K Yukon/Denali 4WD V8-6.5L DSL Turbo VIN S (1999)
Mass Air Flow (MAF) Sensor: Description and Operation
Mass Air Flow (MAF) Sensor
The Mass Air Flow (MAF) sensor measures the amount of air which passes through it. The PCM uses this information to determine the operating
condition of the engine, to control EGR operation. A large quantity of air indicates acceleration. A small quantity of air indicates deceleration or idle.
The scan tool reads the MAF value and displays it in Grams per Cylinder, Grams per Second (gm/s), and Hertz (Hz). Values should change rather
quickly on acceleration, but values should remain fairly stable at any given RPM. When the PCM detects a malfunction in the MAF sensor circuit, the
following DTCs will set:
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DTC P0101 system performance.
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DTC P0102 frequency low.
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DTC P0103 frequency high.