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DTC P26CA-31: Engine Coolant Pump No Signal [10/2022 - 11/2023]: Procedure

WARNING: This page is about a different variant/trim than selected.
  1. CHECK TERMINAL VOLTAGE (POWER SOURCE OF WATER INLET HOUSING WITH WATER PUMP SUB-ASSEMBLY) 
    GTY941697Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    *a Front view of wire harness connector
    (to Water Inlet Housing with Water Pump Sub-assembly)
    1. Disconnect the water inlet housing with water pump sub-assembly connector.
    2. Turn the ignition switch to ON.
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      C39-5 (NWP) - Body ground Ignition switch ON 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  8

    Result: 

    OK 

    See step  2

  2. CHECK HARNESS AND CONNECTOR (WATER INLET HOUSING WITH WATER PUMP SUB-ASSEMBLY - BODY GROUND) 
    1. Disconnect the water inlet housing with water pump sub-assembly connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      C39-3 (PGN2) - Body ground Always Below 1 Ω
      C39-6 (PGND) - Body ground Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  3

  3. CHECK TERMINAL VOLTAGE (POWER SOURCE OF WATER INLET HOUSING WITH WATER PUMP SUB-ASSEMBLY) 
    GTY908568Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    *a Front view of wire harness connector
    (to Water Inlet Housing with Water Pump Sub-assembly)
    1. Disconnect the water inlet housing with water pump sub-assembly connector.
    2. Turn the ignition switch to ON.
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      C39-1 (+B2) - Body ground Ignition switch ON 11 to 14 V
      C39-4 (+B) - Body ground Ignition switch ON 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE WATER INLET HOUSING WITH WATER PUMP SUB-ASSEMBLY 

    Refer to REMOVAL [12/2019 - ]

    Result: 

    NG 

    See step  4

  4. INSPECT EFI-MAIN NO. 3 RELAY 

    Refer to PROCEDURE - Step 3

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    REPLACE EFI-MAIN NO. 3 RELAY 

    Result: 

    OK 

    See step  5

  5. CHECK HARNESS AND CONNECTOR (POWER SOURCE OF EFI-MAIN NO. 3 RELAY) 
    GTY922624Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
    *2 EFI-MAIN NO. 3 Relay
    1. Remove the EFI-MAIN NO. 3 relay from the No. 1 engine room relay block and No. 1 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 (AUXILIARY BATTERY - EFI-MAIN NO. 3 RELAY) 

    Result: 

    OK 

    See step  6

  6. CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 3 RELAY - BODY GROUND) 
    1. Remove the EFI-MAIN NO. 3 relay from the No. 1 engine room relay block and No. 1 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  7

  7. CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 3 RELAY - WATER INLET HOUSING WITH WATER PUMP SUB-ASSEMBLY) 
    1. Remove the EFI-MAIN NO. 3 relay from the No. 1 engine room relay block and No. 1 junction block assembly.
    2. Disconnect the water inlet housing with water pump sub-assembly 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) - C39-1 (+B2) Always Below 1 Ω
      5 (EFI-MAIN NO. 3 relay) - C39-4 (+B) Always Below 1 Ω
      5 (EFI-MAIN NO. 3 relay), C39-1 (+B2) or C39-4 (+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 

  8. CHECK HARNESS AND CONNECTOR (WATER INLET HOUSING WITH WATER PUMP SUB-ASSEMBLY - ECM) 
    1. Disconnect the water inlet housing with water pump sub-assembly 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
      C39-5 (NWP) - C55-51 (WPI) Always Below 1 Ω
      C39-5 (NWP) or C55-51 (WPI) - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE ECM 

    Refer to REMOVAL [10/2022 - 11/2023]

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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