The Vane Air Flow (VAF) meter measures the air flowing into the engine. The meter contains a movable vane which is connected to a potentiometer. As air flows through the meter, the movable vane and potentiometer change position and provide an input to the PCM. The PCM can then translate the vane position into the volume of air flowing into the engine.
See Figure 1
- Make sure the ignition key is OFF .
- Connect jumper wires from the sensor connector to the wiring harness. This permits the engine to operate normally while you check the sensor.
- Connect a Digital Volt Ohmmeter (DVOM) set to read voltage, between sensor terminals VAF and SIG RTN.
- Turn the key ON and access the VAF meter measuring vane.
- With the vane fully closed, the voltage reading should be 4.5-5 volts.
- Slowly move the vane to the fully open position. As the vane moves through its travel the voltage should drop slowly and smoothly. When the vane reaches the end of its travel the voltage reading should be 0.5-1.5 volts.
- If the voltage readings are not within specifications, replace the VAF meter.
REMOVAL & INSTALLATION
- Disconnect the negative battery cable.
- Unfasten the engine VAF meter outlet hose-to-the vane air flow meter hose clamp, then position the outlet hose out of the way.
- Remove the air intake hose from the air cleaner.
- Unfasten the two spring clamps and position the air cleaner cover and the filter element aside.
- Unfasten the four screw and washer assemblies from the flange of the air cleaner tray where it is attached to the VAF meter assembly. Pull the air cleaner tray away from the VAF. If the tray-to-VAF meter gasket is deteriorated, replace the gasket.
- Unplug the VAF meter electrical connection.
The VAF meter-to-mounting bracket screws are different sizes. Make a note of the locations of the screws; doing so will aid during installation.
- Hold the VAF meter with one hand, and unfasten the three screws and washers which attach the meter to the bracket, then remove the meter assembly.
- Clean the mounting surfaces of the air cleaner outlet flange and the VAF meter housing.
- Place the retaining screws in the holes in the air cleaner outlet flange and, if necessary install a new gasket over the screws.
- Attach the air cleaner to the VAF meter using the screws. Tighten the screws to 33-49 inch lbs.(4-5 Nm). Make sure the gasket is seated and aligned properly.
- Attach the VAF meter to its mounting bracket using the screws, then tighten the screws to 6-9 ft. lbs. (8-12 Nm).
- Attach the VAF meter outlet tube to the VAF meter assembly and tighten the hose clamp.
- Install the air cleaner element and cover.
- Attach the air intake duct to the air cleaner.