Air Flow Meter/Sensor: Testing and Inspection

Circuit Diagram





Troubleshooting Procedures

Troubleshooting Hints
1. If the engine stalls occasionally, crank the engine and shake the mass air flow sensor harness. If the engine stalls, check the poor contact of the mass air flow sensor connector.
2. If the mass air flow sensor output voltage is other than the ignition switch is turned on (do not start the engine). Check for the faulty mass air flow sensor or engine control module.
3. If the engine can be idle even if the mass air flow sensor output voltage is out of specification, check for the following conditions;
- Disturbed air flow in the mass 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





Using Scan Tool





Using Voltmeter

NOTE: When the vehicle is new (within initial operation of about 300 miles, the mass air flow sensor air quantity may be about 10% higher.














Harness Inspection Procedure