Air Flow Meter/Sensor: Testing and Inspection

Fig. 4 Checking Air Flow Meter Terminal Voltage:

1. Remove rubber boot from connector, Fig. 4, and turn ignition switch to ``On.''

Fig. 27 Air flow meter connector terminal identification.:

2. Using voltmeter, check voltage between each terminal and ground, Fig. 27.
3. If voltage is not .7-2.7 volts at Vs terminal, 6-10 volts at VC terminal and approximately 12 volts at VB and FC terminals, check main fuse, main relay, resistance in air flow meter and the wiring harnesses.
4. Install rubber boot to connector.
5. Remove connector from air flow meter.

Fig. 25 Air flow meter terminal identification.:

6. Using ohmmeter, measure resistance between terminals as follows:
a. Resistance between terminals E2 and VS, Fig. 25, should be greater than 20 ohms.
b. Resistance between terminals E2 and VC should be 100-300 ohms.
c. Resistance between terminals E2 and VB should be 200-400 ohms.
d. Resistance between E2 and THA should be 13.6-18.4k ohms at 4°F, 2.205-2.695k ohms at 68°F and .493-.667k ohms at 140°F.
e. Resistance between terminals E1 and FC should be infinite.
7. Press open measuring plate.
8. Using an ohmmeter, check resistance between terminals of connector. Resistance between terminals E2 and VS should be less than 400 ohms. There should be no resistance between terminals E1 and FC.
9. If resistance is not within specifications, replace air flow meter assembly.