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Home >> Nissan-Datsun >> 2003 >> Sentra Limited >> Repair and Diagnosis >> External Pages >> Different car >> Section 41 (Engine Controls - Self-Diagnostics - Quest) >> Diagnostic Tests >> DTC P0100: Mass Airflow Sensor >> Diagnostic Procedure

Diagnostic Procedure

WARNING: This page is about a different car, the 2002 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.
  1. If malfunction "A" or "C" was duplicated, go to next step. If malfunction "B" or "D" was duplicated, inspect air intake duct and vacuum hoses for disconnection or leaks. Reconnect or repair as necessary and retest system. If no problems are found, go to next step.
  2. Turn ignition off. Loosen and retighten engine ground bolts. See Fig 1. Disconnect MAF sensor harness connector located near air cleaner. Turn ignition on. Measure voltage between ground and MAF sensor harness connector terminal No. 3 (Black/White wire). If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit and retest system. See WIRING DIAGRAMS article.
  3. Turn ignition off. Disconnect ECM harness connector. See Figure. Check continuity of Blue/Orange wire between MAF sensor harness connector terminal No. 2 and ECM harness connector terminal No. 55. See Figure. Continuity should exist. Also, check circuit for short to ground and short to voltage. Repair circuit as necessary and retest system. If circuit is okay, go to next step.
  4. Check continuity of White/Blue wire between MAF sensor harness connector terminal No. 1 and ECM harness connector terminal No. 54. Also, check circuit for short to ground and short to voltage. Repair circuit as necessary and retest system. If circuit is okay, go to next step.
    5. CAUTION: DO NOT use ECM ground terminals when measuring voltage.
  5. Reconnect all harness connectors. Start engine and warm to normal operating temperature. Measure voltage between ground and MAF sensor signal circuit at ECM terminal No. 54 (White/Blue wire) by backprobing, 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 and retest system.
  6. Turn ignition off. Disconnect connector F-103. See Fig 2. Check continuity between ground and connector F-103 terminal No. 3 (Black/Red wire). See Fig 3. Continuity should exist. Also, check circuit for short to voltage. Repair circuit as necessary and retest system. If circuit is okay, go to next step.
  7. No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
MASS AIRFLOW SENSOR VOLTAGE

Condition Volts
Key On, Engine Off Less Than 1.0
Engine Idling 1.0-1.7
2500 RPM 1.7-2.3
Idle To 4000 RPM (1) 1.0-1.7 To About 4.0
(1) Voltage should increase in proportion to engine speed.
Fig 1: Locating Engine Ground Bolts
G99E51999Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 2: Identifying Engine Control Harness Connector Locations Behind Instrument Panel
G00042086Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 3: Identifying Connector F-103 Terminals
G00042087Courtesy of NISSAN MOTOR CO., U.S.A.
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