Diagnostic Procedure For Optical Sensor

WARNING: This page is about a different car, the 2005 Nissan Quest. 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) or 52 (passenger) is indicated on front air control as a result of conducting self-diagnosis.]

Fig 1: Connecting Optical Sensor Between Front Air Control & BCM

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 (LG) and 2 (SB) and front air control harness connector M50 terminal 40 (LG) and 31 (SB).
  
  Fig 2: Checking Circuit Continuity Between Optical Sensor Harness Connector Terminals 1, 2 & Front Air Control Harness Connector Terminals 31, 40
  Courtesy of NISSAN MOTOR CO., U.S.A.
  - Continuity should exist.
4. Check continuity between optical sensor harness connector M32 terminal 1 (LG) and 2 (SB) and ground.
  Continuity should not exist.
OK or NG
- OK: GO TO 2.
- NG: Repair harness or connector.
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).
  - Continuity should exist.
4. Check continuity between optical sensor harness connector M402 terminal 3 (P) and ground.
  Continuity should not exist.
  
  Fig 3: Checking Continuity Between Optical Sensor Harness Connector Terminal 3 & Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
- OK: Replace optical sensor.
- NG: Repair harness or connector.