Air Flow Meter/Sensor: Testing and Inspection

INSPECTION








Using Scan tool

Check Item: Volume Air Flow Sensor
Data Display: Sensor air volume
Check Conditions:
- Engine coolant temperature: 80 - 95°C (176 - 205°F)
- All accessories OFF
- Transaxle in neutral (P range for auto trans)
- Steering wheel centered

With engine at 750 rpm: 27 - 33 Hz
With engine at 2,000 rpm: 60 - 80 Hz
With engine racing: frequency increases with racing

NOTE: When the vehicle is new (within initial operation of about 500 km [300 miles]), the Volume Air Flow Sensor output frequency may be about 10% higher.

Harness Inspection Procedure





1. Measure the power supply voltage.
- Connector disconnected
- Ignition Switch ON
- Voltage should be at system voltage

If OK - go to step 2
If not OK - repair the harness (H2 Control Relay) or check the Control Relay.





2. Measure the terminal voltage.
- Connector disconnected
- Ignition Switch ON
- Voltage should be 4.8 - 5.2 volts

If OK - go to step 3
If not OK - repair the harness (H3 - C50-5 14)





3. Check for continuity of ground circuit.
- Connector disconnected

If OK - END
If not OK - repair the harness (H6 - C50-5 12)

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 Exhaust Gas Recirculation Valve seat.