Diagnosis Procedure

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.





REAR WINDOW DEFOGGER SWITCH


Diagnosis Procedure

Regarding Wiring Diagram information, 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 13 and ground.





Is the inspection result normal?
YES - GO TO 4
NO - GO TO 11
4.CHECK REAR WINDOW DEFOGGER SWITCH INDICATOR CIRCUIT
1. Press rear window defogger switch.
2. Check for voltage between front air control connector M37 terminal 22 and ground.










Is the inspection result normal?
YES - Replace front air control. Service and Repair.
NO - Repair or replace harness.
5.CHECK FRONT AIR CONTROL (REAR WINDOW DEFOGGER SWITCH) 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. Body Control System.
NO - GO TO 7
7. CHECK HARNESS CONTINUITY
1. Push ignition switch to OFF.
2. Disconnect BCM and front air control.
3. Check continuity between BCM connector M18 terminal 38 and front air control M37 terminal 23 connector.





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





Is the inspection result normal?
YES - Replace front air control. 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 - GO TO 12
NO - GO TO 9
9. CHECK REAR WINDOW DEFOGGER RELAY CIRCUIT
CONSULT-III
1. Select BCM (REAR DEFOGGER) ACTIVE TEST.
2. Turn REAR DEFOGGER active test OFF.

REAR DEFOGGER : OFF

3. Push ignition switch ON and OFF.





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





Is the inspection result normal?
YES - GO TO 10
NO - GO TO 11
10. CHECK HARNESS CONTINUITY
1. Push ignition switch to 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.





Is the inspection result normal?
YES - Replace BCM. Body Control System.
NO - Repair or replace harness.
11. CHECK HARNESS CONTINUITY
1. Push ignition switch to OFF.
2. Disconnect BCM and fuse block (J/B).
3. Check continuity between fuse block (J/B) connector M4 terminal 4Q and ground.





Is the inspection result normal?
YES - GO TO 12.
NO - Repair or replace harness.
12. CHECK REAR WINDOW DEFOGGER RELAY
Check rear window defogger relay. Component Inspection.
Is the inspection result normal?
YES - GO TO 13
NO - Replace rear window defogger relay.
13. CHECK INTERMITTENT INCIDENT
Check intermittent incident. Intermittent Incident.
Is the inspection result normal?
YES - Check the following.
- Battery power supply circuit.
- Fuse block (J/B).
NO - Repair or replace the malfunctioning parts.