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Home >> Isuzu >> 2007 >> Ascender RWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System & Fuel System - 4.2L - DTC P0013 To DTC P0134 >> DTC P0102 or P0103 >> Circuit/System Description

Circuit/System Description

The mass air flow (MAF) sensor is integrated with the intake air temperature (IAT) sensor. The MAF sensor is an air flow meter that measures the amount of air entering the engine. The powertrain control module (PCM) uses the MAF sensor signal to provide the correct fuel delivery for all engine speeds and loads. A small quantity of air entering the engine indicates a deceleration or idle condition. A large quantity of air entering the engine indicates an acceleration or high load condition. The MAF/IAT sensor has the following circuits:

The PCM applies 5 volts to the MAF sensor on the MAF sensor signal circuit. The sensor uses the voltage to produce a frequency signal based on the inlet air flow through the sensor bore. The frequency signal varies in a range of near 1,500 Hertz at idle to near 9,500 Hertz at maximum engine load. The PCM converts the Hertz input signal to a grams per second (g/s) value. This value is displayed on the scan tool as the MAF Sensor g/s parameter.

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