Rear Window Defogger Switch Circuit Check

With CONSULT-II 

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

Fig 1: CONSULT-II Display - REAR DEF SW, IGN ON SW

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

When rear window defogger switch is turned to ON 

REAR DEF SW: ON 

When ignition switch is turned to ON 

IGN ON SW: ON 

Without CONSULT-II 

1. Turn ignition switch ON.
2. Check voltage between BCM connector ground.
   Fig 2: Checking Rear Window Defogger Switch Operation

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

   Connector	Terminal (Wire color)		Condition	Voltage (V) (Approx.)
   	(+)	(-)
   M3	9(L/W)	Ground	Rear window defogger switch is pressed.	0
   			Rear window defogger switch is OFF.	5

OK or NG

1. OK: Rear window defogger switch is OK.
2. NG: GO TO 2.

1. Turn ignition switch OFF.
2. Disconnect BCM and A/C and AV switch connector.
3. Check continuity between BCM connector M3 terminal 9 and A/C and AV switch connector M64 terminal 16.
   Fig 3: Checking Rear Window Defogger Switch Harness Continuity

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

   9 (L/W) - 16 (L/W): Continuity should exist. 

   OK or NG

1. OK: GO TO 3.
2. NG: Repair or replace harness between BCM and A/C and AV switch.

1. Connect BCM connector.
2. Turn ignition switch ON.
3. Check voltage between BCM connector M3 terminal 9 and ground.
   Fig 4: Checking BCM Output Signal

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

   9 (L/W) - Ground: Approx. 5 

   OK or NG

1. OK: Replace A/C and AV switch.
2. NG: Replace BCM.