Rear Window Defogger Control System Inspection.

• Check that any of the following fuses in the rear window defogger is blown.

Fig 1: Rear Window Defogger Fuse Condition Inspection Chart

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

OK or NG? 

1. OK >> GO TO 2.
2. NG >> If fuse is blown, be sure to eliminate cause of problem before installing new fuse, refer to SYSTEM WIRING DIAGRAMS article .

• Disconnect the rear window defogger and door mirror defogger relay B8.
• Check voltage between rear window defogger and door mirror defogger relay harness connector B8 terminals 1(W/G),3(R/B), 6(L) and body ground.

Fig 2: Rear Window And Door Mirror Defogger Relay Connector Terminal Voltage Specifications

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

Fig 3: Checking Rear Window And Door Mirror Defogger Relay Power Supply Circuit

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OK or NG? 

1. OK >> GO TO 3.
2. NG >> Check harness for open and short between rear window defogger and door mirror defogger relay and fuse.

Connect the rear window defogger and door mirror defogger relay.

With CONSULT-II

• Using "REAR DEFOGGER RLY" in the ACTIVE TEST, check the operation. refer to "ACTIVE TEST  ".
  Fig 4: Checking Rear Window Defogger And Door Mirror Defogger Relay (1 Of 2)

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  Without CONSULT-II

• GO TO 4.

OK or NG? 

1. OK >> GO TO  5 .
2. NG >> Replace the rear window defogger and door mirror defogger relay.

• Disconnect the rear window defogger and door mirror defogger relay B8.
• Check continuity between terminals 3(R/B) and 5(L/R),6(L) and 7(L/R).
  Fig 5: Terminals Continuity Specifications

  Courtesy of NISSAN MOTOR CO., U.S.A.
  Fig 6: Checking Rear Window Defogger And Door Mirror Defogger Relay (2 Of 2)

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

OK or NG? 

1. OK >> GO TO 5.
2. NG >> Replace the rear defogger and door mirror defogger relay.

With CONSULT-II

• Check the operation on "DEFOGGER SW" in the DATA MONITOR. Refer to "DATA MONITOR  ".
  Fig 7: Rear Window Defogger (Multifunction) Switch Inspection With CONSULT-II

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  Without CONSULT-II

• Perform the self-diagnosis for the multifunction switch (rear defogger switch). Refer to MULTIFUNCTION SWITCH SELF-DIAGNOSIS FUNCTION .

OK or NG? 

1. OK >> GO TO 6.
2. NG >> Refer to "REAR DEFOGGER SWITCH DOES NOT WORK  ".

• Connect the rear window defogger and door mirror defogger relay B8, and disconnect the BCM connector M4.
• Operate the rear defogger switch, and check the continuity between BCM harness connector M4 terminal 10(G/R) for the BCM and body ground.
  Fig 8: BCM Connector Terminal And Body Ground Continuity Specifications

  Courtesy of NISSAN MOTOR CO., U.S.A.
  Fig 9: Checking Multifunction Switch (Rear Defogger Switch) Signal

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

OK or NG? 

1. OK >> GO TO 7.
2. NG >> Repair or replace the harness between the BCM and display unit assembly.

• Turn the ignition switch OFF, and connect the BCM connector B4.
• Turn the ignition switch ON.
• Operate the rear defogger switch, and check the voltage between BCM connector B4 terminal 144(G/W) and body ground.
  Fig 10: BCM Connector Terminal And Body Ground Voltage Specifications

  Courtesy of NISSAN MOTOR CO., U.S.A.
  Fig 11: Checking Rear Defogger Output Signal

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

OK or NG? 

1. OK >> GO TO 8.
2. NG >> Replace the BCM.

• Turn the ignition switch OFF, and disconnect the BCM connector B4 and rear window defogger and door mirror defogger relay B8.
• Check continuity between BCM harness connector B4 terminal 144(G/W) and rear window defogger and door mirror defogger relay harness connector B8 terminal 2(G/W),and BCM harness connector B4 terminal 144(G/W) and body ground.
  Fig 12: BCM And Rear Window Defogger Connector Terminal And Body Ground Voltage Specifications

  Courtesy of NISSAN MOTOR CO., U.S.A.
  Fig 13: Checking Harness Continuity (Rear Window Defogger Control System) (1 Of 2)

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

OK or NG? 

1. OK >> GO TO 9.
2. NG >> Repair or replace harness.

• Disconnect the condenser connector B25.
• Check continuity between rear window defogger and door mirror defogger relay harness connector B8 terminal 7(L/R) and condenser harness connector B25 terminal 1(L/R),and between condenser harness connector B25 terminal 1 (L/R) and body ground.
  Fig 14: Rear Window And Door Mirror Defogger Relay Connector Terminal Continuity Specifications

  Courtesy of NISSAN MOTOR CO., U.S.A.
  Fig 15: Checking Harness Continuity (Rear Window Defogger Control System) (2 Of 2)

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

OK or NG? 

1. OK >> GO TO 10.
2. NG >> Repair or replace harness.

• Disconnect rear window defogger harness connector B421.
• Check the continuity between rear window defogger harness connector B421 and body ground.
  1. No. 1 (B) - body ground : Continuity should exist

OK or NG? 

1. OK >> Check filament. Refer to "FILAMENT CHECK  ".
   • If filament is OK, replace condenser.
   • If filament is NG, repair filament.
2. NG >> Repair or replace the rear window defogger ground harness.

Fig 16: Checking Rear Window Defogger Ground Harness

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