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DTC P0100 (QA): Mass Airflow (MAF) Sensor Circuit Malfunction

  1. Turn ignition off. Connect SSM. Turn ignition and scan tool on. Start engine. Select SSM function mode F06 to read voltage input from MAF sensor. If sensor output voltage is 0.3-5.0 volts and/or mass airflow value is 1.3-250 g/sec, check for a poor connection, short or open in sensor circuit or ground wires. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair as necessary. If value reading is less than 0.3 volt (1.3 g/sec), go to next step. If wiring is good and reading is more than 0.3 volt (1.3 g/sec), go to step 5).
  2. Start and idle engine. Using DVOM connected to chassis ground, backprobe ECM connector terminal No. 5. If voltage reading is 0.3 volt or less, go to next step. If voltage reading is more than 0.3 volt while shaking wiring and connector, repair terminal contact in ECM connector. If voltage reading remains less than 0.3 volt, replace ECM.
  3. Turn ignition off. Disconnect MAF sensor wiring. Turn ignition on. Check voltage between MAF sensor connector terminal No. 1 and chassis ground. If voltage reading is 10 volts or more, go to next step. If voltage is less than 10 volts, repair open in wiring between main relay connector and MAF sensor connector.
  4. Turn ignition off. Disconnect ECM connector. Check resistance between ECM connector terminal No. 5 and MAF sensor connector terminal No. 4, between ECM connector terminal No. 7 and MAF sensor connector terminal No. 3, and between ECM connector terminal No. 20 and MAF sensor connector No. 2. If resistance is one ohm or less in each instance, replace MAF sensor. If resistance is more than one ohm on any circuit, repair affected circuit between ECM and MAF sensor connector.
  5. Turn ignition off. Disconnect MAF sensor connector. Turn SSM and ignition on. Select SSM function mode F06. If reading is more than 5 volts (250 g/sec), repair short to voltage in circuit between ECM and MAF sensor connector. If reading is less than 5 volts (250 g/sec), check for poor contact in MAF sensor connector. Repair as necessary. If contact is okay, replace MAF sensor.
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