Checking and removing
1. We prepare the car for work (see «Preparing the car for maintenance and repair»).
2. Press the pad retainer and disconnect the wiring harness block from the mass air flow sensor.
3. Connect «negative» voltmeter probe to «mass» (to the engine).
4. Turning on the ignition, use a voltmeter to measure the supply voltage at terminal 2 of the wiring harness block (pin numbering is done on the sensor).
Comment. The voltage at the output must be at least 12 V. If the voltage is not supplied to the block or it is less than 12 V, then the battery is discharged, the power circuit is faulty or the computer is faulty.
5. Using a voltmeter, we measure the supply voltage at terminal 4 of the wiring harness block.
Comment. The voltage at the output should be about 5 V. If the voltage is not correct, then the sensor power supply circuit is faulty or the computer is faulty.
6. Using a Phillips screwdriver, loosen the clamp and disconnect the air supply hose from the sensor.
7. Using a 10 mm socket wrench, unscrew the two bolts securing the mass air flow sensor.
8. Remove the sensor and remove the sealing ring.
Advice. You can verify that the mass air flow sensor is faulty by replacing it with a known good one.
Installation
Install the sensor in the reverse order of removal.