Rear Window Defogger Switch Circuit Check

With CONSULT-II 

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

When rear window defogger switch is turned ON 

REAR DEF SW: ON 

When ignition switch is turned ON 

IGN ON SW: ON 

Fig 1: CONSULT-II Display - 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.
   VOLTAGE CHART
   
   

   Connector	Terminals		Condition	Voltage (V) (Approx.)
   	(+)	(-)
   M18	9	Ground	Rear window defogger switch is pressed.	0
   			Rear window defogger switch is OFF.	5

   Fig 2: Checking Voltage Between BCM Connector And Ground

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

OK or NG 

OK: Rear window defogger switch check is OK.

NG: GO TO 2.

1. Turn ignition switch OFF.
2. Disconnect BCM and unified meter and A/C amp.
3. Check continuity between BCM connector M18 terminal 9 and unified meter and A/C amp. connector M89 terminal 38.

   9 - 38: Continuity should exist. 

4. Check continuity between BCM connector M18 terminal 9 and ground

   9 - Ground: Continuity should not exist. 

Fig 3: Checking Continuity Between BCM Connector Terminal 9 And Unified Meter And A/C Amp. Terminal 38

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

OK or NG 

OK: GO TO 3.

NG: Repair or replace harness.

1. Connect BCM.
2. Turn ignition switch ON.
3. Check voltage between BCM connector M18 terminal 9 and ground.

   9 - Ground: Approx. 5V 

Fig 4: Checking Voltage Between BCM Connector M18 Terminal 9 And Ground

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

OK or NG 

OK: Replace unifed meter and A/C amp. Refer to "UNIFIED METER AND A/C AMP. ".

NG: Replace BCM. Refer to "BCM ".