2004 Toyota Sienna CEFACTORY OEM SERVICE PROCEDURE

On-Vehicle Inspection

  1. INSPECTION THROTTLE BODY 
    1. Listen to the throttle control motor operating sound.
      1. Turn the ignition switch ON.
      2. When turning the accelerator pedal position sensor lever, check the running sound of the motor. Also, check that there is no friction noise.
    2. Inspect the throttle position sensor.
      1. Connect the hand-held tester or OBD II scan tool to the DLC3.
      2. Turn the ignition switch ON.
      3. Check that the MIL does not illuminate.
      4. Check that the throttle valve opening percentage (THROTTLE POS) in the DATA LIST snows the standard value.

      Standard throttle valve opening percentage: 60% or more 

  2. INSPECT ACCELERATOR PEDAL POSITION SENSOR 
    1. After turning ignition switch ON, check the DATA LIST and verify that the throttle position sensor voltage is within specifications.

    Standard voltage: 0.6 to 1.0 V 

  3. INSPECT CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY 
    1. Connect the hand-held tester or OBD II scan tool to the DLC3.
    2. Turn the ignition switch ON.
    3. Start the engine and let it warms up.
    4. Connect the hand-held tester and select the VVT from the ACTIVE TEST menu.
    5. Monitor the engine speed when the OCV is operated with the hand-held tester.

      Standard: 

      VVT system is OFF (OCV is OFF): Normal engine speed 

      VVT system is ON (OCV is ON): Rough idle or engine stalled 

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.