Toyota Previa 1991-1997 Repair Information

Volume Airflow Meter

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OPERATION



The 2TZ-FE engine utilizes a Volume Air Flow Meter (VAF) contains a spring-loaded measuring plate. The plate is connected to a potentiometer which controls the signal to the ECM. In this way, the control unit is advised of intake air volume and can control injector duration and ignition advance accordingly.

TESTING



See Figures 1 through 4

  1. To test the VAF meter on the vehicle, disconnect the meter wiring.
    1. Using an ohmmeter, measure the resistance between each terminal.
    2.  
    3. If the resistance is not within specifications, replace the VAF meter.
    4.  
    5. Reconnect the harness to the VAF meter.

      Click image to see an enlarged view

      Fig. Fig. 1: Use the ohmmeter to test between each of the terminals on the VAF meter-2TZ-FE engine



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      Fig. Fig. 2: On-vehicle VAF meter resistance values-2TZ-FE engine

    6.  

  2.  
  3. Testing the meter off the vehicle perform the following:
    1. Using an ohmmeter, measure the resistance between each terminal by moving the measuring plate.
    2.  
    3. The resistance between terminals E2 and VS will change in a wave pattern as the measuring plate slowly opens.
    4.  
    5. If the resistance is not as specified, replace the VAF meter.

      Click image to see an enlarged view

      Fig. Fig. 3: Measure the resistance between each terminal by moving the measuring plate of the VAF meter



      Click image to see an enlarged view

      Fig. Fig. 4: Off-vehicle VAF meter resistance values-2TZ-FE engine

    6.  

  4.  

REMOVAL & INSTALLATION



See Figures 5 and 6

  1. Disconnect the VAF meter wiring.
  2.  



Click image to see an enlarged view

Fig. Fig. 5: The Volume Airflow Meter is attached to the air cleaner cap-2TZ-FE engine

  1. Disconnect the air intake temperature sensor wiring.
  2.  
  3. Remove the air cleaner cap and VAF meter as an assembly.
  4.  
  5. To separate the two components, pry off the lock plate, remove the 4 nuts and washers, lock plate, VAF meter and gasket.
  6.  
  7. Installation is the reverse of removal.
  8.  



Click image to see an enlarged view

Fig. Fig. 6: Pry off the lock plate on the VAF meter first when separating the two components

 
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