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Home >> Geo >> 1992 >> Prizm Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Diagnostic Charts >> Code 31, Mass Airflow (MAF) Sensor (PRIZM GSI) >> Notes

Code 31, Mass Airflow (MAF) Sensor (PRIZM GSI): Notes

MAF sensor measures flow of air passing into engine. ECM uses this input to monitor operating condition of engine in calculating fuel delivery. A large air movement indicates acceleration and a small movement indicates deceleration or idle. MAF sensor produces a frequency signal not easily measured. Sensor can be diagnosed using procedures in this test. MAF sensor also contains fuel pump control switch, which provides ground to circuit opening relay to run fuel pump once engine has started.

NOTE: Test numbers refer to test numbers on diagnostic chart.
  1. Verifies B+ and ground at MAF sensor.
  2. Verifies proper voltage control to ECM from MAF sensor.
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