Rear Window Defogger Switch

REAR WINDOW DEFOGGER SWITCH





Description
- The rear window defogger is operated by pressing the rear window defogger switch ON.
- The indicator lamp in the rear window defogger switch illuminates while the rear window defogger is ON.




Component Function Check
1. CHECK REAR WINDOW DEFOGGER SWITCH FUNCTION
1. Push ignition switch to ON.
2. Press rear window defogger switch.
3. Check that the indicator lamp of the rear window defogger switch illuminates.
4. Press rear window defogger switch.
5. Check that the indicator lamp of the rear window defogger switch extinguishes.
Is the inspection result normal?
YES - Rear window defogger switch function is OK.
NO - SEE Diagnosis Procedure.




Diagnosis Procedure
Regarding Wiring Diagram information, [1][2]Electrical Diagrams.
1.CHECK REAR WINDOW DEFOGGER RELAY OPERATION
1. Push the ignition switch to ON.
2. Check that an operation noise of rear window defogger relay [located in fuse block (J/B)] can be heard when pressing the rear window defogger switch ON and OFF.
Is the inspection result normal?
YES - GO TO 2
NO - GO TO 5
2.CHECK FUSE
Check if Fuse 13 from the rear window defogger relay output is blown.
Is the fuse blown?
YES - Replace the blown fuse after repairing the affected circuit.
NO - GO TO 3
3. CHECK FOR VOLTAGE FROM THE REAR WINDOW DEFOGGER RELAY
1. Connect a voltmeter between Fuse 13 and ground.
2. While pressing the rear window defogger switch ON and OFF, check for voltage between fuse block (J/B) connector M5 and ground.





Is the inspection result normal?
YES - GO TO 4
NO - Replace fuse block (J/B).
4.CHECK REAR WINDOW DEFOGGER SWITCH INDICATOR CIRCUIT
1. Press rear window defogger switch.
2. Check for voltage between controller (auto amp.) connector M37 terminal 22 and ground.










Is the inspection result normal?
YES - Replace controller (auto amp.). Service and Repair, "Removal and Installation".
NO - Repair or replace harness.
5.CHECK CONTROLLER (AUTO AMP.) FUNCTION
CONSULT-III
1. Select BCM (REAR DEFOGGER) DATA MONITOR.
2. While pressing and releasing the rear window defogger switch, check that the switch state changes between ON and OFF.





Is the inspection result normal?
YES - GO TO 8
NO - GO TO 6
6. CHECK REAR WINDOW DEFOGGER ON SIGNAL CIRCUIT
Check voltage between BCM connector M18 terminal 38 and ground.





Is the inspection result normal?
YES - Replace BCM. Service and Repair.
NO - GO TO 7
7. CHECK HARNESS CONTINUITY
1. Push ignition switch to OFF.
2. Disconnect BCM and controller (auto amp.).
3. Check continuity between BCM connector M18 terminal 38 and controller (auto amp.) connector M37 terminal 23 connector.





4. Check continuity between BCM harness connector M18 terminal 38 and ground.





Is the inspection result normal?
YES - Replace controller (auto amp.). Service and Repair.
NO - Repair or replace harness.
8. CHECK REAR WINDOW DEFOGGER RELAY GROUND CIRCUIT
CONSULT-III
1. Select BCM (REAR DEFOGGER) ACTIVE TEST.
2. Turn REAR DEFOGGER active test ON and OFF.
3. Check voltage between fuse block (J/B) connector M4 terminal 4Q and ground.










Is the inspection result normal?
YES - Check intermittent incident. Intermittent Incident.
NO - GO TO 9
9. CHECK HARNESS CONTINUITY
1. Turn ignition switch OFF.
2. Disconnect BCM and fuse block (J/B).
3. Check continuity between BCM connector M18 terminal 59 and fuse block (J/B) connector M4 terminal
4Q.





4. Check continuity between fuse block (J/B) connector M4 terminal 4Q and ground.





Is the inspection result normal?
YES - GO TO 10
NO - Repair or replace harness.
10. CHECK REAR WINDOW DEFOGGER RELAY GROUND CIRCUIT
1. Connect fuse block (J/B) all connectors.
2. Push ignition switch to ON.
3. Check voltage between fuse block (J/B) connector M4 terminal 4Q and ground.





Is the inspection result normal?
YES - GO TO 11
NO - Replace fuse block (J/B).
11. CHECK REAR WINDOW DEFOGGER RELAY GROUND CIRCUIT
Check voltage between fuse block (J/B) connector M4 terminal 4Q and ground.





Is the inspection result normal?
YES - Check intermittent incident. Intermittent Incident.
NO - Replace BCM. Service and Repair.