Air Flow Meter/Sensor: Testing and Inspection

Circuit Diagram

Troubleshooting Hints

1. If the engine stalls occasionally, crank the engine and shake the volume air flow sensor harness. If the engine stalls, check for the poor contact of the volume air flow sensor connector.
2. If the volume air flow sensor output frequency is other than 0 when the ignition switch is turned on (do not start the engine), Check for the faulty volume air flow sensor or engine control module.
3. If the engine can be idle even if the volume air flow sensor output frequency is out of specification, check for the following conditions:
- Disturbed air flow in the volume air flow sensor. Disconnected air duct, clogged air cleaner filter.
- Poor combustion in the cylinder: faulty ignition plug, ignition coil, injector, incorrect compression.
- Air leaks in the intake manifold.
- Loose EGR valve seat.





Using Scan Tool

NOTE: When the vehicle is new (within Initial operation of about 300 miles), the volume air flow sensor output frequency may be about 10% higher.











Harness inspection Procedures