Examination
1. Prepare the car for work (see "Preparing the car for maintenance and repair").
2. Press the connector lock and disconnect the wiring harness connector from the mass air flow sensor.
3. Connect the "negative" probe of the voltmeter to the "mass" (to the engine).
4. Turn on the ignition and use a voltmeter to measure the supply voltage at terminal 2 of the wiring harness connector (the terminal numbers are marked on the sensor).
Note: The voltage at the terminal must be at least 12 V. If the voltage does not reach the connector or is less than 12 V, the battery is discharged, the power supply circuit is faulty, or the ECU is faulty.
5. Using a voltmeter, measure the supply voltage at terminal 4 of the wiring harness connector.
Note: The voltage at the terminal should be about 5 V. If the voltage is not normal, the sensor power supply circuit is faulty or the ECU is faulty.
Removal
1. Loosen the clamp and disconnect the air supply hose from the mass air flow sensor. Using a socket wrench by 10 mm we unscrew the two bolts securing the mass air flow sensor.
2. Remove the sensor.
Tip: You can verify that the mass air flow sensor is faulty by replacing it with a known good one.
Installation
We install the sensor in the reverse order of removal.