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Home >> Nissan-Datsun >> 2003 >> Sentra Limited >> Repair and Diagnosis >> External Pages >> Different car >> Section 112 (Engine Controls Self-Diagnostics - Pathfinder) >> Diagnostic Tests >> DTC P1102: Mass Airflow Sensor - Range/Performance >> Diagnostic Procedure

Diagnostic Procedure

WARNING: This page is about a different car, the 2003 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.
  1. Check air intake duct and vacuum hoses for disconnection. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST . If no problem is found, go to next step.
  2. Turn ignition off. Loosen and retighten 2 engine ground bolts. See Figure. Go to next step.
  3. Disconnect MAF sensor 4-pin harness connector. See Figure. Turn ignition on. Measure voltage between ground and MAF sensor harness connector terminals No. 4 (Pink/Black wire) and No. 2 (Black/White wire). See Figure. About 5 volts should exist at terminal No. 4, and battery voltage should exist at terminal No. 2. If voltage is not as specified, go to next step. If voltage is as specified, go to step  5.
  4. Check the following:
    • Check for open or short in circuits between MAF sensor and ECM relay. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
    • Check for open or short in circuits between MAF sensor and ECM.
    If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST .
  5. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location, see Figure. Check continuity of Black/Pink wire between MAF sensor harness connector terminal No. 3 and ECM harness connector terminal No. 67. See Figure. Continuity should exist. Also, check circuit for short to voltage. If no problem is found, leave harness connector disconnected and go to next step. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST .
  6. Check continuity of Orange wire between MAF sensor harness connector terminal No. 5 and ECM harness connector terminal No. 51. Continuity should exist. Also, check circuit for short to ground and short to voltage. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST .
    7. CAUTION: DO NOT use ECM ground terminals when measuring voltage.
  7. Reconnect all harness connectors. Start engine and warm to normal operating temperature. Backprobing at ECM, measure voltage between ground and ECM terminal No. 51 (Orange wire), with engine at specified speeds. See MASS AIRFLOW SENSOR VOLTAGE  table. If voltage is as specified, go to next step. If voltage is not as specified, disconnect and reconnect MAF sensor harness connector and repeat test. If voltage is still not as specified, replace MAF sensor. After repair, repeat DTC CONFIRMATION TEST .
    MASS AIRFLOW SENSOR VOLTAGE

    Condition Volts
    Key On, Engine Off About 1.0
    Engine Idling 1.2-1.8
    2500 RPM 1.6-2.2
    Idle To 4000 RPM (1) 1.2-1.8 To About 4.0
    (1) Voltage should increase in proportion to engine speed.
  8. No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
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