2004 Toyota PriusFACTORY OEM SERVICE PROCEDURE

Engine Coolant Temperature Sensor (1NZ-FXE): Replacement

  1. PRECAUTION (See  PRECAUTION  ) 
  2. REMOVE RADIATOR SUPPORT OPENING COVER (See  REPLACEMENT   ) 
  3. REMOVE ENGINE UNDER COVER LH 
  4. REMOVE ENGINE UNDER COVER RH 
  5. DRAIN ENGINE COOLANT (See  REPLACEMENT  ) 
  6. DRAIN HV COOLANT (See  REPLACEMENT  ) 
  7. REMOVE REAR FLOOR BOARD NO.2 (See  REPLACEMENT  ) 
  8. REMOVE DECK FLOOR BOX REAR (See  REPLACEMENT  ) 
  9. REMOVE REAR FLOOR BOARD NO.3 (See  REPLACEMENT  ) 
  10. DISCONNECT ENGINE WIRE NO.3 (BATTERY NEGATIVE TERMINAL) (See  REPLACEMENT  ) 
  11. REMOVE SERVICE PLUG GRIP (See  HYBRID CONTROL SYSTEM  ) 
  12. REMOVE WINDSHIELD WIPER ARM COVER 
  13. REMOVE FR WIPER ARM RH (See  WIPER & WASHER  ) 
  14. REMOVE FR WIPER ARM LH (See  WIPER & WASHER  ) 
  15. REMOVE HOOD TO COWL TOP SEAL (See  WIPER & WASHER  ) 
  16. REMOVE COWL TOP VENTILATOR LOUVER LH (See  WIPER & WASHER  ) 
  17. REMOVE COWL TOP VENTILATOR LOUVER RH (See  WIPER & WASHER  ) 
  18. REMOVE WINDSHIELD WIPER LINK ASSY (See  WIPER & WASHER  ) 
  19. REMOVE COWL TOP PANEL SUB-ASSY OUTER FRONT (See  WINDSHIELD WIPER MOTOR ASSY  ) 
  20. REMOVE INVERTER COVER (See  HYBRID CONTROL SYSTEM  ) 
  21. VERIFY THAT VOLTAGE OF W/CONVERTER INVERTER ASSY IS 0V (See  HYBRID CONTROL SYSTEM  ) 
  22. DISCONNECT INVERTER COOLING HOSE NO.2 (See  HYBRID CONTROL SYSTEM  ) 
  23. DISCONNECT INVERTER COOLING HOSE NO.1 (See  HYBRID CONTROL SYSTEM  ) 
  24. DISCONNECT INVERTER COOLING HOSE NO.6 (See  HYBRID CONTROL SYSTEM  ) 
  25. REMOVE CIRCUIT BREAKER SENSOR NO.1 (See  HYBRID CONTROL SYSTEM  ) 
  26. DISCONNECT FRAME WIRE NO.2 (See  HYBRID CONTROL SYSTEM  ) 
  27. REMOVE W/CONVERTER INVERTER ASSY (See  HYBRID CONTROL SYSTEM  ) 
  28. REMOVE ENGINE COOLANT TEMPERATURE SENSOR 
    1. Disconnect the engine coolant temperature sensor connector.
    2. Using a deep socket wrench 19 mm, remove the engine coolant temperature sensor and gasket.
    Fig 1: Removing Engine Coolant Temperature Sensor
    G02920019Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  29. INSTALL ENGINE COOLANT TEMPERATURE SENSOR 
    1. Using a deep socket wrench 19 mm, install a new gasket and the engine coolant temperature sensor.
      1. Torque: 20 N.m (200 kgf.cm, 14 ft.lbf) 
    2. Connect the engine coolant temperature sensor connector.
    Fig 2: Installing Engine Coolant Temperature Sensor
    G02920020Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  30. INSTALL W/CONVERTER INVERTER ASSY (See  HYBRID CONTROL SYSTEM  ) 
  31. CONNECT FRAME WIRE NO.2 (See  HYBRID CONTROL SYSTEM  ) 
  32. INSTALL CIRCUIT BREAKER SENSOR NO.1 (See  HYBRID CONTROL SYSTEM  ) 
  33. CONNECT INVERTER COOLING HOSE NO.6 
  34. CONNECT INVERTER COOLING HOSE NO.1 
  35. CONNECT INVERTER COOLING HOSE NO.2 
  36. INSTALL INVERTER COVER (See  HYBRID CONTROL SYSTEM  ) 
  37. INSTALL COWL TOP PANEL SUB-ASSY OUTER FRONT (See  WINDSHIELD WIPER MOTOR ASSY  ) 
  38. INSTALL WINDSHIELD WIPER LINK ASSY (See  WIPER & WASHER  ) 
  39. INSTALL SERVICE PLUG GRIP (See  HYBRID CONTROL SYSTEM  ) 
  40. CONNECT ENGINE WIRE NO.3 (BATTERY NEGATIVE TERMINAL) (See  REPLACEMENT  ) 
  41. ADD ENGINE COOLANT (See  REPLACEMENT  ) 
  42. ADD HV COOLANT (See  REPLACEMENT  ) 
  43. CHECK FOR ENGINE COOLANT LEAKS (See  ON-VEHICLE INSPECTION  ) 
  44. CHECK FOR HV COOLANT LEAKS 
  45. INSTALL COWL TOP VENTILATOR LOUVER RH 
  46. INSTALL COWL TOP VENTILATOR LOUVER LH 
  47. INSTALL HOOD TO COWL TOP SEAL 
  48. INSTALL FR WIPER ARM LH (See  WIPER & WASHER  ) 
  49. INSTALL FR WIPER ARM RH (See  WIPER & WASHER  ) 
  50. INSTALL WINDSHIELD WIPER ARM COVER 
  51. INSTALL REAR FLOOR BOARD NO.3 
  52. INSTALL DECK FLOOR BOX REAR 
  53. INSTALL REAR FLOOR BOARD NO.2 
  54. INSTALL ENGINE UNDER COVER RH 
  55. INSTALL ENGINE UNDER COVER LH 
  56. INSTALL RADIATOR SUPPORT OPENING COVER 
  57. POWER WINDOW CONTROL SYSTEM INITIALIZE (See  INTRODUCTION  ) 
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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