (POWER SOURCE OF ELECTRIC WATER PUMP ASSEMBLY) 

    Pre-procedure1

    1. Disconnect the electric water pump assembly connector.
    2. Turn the ignition switch to ON.

      Procedure1

    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      B29-4 (+B) - Body ground Ignition switch ON 11 to 14 V

      Result

      Proceed to
      OK
      NG

      Post-procedure1

    4. None

    Result: 

    OK 

    REPLACE ELECTRIC WATER PUMP ASSEMBLY. Refer to  REMOVAL [12/2021 - ] 

    Result: 

    NG 

    See step  7

  7. CHECK HARNESS AND CONNECTOR (POWER SOURCE OF EFI MAIN NO. 3 RELAY) 

    Pre-procedure1

    1. Remove the EFI MAIN NO. 3 relay from the No. 2 engine room relay block and junction block assembly.
      GTY1074431Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 No. 2 Engine Room Relay Block and Junction Block Assembly
      *2 EFI MAIN NO. 3 Relay

      Procedure1

    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

      Post-procedure1

    3. None

    Result: 

    NG 

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

    Result: 

    OK 

    See step  8

  8. CHECK HARNESS AND CONNECTOR (EFI MAIN NO. 3 RELAY - BODY GROUND) 

    Pre-procedure1

    1. Remove the EFI MAIN NO. 3 relay from the No. 2 engine room relay block and junction block assembly.

      Procedure1

    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

      Post-procedure1

    3. None

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  9

  9. CHECK HARNESS AND CONNECTOR (EFI MAIN NO. 3 RELAY - ELECTRIC WATER PUMP ASSEMBLY) 

    Pre-procedure1

    1. Remove the EFI MAIN NO. 3 relay from the No. 2 engine room relay block and junction block assembly.
    2. Disconnect the electric water pump assembly connector.

      Procedure1

    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) - B29-4 (+B) Always Below 1 Ω
      5 (EFI MAIN NO. 3 relay) or B29-4 (+B) - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

      Post-procedure1

    4. None

    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 

scientia non olet · About LEMON Manuals