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Home >> Nissan-Datsun >> 2003 >> Frontier Base, Automatic >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0112: Intake Air Temperature Sensor Circuit Low Input Or DTC P0113: Intake Air Temperature Sensor Circuit High Input >> Diagnostic Procedure
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Diagnostic Procedure

  1. Turn ignition off. Disconnect MAF sensor harness connector. See Fig 1 or Fig 2 . Turn ignition on. Measure voltage between ground and IAT sensor harness connector terminal No. 1 (Purple/Red wire). If voltage is about 5 volts, go to step  3 . If voltage is not about 5 volts, go to next step.
  2. Check the following:
    • Check for poor connection at Super Multiple Junction (SMJ) connector M65, terminal 15A (Purple/Red wire). See Fig 3 . SMJ connector M65 is located under right side of instrument panel. See Figure .
    • On 2.4L models, check for poor connection at White, 20-pin connector M81, terminal No. 19 (Purple/Red wire). See Figure . Connector M81 is located behind right side of instrument panel.
    • On 3.3L models, check for poor connection at White, 24-pin connector M81, terminal No. 22 (Purple/Red wire). See Fig 4 . Connector M81 is located behind right side of instrument panel.
    • On all models, check for open or short between IAT sensor and ECM.

    Repair as necessary.

  3. Check continuity between engine ground and IAT sensor harness connector terminal No. 2 (Black/White wire on 2.4L models; Brown wire on 3.3L models). Continuity should exist. Also, check circuit for short to voltage. If problem is found, go to next step. If problem is not found, go to step  5 .
  4. Check the following:
    • Check for poor connection at Super Multiple Junction (SMJ) connector M65, terminal 20B (Black/White wire on 2.4L models; Brown wire on 3.3L models). See Fig 3 . SMJ connector M65 is located under right side of instrument panel. See Figure .
    • On 2.4L models, check for poor connection at White, 20-pin connector M81, terminal No. 1 (Black/White wire). See Figure . Connector M81 is located behind right side of instrument panel.
    • On 3.3L models, check for poor connection at White, 24-pin connector M81, terminal No. 2 (Brown wire). See Fig 4 . Connector M81 is located behind right side of instrument panel.
    • On all models, check for open or short between IAT sensor and ECM.

    Repair as necessary.

  5. Remove IAT sensor, and place in heated water. Measure resistance between IAT sensor terminals. Resistance should be within acceptable range shown in illustration. See Fig 5 . If resistance is as specified, go to next step. If resistance is not as specified, replace IAT sensor.
  6. No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
Fig 1: Locating IAT Sensor (2.4L)
G00147158Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 2: Locating IAT Sensor (3.3L)
G00147159Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 3: Identifying SMJ Connectors M65 & E43 Terminals
G00147160Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 4: Identifying Connector M81 Terminals (3.3L)
G00147161Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 5: Checking Temperature Sensor Resistance
G99I08868Courtesy of NISSAN MOTOR CO., U.S.A.
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