Flux test

FLUX TEST

Proceed as described for the first steps of the procedure "Throttle body - Removing/Refitting".

1. Make sure that the throttle is in the closed position, then using tool no. 1.824.011.000 (C.2.0056) connected to the flux meter, check that leakage is within the specified limits.

This current is measured by an appropriate Wheatstone bridge.
Therefore the current is proportionate with the flow of air.

NOTE: This air flow meter measures directly the mass of air (and not the volume) thereby eliminating problems of temperature, altitude, pressure, etc. Correct operation of the flow meter depends on the condition of the air cleaner, which must therefore be checked often.

1. Connector
   2. Measurement channel
   3. Hot film sensor

AIR FLOW METER

The air flow meter is of the "heated film" type.
Its operating principle is based on a heated diaphragm in a measurement channel through which the intake air admitted to the engine flows.

The hot film diaphragm is kept at a constant temperature (~ 120°C above the temperature of the incoming air) by the heating resistance placed in contact with it.
The air crossing the measurement channel tends to withdraw heat from the diaphragm, therefore in order to keep it at a constant temperature, a certain amount of current must flow to the resistance.

REMOVING/REFITTING

• Disconnect the battery (-) terminal.
• Remove the left hand engine compartment trim.

1. Slacken the two clamps fastening the upper re-sounder to the corrugated sleeve.