General description
53. The mass air flow (MAF) sensor is located in the throttle body near the intake manifold. This sensor is used to measure the amount of air entering the engine. The PCM uses this information to control fuel delivery. The intake of a large volume of air means the need to accelerate the car, and a small volume means the need to reduce engine speed or switch it to idle mode.
Examination
54. To check the MAF sensor, start the engine, let it idle for at least 1 minute and check if fault code 34 (see section 3).
55. With the ignition off, connect the tester to the electrical contacts of the sensor connector. Set the ignition key to the "ON" position (but don't start the engine). Using a voltmeter, measure the voltage at pin "A" in the speed sensor connector (see illustration). The voltmeter readings should be between 4-6 volts. If the voltage is outside these limits, check the yellow wire going to contact "A" for a break.
4.55 Measure the voltage at contact "A" (yellow wire), by connecting the positive terminal of the voltmeter to it. The device should show a voltage of 4-6 V
56. If the voltage at terminal "A" complies with the requirements, connect the test lamp leads to terminals "B" and "C" (with the ignition key still in the "ON" position). The lamp should light.
57. If the test lamp does not light, check the pink and black wire going to contact "C" for a break. If the lamp does not light, take the MAF sensor to a service station for inspection.
58. If the sensor is found to be faulty, replace it.
Replacement
59. To replace the sensor, first disconnect its connector.
60. Unscrew the two bolts securing the sensor to the throttle body and remove the sensor from the engine compartment.
4.60. Unscrew the bolts (shown by arrows) air flow sensor and disconnect the sensor from the throttle body
61. The speed sensor is installed in the reverse order.