Rear Window Defogger Switch Circuit Check

WARNING: This page is about a different car, the 2005 Infiniti G35. However, it is still accessible from the selected car via links, so may be relevant.

CHECK REAR WINDOW DEFOGGER SWITCH OPERATION
With CONSULT-II

Check ("REAR DEF SW", "IGN ON SW") in DATA MONITOR mode with CONSULT-II.

When rear defogger switch is turned to ON

REAR DEF SW: ON

When ignition switch is turned to ON

IGN ON SW: ON

Fig 1: REAR DEF SW, IGN ON SW Data Monitor
Courtesy of NISSAN MOTOR CO., U.S.A.

With out CONSULT-II
1. Turn ignition switch ON.
2. Check voltage between BCM connector ground.
  
  Fig 2: Voltage Check Between BCM Connector Ground Table
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 3: Checking Voltage Between BCM Connector Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: Rear window defogger switch check is OK.
2. NG: GO TO 2.
CHECK REAR WINDOW DEFOGGER SWITCH CIRCUIT HARNESS CONTINUITY
1. Turn ignition switch OFF.
2. Disconnect BCM and A/C and audio controller connector.
3. Check continuity between BCM connector M1 terminal 9 and A/C and audio controller connector M38 terminal 12.
  9 (L/R) - 12(L/R): Continuity should exist
4. Check continuity between A/C and audio controller connector M38 terminal 12 and ground
  12 (L/R) - Ground: Continuity should not exist
  
  OK or NG
  1. OK: GO TO 3.
  2. NG: Repair or replace harness.
    
    Fig 4: Checking Continuity Between A/C And Audio Controller Connector M38 Terminal 12 And Ground
    Courtesy of NISSAN MOTOR CO., U.S.A.
5. CHECK BCM OUTPUT SIGNAL
  1. Connect BCM connector.
  2. Check continuity between BCM connector M3 terminal 9 and ground.
    9 (L/R) - Ground: Battery voltage
  OK or NG
  1. OK: Replace A/C and audio controller.
  2. NG: Replace BCM.
    
    Fig 5: Checking Continuity Between BCM Connector M3 Terminal 9 And Ground
    Courtesy of NISSAN MOTOR CO., U.S.A.