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Home >> Nissan-Datsun >> 2004 >> Frontier Base, Standard >> Repair and Diagnosis >> Engine Performance >> Engine Control System - KA24DE >> DTC P0121: TP Sensor >> Component Inspection >> Mass Air Flow Sensor
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Mass Air Flow Sensor

  1. Turn ignition switch ON.
  2. Start engine and warm it up to normal operating temperature.
  3. Check voltage between ECM terminal 54 (mass air flow sensor signal) and ground.
    Fig 1: Voltage Chart
    G00857045Courtesy of NISSAN MOTOR CO., U.S.A.
    Fig 2: Checking Voltage Between ECM Terminal And Ground
    G00857046Courtesy of NISSAN MOTOR CO., U.S.A.
  4. If the voltage is out of specification, disconnect mass air flow sensor harness connector and connect it again. Repeat above check.
  5. If NG, remove mass air flow sensor from air duct. Check hot wire for damage or dust.
    Fig 3: Identifying Mass Air Flow Sensor
    G00857047Courtesy of NISSAN MOTOR CO., U.S.A.