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Home >> Nissan-Datsun >> 2002 >> Frontier Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0101: Mass Airflow Sensor Circuit Range/Performance Problem >> Diagnostic Procedure

Diagnostic Procedure

  1. If malfunction "A" or "C" was duplicated, go to next step. If malfunction "B" or "D" was duplicated, check air intake duct and vacuum hoses for disconnection. If problem is found, repair as necessary. If problem is not found, go to next step.
  2. Turn ignition off. Loosen and retighten engine ground bolts. See Fig 1 or Fig 2 . Disconnect MAF sensor harness connector. See Fig 3 or Fig 4 . Turn ignition on. Measure voltage between ground and MAF sensor harness connector terminal No. 2 (Black/Pink wire). If battery voltage exists, go to step  4 . If battery voltage does not exist, go to next step.
  3. Check the following:
    • Check for open or short between ECM relay and MAF sensor.
    • Check for open or short between ECM and MAF sensor.

    Repair as necessary.

  4. Turn ignition off. Disconnect ECM harness connector. See Figure or Figure . Check continuity of Green wire between MAF sensor harness connector terminal No. 3 and ECM harness connector terminal No. 55. See Figure . Also, check circuit for short to ground and short to voltage. If problem is found, repair as necessary. If problem is not found, go to next step.
  5. Check continuity of Red wire between MAF sensor harness connector terminal No. 4 and ECM harness connector terminal No. 54. Also, check circuit for short to ground and short to voltage. If problem is found, repair as necessary. If problem is not found, go to next step.
    6. CAUTION: DO NOT use ECM ground terminals when measuring voltage.
  6. Reconnect all harness connectors. Start engine and warm to normal operating temperature. Measure voltage between ground and ECM terminal No. 54 by backprobing, with engine at specified speeds. See appropriate MASS AIRFLOW SENSOR VOLTAGE table. If voltage is as specified, go to step  8 . If voltage is not as specified, go to next step.
  7. Turn ignition off. Disconnect and reconnect MAF sensor harness connector. Repeat step  6 . If voltage is still not as specified, remove MAF sensor. Check hot wire for damage or dust. If problem is found, clean or replace MAF sensor as necessary. If problem is not found, go to next step.
  8. Turn ignition off. Disconnect Gray, 6-pin joint connector No. 2 (connector F32) located near ECM. See Figure , Figure or Figure . Check the following:
    • Check continuity between ground and connector F32 terminal No. 1 (Black/Yellow wire).
    • Check continuity between each joint connector terminal (component side).

    Continuity should exist. Also, check circuit for short to voltage. If problem is found, repair as necessary. If problem is not found, go to next step.

  9. No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
MASS AIRFLOW SENSOR VOLTAGE (2.4L)

Condition Volts
Key On, Engine Off Less Than 1.0
Engine Idling 0.9-1.8
2500 RPM 1.9-2.3
Idle To 4000 RPM (1) 0.9-1.8 To About 3.0
(1) Voltage should increase in proportion to engine speed.
MASS AIRFLOW SENSOR VOLTAGE (3.3L)

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 (2.4L)
G00147151Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 2: Locating Engine Ground Bolts (3.3L)
G00147152Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 3: Locating MAF Sensor (2.4L)
G00147153Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 4: Locating MAF Sensor (3.3L)
G00147154Courtesy of NISSAN MOTOR CO., U.S.A.
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