Air Flow Meter/Sensor: Testing and Inspection

Air Flow Sensor Circuit:

NOTE: Use voltmeter with high-impedance (10 kV minimum) or digital type voltmeter.


1. Connect AFS coupler.
2. Remove coupler seal from AFS coupler.
3. Connect battery negative cable.

Checking Air Flow Sensor:

4. Connect voltmeter between coupler terminals "B" and "C".
Turn ignition switch ON and check that voltage is about 12V. If not, check if wire harness is open or connection at A3 and A5 is poor.
5. After confirming voltage between "B" and "C" as in step 4, check voltage (signal voltage) between "D" and "C".

NOTE: Using air pressure from compressed air will destroy air flow meter, always used low air pressure for testing purposes.

6. Voltmeter reading should be as specified below when air is not blown to hot wire, while it should increase as air is blown harder.

Signal voltage when air is not blown 0.2 - 0.8 volt

If check result doesn't satisfy above description, AFS coupler connection is poor or AFS is faulty.


7. Install coupler seal securely.