Rear Window Defogger System Does Not Operate

WINDSHIELD / WINDOWGLASS: WINDOW DEFOGGER SYSTEM: Rear Window Defogger System does not Operate
- Rear Window Defogger System does not Operate

DESCRIPTION

When the rear defogger switch, which is built into the heater control, is operated, the operation signals are transmitted to the DEF relay (coil side). When the DEF relay (coil side) receives the signals, it turns on the DEF relay (switch side) to operate the rear window defogger.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT FUSES (DEF, GAUGE, A/C)





(a) Remove the DEF, GAUGE and A/C fuses from the main body ECU.

(b) Measure the resistance according to the value(s) in the table below.

Standard resistance:





(c) Reinstall the fuses.

NG -- REPLACE FUSE
OK -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (REAR WINDOW DEFOGGER WIRE BATTERY POSITIVE)





(a) Measure the voltage according to the value(s) in the table below.

Standard voltage:





NG -- CHECK HARNESS AND CONNECTOR (REAR WINDOW DEFOGGER WIRE - MAIN BODY ECU)
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (REAR WINDOW DEFOGGER WIRE CONNECTOR - BODY GROUND)





(a) Disconnect the O8 rear window defogger wire connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard resistance:





(c) Reconnect the rear window defogger wire connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPAIR REAR WINDOW DEFOGGER WIRE

4. CHECK HARNESS AND CONNECTOR (REAR WINDOW DEFOGGER WIRE - MAIN BODY ECU)





(a) Disconnect the 4F main body ECU connector.

(b) Disconnect the N2 rear window defogger wire connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard resistance:





(d) Reconnect the main body ECU connector.

(e) Reconnect the rear window defogger connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

5. CHECK HARNESS AND CONNECTOR (REAR WINDOW DEFOGGER SYSTEM POWER SOURCE)

(a) Disconnect the 4G main body ECU connector.





(b) Measure the voltage according to the value(s) in the table below.

Standard voltage:





(c) Reconnect the main body ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

6. INSPECT MAIN BODY ECU (DEF RELAY)





(a) Remove the main body ECU.

(b) Remove the GAUGE fuse from the main body ECU.

(c) Measure the resistance of the DEF relay.

Standard resistance:





(d) Reinstall the fuse.

(e) Reinstall the main body ECU.

NG -- REPLACE MAIN BODY ECU
OK -- Continue to next step.

7. CHECK HARNESS AND CONNECTOR (REAR WINDOW DEFOGGER SWITCH - MAIN BODY ECU)

(a) Disconnect the G6 heater control connector.





(b) Disconnect the 4Q, 4S main body ECU connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard resistance:





(d) Reconnect the heater control connector.

(e) Reconnect the main body ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

8. CHECK HARNESS AND CONNECTOR (HEATER CONTROL - BODY GROUND)

(a) Measure the resistance according to the value(s) in the table below.





Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE HEATER CONTROL Disassembly