Mass Air Flow Meter: Inspection

INSPECT OUTPUT VOLTAGE
1. Apply battery voltage across terminals 3 (+B) and 4 (E2G).
2. Connect the positive (+) tester probe to terminal 5 (VG), and the negative (-) tester probe to terminal 4 (E2G).
3. Blow air into the MAF meter, and check if the voltage fluctuates.
INSPECT RESISTANCE

Fig 1: Identifying Resistance & Temperature Graph
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
1. Using an ohmmeter, measure the resistance between terminals 2 (THA) and 1 (E2).
  Resistance:
  
  12.5 to 16.9 kΩ at -20°C (-4°F)
  
  2.19 to 2.67 kΩ at 20°C (68°F)
  
  0.50 to 0.68 kΩ at 60°C (140°F)
INSPECT MASS AIR FLOW METER
1. If using a intelligent tester:
  1. Connect the intelligent tester to the DLC3.
  2. Turn the ignition switch to the ON position.
  3. Blow air into the MAF meter, and check that the air flow value of the CURRENT DATA changes. If operation is not as specified, check the MAF meter as well as the wiring and the ECM.
2. If not using a intelligent tester:
  1. Turn the ignition switch to the ON position.
  2. Connect the positive tester probe of the voltmeter to terminal VG of the ECM and the negative tester probe of the voltmeter to terminal E2G of the ECM.
  3. Blow air into the air flow meter, and check if the voltage fluctuates.
    If operation is not as specified, check the MAF meter, the wiring and the ECM.