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Home >> Lexus >> 2024 >> RX 500h >> Repair and Diagnosis >> External Pages >> Different car >> Section 104 (Engine Control System - Diagnostic Codes (P2270-P26CE)) >> SFI System >> DTC P26CB-71: Engine Coolant Pump Actuator Stuck [10/2022 - 08/2023] >> Procedure

DTC P26CB-71: Engine Coolant Pump Actuator Stuck [10/2022 - 08/2023]: Procedure

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  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P26CB-71) 
    1. Read the DTCs.

      Powertrain > Engine > Trouble Codes 

      Result

      Result Proceed to
      P26CB-71 and other DTCs are output A
      P26CB-71 and P26CE-37 are output B
      P26CB-71 is output C

      HINT: 

      If any DTCs other than P26CB-71 are output, troubleshoot those DTCs first.

    Result: 

    GO TO DTC CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [10/2022 - 08/2023] 

    Result: 

    See step  2

    Result: 

    See step  2

  2. CHECK ENGINE COOLANT LEVEL IN RESERVOIR TANK 
    1. Check that the engine coolant level is between the FULL and LOW lines.

      Refer to PROCEDURE - Step 2

      Result

      Result Proceed to
      Engine coolant level is above the LOW line A
      Engine coolant level is below the LOW line B

    Result: 

    See step  6

    Result: 

    See step  3

  3. CHECK FOR ENGINE COOLANT LEAKS 
    1. Check the areas around the engine and heater for engine coolant leaks.

      Refer to PROCEDURE - Step 1

      HINT: 

      If the engine oil is cloudy during the engine oil level dipstick check, it means that engine coolant has entered the engine lubrication system.

      OK

      No leaks.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  5

    Result: 

    OK 

    See step  4

  4. ADD ENGINE COOLANT 
    1. Fill the reservoir tank up to the FULL line with engine coolant.

      HINT: 

      Refer to PROCEDURE - Step 5

      NOTE:

      Make sure not to add engine coolant when the engine is hot.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  6

  5. REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA 
    1. Repair any engine coolant leaks.

      HINT: 

      Add engine coolant and perform air bleeding after repair.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  6

  6. PERFORM ACTIVE TEST USING GTS (ACTIVATE THE ELECTRIC WATER PUMP) 
    1. According to the display on the GTS, read the Data List while performing the Active Test.

      Powertrain > Engine > Active Test 

      Active Test Display
      Activate the Electric Water Pump
      Data List Display
      Electric Water Pump Speed

      Standard

      Active Test Operation Electric Water Pump Speed
      3000 rpm 2000 rpm or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    See step  8

    Result: 

    NG 

    See step  7

  7. INSPECT ECM (INTERNAL CIRCUIT) 

    Pre-procedure1

    • Disconnect the engine water pump assembly (water inlet housing) connector.
    • Perform the Active Test using the GTS.

      Powertrain > Engine > Active Test 

      Tester Display
      Activate the Electric Water Pump
    • Measure the resistance according to the value(s) in the table below.

      Standard

      Tester Connection Condition Specified Condition
      B77-2 (SWP) - Body ground During Active Test Resistance fluctuates*

      HINT: 

      • *: Using the Active Test, duty control of the transistors in the ECM will be performed. Due to the duty control, resistance of the SWP terminal will be unstable during the Active Test. If the resistance fluctuates while performing the Active Test, it can be determined that the transistor is operating. If the transistor does not operate during the Active Test, the ECM may be malfunctioning.

      Result

      Proceed to
      OK
      NG

    Post-procedure1

    • None.

    Result: 

    NG 

    REPLACE ECM. Refer to  REMOVAL [10/2022 - 08/2023] 

    Result: 

    OK 

    See step  8

  8. REPLACE ENGINE WATER PUMP ASSEMBLY (WATER INLET HOUSING) 

    HINT: 

    • Refer to REMOVAL [10/2022 - ]
    • When replacing any cooling system parts, if excessive deposits of rust or scale exist or the concentration of the engine coolant is abnormal, replace the engine coolant.

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  9

  9. CLEAR DTC 

    Pre-procedure1

    • None.
    • Clear the DTCs.

      Powertrain > Engine > Clear DTCs 

      Result

      Proceed to
      NEXT

    Post-procedure1

    • Turn the ignition switch off and wait for at least 30 seconds.

    Result: 

    NEXT 

    See step  10

  10. CHECK WHETHER DTC OUTPUT RECURS (DTC P26CB-71) 

    Pre-procedure1

    • Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    • Read the DTCs.

      Powertrain > Engine > Trouble Codes 

      HINT: 

      If no DTC is output, the repair has been successfully completed.

      Result

      Proceed to
      NEXT

    Post-procedure1

    • None.

    Result: 

    NEXT 

    END