Diagnostic Procedure For Intake Sensor

WARNING: This page is about a different car, the 2005 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. (56, 57 or DTC B2581, B2582 is indicated on front air control as a result of conducting Self-diagnosis).

Fig 1: Diagnostic Procedure For Intake Sensor

Courtesy of NISSAN MOTOR CO., U.S.A.

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 (L/B) and ground.
  - 2 - Ground: Approx. 5V
OK or NG
- OK: GO TO 2.
- NG: GO TO 4.
Fig 2: Checking Voltage Between Intake Sensor Harness Connector M146 Terminal 2 (L/B) And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.
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 (V/R) and front air control harness connector M49 terminal 21 (V/R).
  - 1 - 21: Continuity should exist.
OK or NG
- OK: GO TO 3.
- NG: Repair harness or connector.
Fig 3: Checking Continuity Between Intake Sensor Harness Connector M146 Terminal 1 And Front Air Control Harness Connector M49 Terminal 21
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK INTAKE SENSOR
Refer to "INTAKE SENSOR ".

OK or NG
- OK:
  1. Replace front air control. Refer to "FRONT AIR CONTROL ".
  2. Go to self-diagnosis "A/C SYSTEM SELF-DIAGNOSIS FUNCTION " and perform self-diagnosis.
- NG:
  1. Replace intake sensor. Refer to "INTAKE SENSOR ".
  2. Go to self-diagnosis "A/C SYSTEM SELF-DIAGNOSIS FUNCTION " and perform self-diagnosis.
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 (L/B) and front air control harness connector M49 terminal 9 (L/B).
  - 2 - 9: Continuity should exist.
4. Check continuity between intake sensor harness connector M146 terminal 2 (L/B) and ground.
  - 2 - Ground: Continuity should not exist.
OK or NG
- OK:
  1. Replace front air control. Refer to "FRONT AIR CONTROL ".
  2. Go to self-diagnosis "A/C SYSTEM SELF-DIAGNOSIS FUNCTION " and perform self-diagnosis.
- NG: Repair harness or connector.
Fig 4: Checking Continuity Between Intake Sensor Harness Connector M146 Terminal 2 And Front Air Control Harness Connector M49 Terminal 9
Courtesy of NISSAN MOTOR CO., U.S.A.