2004 Toyota PriusFACTORY OEM SERVICE PROCEDURE

Knock Sensor (1NZ-FXE): Replacement

  1. REMOVE RADIATOR SUPPORT OPENING COVER (See  REPLACEMENT   ) 
  2. REMOVE ENGINE UNDER COVER LH 
  3. DRAIN ENGINE COOLANT (See  REPLACEMENT  ) 
  4. REMOVE REAR FLOOR BOARD NO.2 (See  REPLACEMENT  ) 
  5. REMOVE DECK FLOOR BOX REAR (See  REPLACEMENT  ) 
  6. REMOVE REAR FLOOR BOARD NO.3 (See  REPLACEMENT  ) 
  7. DISCONNECT ENGINE WIRE NO.3 (BATTERY NEGATIVE TERMINAL) (See  REPLACEMENT  ) 
  8. REMOVE AIR CLEANER ASSY (See  REPLACEMENT   ) 
  9. REMOVE OIL LEVEL GAUGE GUIDE 
    1. Remove the oil level gauge from the oil level gauge guide.
    2. Remove the wire harness clamp.
    3. Remove the bolt, then pull out the oil level gauge guide.
    Fig 1: Locating Oil Level Gauge, Wire Harness Clamp & Oil Level Gauge Guide
    G02920033Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  10. REMOVE INTAKE MANIFOLD 
    1. Disconnect the ventilation hose from the throttle with motor body.
    2. Disconnect the ventilation hose No. 2 from the throttle with motor body.
    3. Disconnect the fuel vapor feed hose No. 1 from the throttle with motor body.
      Fig 2: Locating Ventilation Hose, Hose No.2 & Full Vapor Feed Hose No.1 From Throttle With Motor Body
      G02920034Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    4. Disconnect the water by-pass hose from the throttle with motor body.
    5. Disconnect the water by- pass hose No. 2 from the throttle with motor body.
      Fig 3: Locating Water By-Pass Hose, Hose No.2 From Throttle With Motor Body
      G02920035Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    6. Disconnect the throttle control motor connector.
    7. Disconnect the throttle position sensor connector.
      Fig 4: Locating Throttle Control Motor Connector & Throttle Position Sensor Connector
      G02920036Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    8. Remove the 3 wire harness clamps.
    9. Remove the connector clamp.
    10. Remove the bolt, then remove the harness clamp bracket.
      Fig 5: Locating Wire Harness Clamp, Connector Clamp, Bolt Of Harness Clamp Bracket
      G02920037Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    11. Remove the fuel vapor feed hose No. 1 from the hose clamp.
    12. Remove the 3 bolts and 2 nuts, then remove the intake manifold.
      Fig 6: Locating Full Vapor Feed Hose No.1 Of Hose Clamp & Bolts, Nuts Of Intake Manifold
      G02920038Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    13. Remove the gasket from the cylinder head.
      Fig 7: Locating Gasket Of Cylinder Head
      G02920039Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  11. REMOVE KNOCK SENSOR 
    1. Disconnect the knock sensor connector.
    2. Remove the nut, then remove the knock sensor.
    Fig 8: Locating Knock Sensor Connector & Nut Of Knock Sensor
    G02920040Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  12. INSTALL KNOCK SENSOR 
    1. Install the knock sensor with the nut.
      1. Torque: 20 N.m (204 kgf.cm, 15 ft.lbf) 
      NOTE: Be careful to install the knock sensor in the correct direction.
    2. Connect the knock sensor connector.
    Fig 9: Identifying Knock Sensor Correct Directions
    G02920041Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  13. INSTALL INTAKE MANIFOLD 
    1. Install a new gasket to the cylinder head.
    2. Install the intake manifold with the 3 bolts and 2 nuts.
      1. Torque: 20 N.m (204 kgf.cm, 15 ft.lbf) 
    3. Install the fuel vapor feed hose No. 1 to the hose clamp.
    4. Install the harness clamp bracket with the bolt.
      1. Torque: 9.0 N.m (92 kgf.cm, 80 in.lbf) 
    5. Install the connector clamp.
    6. Install the 3 wire harness clamps.
    7. Connect the throttle position sensor connector.
    8. Connect the throttle control motor connector.
    9. Connect the water by-pass hose No. 2 to the throttle with motor body.
    10. Connect the water by-pass hose to the throttle with motor body.
    11. Connect the fuel vapor feed hose No. 1 to the throttle with motor body.
    12. Connect the ventilation hose No. 2 to the throttle with motor body.
    13. Connect the ventilation hose to the throttle with motor body.
  14. INSTALL OIL LEVEL GAUGE GUIDE 
    1. Apply a light coat of engine oil to a new O-ring, then install it to the oil level gauge guide.
    2. Apply a light coat of engine oil to the O-ring again, then install the oil level gauge guide with the bolt.
      1. Torque: 9.0 N.m (92 kgf.cm, 80 in.lbf) 
      NOTE: Be careful that the O-ring is not cracked or jammed when installing.
    3. Install the wire harness clamp.
    4. Install the oil level gauge to the oil level gauge guide.
    Fig 10: Identifying New O-Ring Position
    G02920042Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  15. INSTALL AIR CLEANER ASSY (See  REPLACEMENT   ) 
  16. CONNECT ENGINE WIRE NO.3 (BATTERY NEGATIVE TERMINAL) (See  REPLACEMENT  ) 
  17. ADD ENGINE COOLANT (See  REPLACEMENT  ) 
  18. CHECK FOR ENGINE COOLANT LEAKS (See  REPLACEMENT  ) 
  19. CHECK FOR ENGINE OIL LEAKS 
  20. INSTALL REAR FLOOR BOARD NO.3 
  21. INSTALL DECK FLOOR BOX REAR 
  22. INSTALL REAR FLOOR BOARD NO.2 
  23. INSTALL ENGINE UNDER COVER LH 
  24. INSTALL RADIATOR SUPPORT OPENING COVER 
  25. POWER WINDOW CONTROL SYSTEM INITIALIZE (See  INTRODUCTION  ) 
Factory Service Tools

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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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