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Diagnostic Procedure For Intake Sensor

WARNING: This page is about a different car, the 2006 Infiniti QX56. However, it is still accessible from the selected car via links, so may be relevant.

SYMPTOM: Intake sensor circuit is open or shorted. Using the CONSULT- II, DTC B2581 or B2582 is displayed. Without a CONSULT-II, code 56 or 57 is indicated on front air control as a result of conducting the front air control self-diagnosis.

Fig 1: Intake Sensor Circuit
G04135961Courtesy of NISSAN MOTOR CO., U.S.A.
  1. CHECK VOLTAGE BETWEEN INTAKE SENSOR AND GROUND 
    1. Disconnect intake sensor connector.
    2. Turn ignition switch ON.
    3. Check voltage between intake sensor harness connector M146 terminal 2 and ground.

      2 - Ground : Approx. 5V 

    OK or NG 

    1. OK : GO TO 2.
    2. NG : GO TO  4.
      Fig 2: Identifying Voltage Between Intake Sensor Connector M146 Terminal 2 And Ground
      G04135962Courtesy of NISSAN MOTOR CO., U.S.A.
  2. CHECK CIRCUIT CONTINUITY BETWEEN INTAKE SENSOR AND FRONT AIR CONTROL 
    1. Turn ignition switch OFF.
    2. Disconnect front air control connector.
    3. Check continuity between intake sensor harness connector M146 terminal 1 and front air control harness connector M49 terminal 21.

      1 - 21 : Continuity should exist. 

    OK or NG 

    1. OK : GO TO 3.
    2. NG : Repair harness or connector.
      Fig 3: Identifying Connector M146 Terminal 1 And Front Air Control Connector M49 Terminal 21
      G04135963Courtesy of NISSAN MOTOR CO., U.S.A.
  3. CHECK INTAKE SENSOR 

    Refer to "INTAKE SENSOR ".

    OK or NG 

    1. OK :
      1. Replace front air control. Refer to "FRONT AIR CONTROL "
      2. Go to "A/C SYSTEM SELF-DIAGNOSIS FUNCTION " and perform self-diagnosis.
    2. NG :
      1. Replace intake sensor. Refer to "INTAKE SENSOR ".
      2. Go to "A/C SYSTEM SELF-DIAGNOSIS FUNCTION " and perform self-diagnosis.
  4. CHECK CIRCUIT CONTINUITY BETWEEN INTAKE SENSOR AND FRONT AIR CONTROL 
    1. Turn ignition switch OFF.
    2. Disconnect front air control connector.
    3. Check continuity between intake sensor harness connector M146 terminal 2 and front air control harness connector M49 terminal 9.

      2 - 9 : Continuity should exist. 

    4. Check continuity between intake sensor harness connector M146 terminal 2 and ground.

      2 - Ground : Continuity should not exist. 

      Fig 4: Identifying Continuity Between Intake Sensor Connector M146 Terminal 2 And Ground
      G04135964Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK :
      1. Replace front air control. Refer to "FRONT AIR CONTROL ".
      2. Go to "A/C SYSTEM SELF-DIAGNOSIS FUNCTION " and perform self-diagnosis.
    2. NG : Repair harness or connector.