Rear Window Defogger Switch Circuit Check

With CONSULT-III 

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

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-III 

1. Turn ignition switch ON.
2. Check voltage between BCM connector ground.
   TERMINAL VOLTAGE REFERENCE 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 1: Checking Voltage Between BCM Connector Terminal 9 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 front air control.
3. Check continuity between BCM connector M18 (A) terminal 9 and front air control connector M49 (B) terminal 16.

   9 - 16 : Continuity should exist. 

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

   9 - Ground : Continuity should not exist. 

OK or NG 

OK: GO TO 3.

NG: Repair or replace harness.

Fig 2: Checking Continuity Between BCM Connector M18 (A) Terminal 9 And Front Air Control Connector M49 (B) Terminal 16, And Between Connector M18 Terminal 9 And Ground

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

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

   9 - Ground : Approx. 5V 

OK or NG 

OK: Replace front air control. Refer to "CONTROL UNIT ".

NG: Replace BCM. Refer to "REMOVAL AND INSTALLATION OF BCM ".

Fig 3: Checking Voltage Between BCM Connector M18 Terminal 9 And Ground

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