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Home >> Nissan-Datsun >> 2003 >> Sentra Limited >> Repair and Diagnosis >> External Pages >> Different car >> Section 40 (Engine Controls - Self-Diagnostics - 2.5) >> Diagnostic Tests >> DTC P0101, DTC P0102, DTC P0103 & P1102 >> Diagnostic Procedure

Diagnostic Procedure

WARNING: This page is about a different car, the 2002 Nissan Sentra. 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", "D" or "E" 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 and Fig 2 . Disconnect MAF sensor harness connector located near air cleaner. Turn ignition on. Measure voltage between ground and MAF sensor harness connector terminals No. 2 (Red wire) and No. 4 (White wire). See Fig 3. About 5 volts should exist at terminal No. 2, and battery voltage should exist at terminal No. 4. If voltage is as specified, go to next step. If voltage is not as specified, repair open or short circuit and retest system. See 2.5L under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS in ELECTRICAL.
  3. Turn ignition off. Disconnect ECM harness connector. See Figure. Check continuity of Black wire between MAF sensor harness connector terminal No. 3 and ECM harness connector terminal No. 73. 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 Green wire between MAF sensor harness connector terminal No. 1 and ECM harness connector terminal No. 61. 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 ECM terminal No. 61 (Green wire) by backprobing, with engine at specified speeds. See MASS AIRFLOW SENSOR VOLTAGE SPECIFICATIONS . 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. No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLESHOOTING - NO CODES article.
MASS AIRFLOW SENSOR VOLTAGE SPECIFICATIONS

Condition Volts
Key On, Engine Off Approximately 1.0
Engine Idling 1.1-1.5
2500 RPM 1.6-2.0
Idle To 4000 RPM (1) 1.5-2.0 To About 4.0
(1) Voltage should increase in proportion to engine speed.
Fig 1: Locating Engine Ground (Engine Compartment)
G00199754Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 2: Locating Engine Ground (Passenger Compartment)
G00199758Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 3: Identifying MAF Sensor Harness Connector Terminals
G00014342Courtesy of NISSAN MOTOR CO., U.S.A.
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