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Home >> Infiniti >> 1995 >> Q45 Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes 4.5L >> Diagnostic Trouble Code (DTC) Testing >> DTC 12: Mass Airflow (MAF) Sensor
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DTC 12: Mass Airflow (MAF) Sensor

  1. Check Power Supply

    Turn ignition off and disconnect MAF sensor harness connector. Turn ignition on. Measure voltage between MAF sensor harness connector terminal "a" (Black/White wire) and ground. See Fig 1 and Fig 2 . If battery voltage is present, go to next step. If battery voltage is not present, verify harness continuity between MAF sensor and ECM, and MAF sensor and ECCS relay. Repair harness or connectors as necessary.
  2. Check Ground Circuit

    Turn ignition off and disconnect ECM harness connector. Verify harness continuity between MAF sensor connector terminal "b" (Black wire) and ECM connector terminal No. 26. See Figure , Figure and Fig 2 . If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary.
  3. Check Input Signal Circuit

    Turn ignition off and disconnect ECM harness connector. Check continuity between MAF sensor connector terminal "c" (White wire) and ECM terminal No. 27. See Figure , 2and 9. If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary.
  4. Check Component

    Inspect MAF sensor. See I - SYSTEM/COMPONENT TESTS article. Replace MAF sensor if necessary and perform FINAL CHECK  .
Fig 1: Locating MAF Sensor Harness Connector (Q45)
G93J78575Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 2: DTC 12, Checking Power Supply (Q45)
G93A78576Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 3: DTC 12, Checking Ground Circuit (Q45)
G93B78577Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 4: DTC 12, Checking Input Signal Circuit (Q45)
G93C78578Courtesy of NISSAN MOTOR CO., U.S.A.