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Home >> Lexus >> 2019 >> ES 350 Luxury >> Repair and Diagnosis >> External Pages >> Different car >> Section 147 (Engine Control System (A25A-FXS) - Diagnostic Codes (19 Of 20)) >> SFI System >> DTC P26CA-31: Engine Coolant Pump No Signal [08/2021 - ] >> Procedure

DTC P26CA-31: Engine Coolant Pump No Signal [08/2021 - ]: Procedure

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  1. CHECK TERMINAL VOLTAGE (POWER SOURCE OF WATER INLET HOUSING WITH WATER PUMP SUB-ASSEMBLY) 
    GTY833996Courtesy 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 power switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      C66-5 (NWP) - Body ground Power switch on (IG) 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
      C66-3 (PGN2) - Body ground Always Below 1 Ω
      C66-6 (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) 
    GTY805840Courtesy 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 power switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      C66-1 (+B2) - Body ground Power switch on (IG) 11 to 14 V
      C66-4 (+B) - Body ground Power switch on (IG) 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE WATER INLET HOUSING WITH WATER PUMP SUB-ASSEMBLY. Refer to  REMOVAL [06/2018 - ] 

    Result: 

    NG 

    See step  4

  4. INSPECT A/F HTR RELAY 
    1. Inspect the A/F HTR relay.

      Refer to PROCEDURE - Step 3

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE A/F HTR RELAY 

    Result: 

    OK 

    See step  5

  5. CHECK HARNESS AND CONNECTOR (POWER SOURCE OF A/F HTR RELAY) 
    GTY827065Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
    *2 A/F HTR Relay
    1. Remove the A/F HTR 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 (A/F HTR relay) - Body ground Always 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (AUXILIARY BATTERY - A/F HTR RELAY) 

    Result: 

    OK 

    See step  6

  6. CHECK HARNESS AND CONNECTOR (A/F HTR RELAY - BODY GROUND) 
    1. Remove the A/F HTR 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 (A/F HTR 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 (A/F HTR RELAY - WATER INLET HOUSING WITH WATER PUMP SUB-ASSEMBLY) 
    1. Remove the A/F HTR 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 (A/F HTR relay) - C66-1 (+B2) Always Below 1 Ω
      5 (A/F HTR relay) - C66-4 (+B) Always Below 1 Ω
      5 (A/F HTR relay), C66-1 (+B2) or C66-4 (+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 - A/F HTR 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
      C66-5 (NWP) - C88-51 (WPI) Always Below 1 Ω
      C66-5 (NWP) or C88-51 (WPI) - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE ECM. Refer to  REMOVAL [08/2021 - 09/2022]  , or refer to  REMOVAL [09/2022 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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