Diagnostic Procedure For Optical 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: Optical sensor circuit is open or shorted. [50 (Driver), 52 (Passenger) or DTC 257F or B2580 is indicated on front air control as a result of conducting self-diagnosis.]

Fig 1: Diagnostic Procedure For Optical Sensor

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

CHECK CIRCUIT CONTINUITY BETWEEN OPTICAL SENSOR AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector and optical sensor connector.
3. Check continuity between optical sensor harness connector M402 terminal 1 (W/V) and 2 (G/O) and front air control harness connector M50 terminal 31 (W/V) and 40 (G/O).
  - 1 - 31: Continuity should exist.
  - 2 - 40: Continuity should exist.
4. Check continuity between optical sensor harness connector M402 terminal 1 (W/V) and 2 (G/O) and ground.
  - 1, 2 - Ground: Continuity should not exist.
OK or NG
- OK: GO TO 2.
- NG: Repair harness or connector.
Fig 2: Checking Continuity Between Optical Sensor Harness Connector M402 Terminal 1, 2 And Front Air Control Harness Connector M50 Terminal 31 And 40
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK CIRCUIT CONTINUITY BETWEEN OPTICAL SENSOR AND BCM
1. Turn ignition switch OFF.
2. Disconnect BCM connector and optical sensor connector.
3. Check continuity between optical sensor harness connector M402 terminal 3 (P) and BCM harness connector M18 terminal 18 (P).
  - 3 - 18: Continuity should exist.
4. Check continuity between optical sensor harness connector M402 terminal 3 (P) and ground.
  - 3 - Ground: Continuity should not exist.
OK or NG
- OK: Replace optical sensor. Refer to "OPTICAL SENSOR ".
- NG: Repair harness or connector.
Fig 3: Checking Continuity Between Optical Sensor Harness Connector M402 Terminal 3 And BCM Harness Connector M18 Terminal 18
Courtesy of NISSAN MOTOR CO., U.S.A.