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 window defogger switch is turned ON, a rear window defogger activation request signal is sent via the LIN communication line to the air conditioning amplifier. Then the air conditioning amplifier operates the rear window defogger.

WIRING DIAGRAM





INSPECTION PROCEDURE

HINT
This circuit uses the LIN communication line. Before performing the inspection, check that the LIN communication system is functioning normally Initial Inspection and Diagnostic Overview.

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM (DEFOGGER RELAY)

(a) Select the Active Test using the Techstream to generate a control command, and then check that the rear window defogger operates.

Air Conditioner





OK:

Rear window defogger operates normally.

NG -- INSPECT FUSE (DEFOG)
OK -- Continue to next step.

2. CHECK INTEGRATION CONTROL AND PANEL (OPERATION)

(a) Temporarily replace the integration control and panel with a new or normally functioning one.

(1) For Column Shift Type, refer to the following procedures Removal.

(2) For Floor Shift Type, refer to the following procedures Removal.

(b) Check that the malfunction disappears.

OK:

Malfunction disappears.

NG -- REPLACE AIR CONDITIONING AMPLIFIER Removal

OK -- END (INTEGRATION CONTROL AND PANEL IS DEFECTIVE)

3. INSPECT FUSE (DEFOG)

(a) Remove the DEFOG H-fuse from the engine room relay block.

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

Standard resistance:





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

4. INSPECT DEFOGGER RELAY (DEFOG)





(a) Remove the DEFOGGER relay from the engine room relay block.

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

Standard resistance:





NG -- REPLACE DEFOGGER RELAY
OK -- Continue to next step.

5. CHECK HARNESS AND CONNECTOR (DEFOGGER RELAY - BATTERY AND AIR CONDITIONING AMPLIFIER)





(a) Remove the DEFOGGER relay from the engine room relay block.

(b) Disconnect the J19 air conditioning amplifier connector.

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

Standard voltage:





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

Standard resistance:





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

6. CHECK HARNESS AND CONNECTOR (REAR WINDOW DEFOGGER - DEFOGGER RELAY AND BODY GROUND)





(a) Disconnect the P9 and P10 defogger connectors.

(b) Remove the DEFOGGER relay from the engine room relay block.

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

Standard resistance:





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

7. CHECK AIR CONDITIONING AMPLIFIER (OPERATION)

(a) Temporarily replace the air conditioning amplifier with a new or normally functioning one Removal.

(b) Check that the malfunction disappears.

OK:

Malfunction disappears.

NG -- REPAIR REAR WINDOW DEFOGGER Service and Repair

OK -- END (AIR CONDITIONING AMPLIFIER IS DEFECTIVE)