WINDOW DEFOGGER SYSTEM > Rear Window Defogger System does not Operate

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DESCRIPTION

When the defogger switch is turned ON, a rear defogger activation request signal is input to the multi-display. Then, the A/C amplifier assembly (A/C ECU) outputs this signal to the defogger relay (Marking: DEFOG) and the rear window defogger system is activated.

WIRING DIAGRAM


B106750E03


B106765E03


INSPECTION PROCEDURE

1.CHECK OPERATION

  1. Check that the engine starts normally.

    OK:
    Engine starts normally.



NG
GO TO ENTRY AND START SYSTEM
OK


2.PERFORM ACTIVE TEST BY INTELLIGENT TESTER (REAR WINDOW DEFOGGER)

  1. Using the intelligent tester Active Test, generate a control command and then check that the rear window defogger operates.

    A/C amplifier assembly (A/C ECU):

    Item
    		Test Details
    		Diagnostic Note
    Defogger Relay (Rear)
    		Operate rear window defogger OFF/ON
    		-


    Result:

    Result
    		Proceed to
    Rear window defogger operates normally
    		A
    Rear window defogger operates abnormally
    		B



B
Go to step 4
A


3.CHECK OPERATION OF MULTI-DISPLAY WITH NEW OR NORMALLY FUNCTIONING MULTI-DISPLAY

  1. Temporarily replace the multi-display with a new or normally functioning one.

  1. Check that the malfunction disappears.

    OK:
    Malfunction disappears.



NG
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
OK

REPLACE MULTI-DISPLAY 

4.INSPECT FUSE (DEFOG, ALT, LH J/B-AM, RH J/B-B, AM2, LH-IG)

  1. Remove the DEFOG, ALT, LH J/B-AM and RH J/B-B fuses from the engine room No. 1 relay block.

  1. Remove the AM2 fuse from the cowl side junction block RH.

  1. Remove the LH-IG fuse from the cowl side junction block LH.

  1. Measure the resistance of the fuses.

    Standard resistance:
    Below 1 Ω



NG
REPLACE FUSE
OK


5.INSPECT RELAY (Marking: DEFOG)
B106753E02

  1. Remove the DEFOG relay from the engine room No.1 relay block.

  1. Measure the resistance of the relay.

    Standard resistance:
    Tester Connection
    		Specified Condition
    3 - 4
    		Below 1 Ω
    3 - 5
    		10 kΩ or higher
    3 - 5
    		Below 1 Ω
    (when battery voltage is applied to terminals 1 and 2)



NG
REPLACE RELAY
OK


6.CHECK WIRE HARNESS (ENGINE ROOM NO. 1 RELAY BLOCK - ECM AND BATTERY)

B106798E02

  1. Remove the DEFOG relay from the engine room No. 1 relay block.

  1. Disconnect the A7 ECM connector.

  1. Measure the voltage of the wire harness side connectors.

    Standard voltage:
    Tester Connection
    		Condition
    		Specified Condition
    Relay block DEFOG relay terminal 1 - Body ground
    		Engine switch on (IG)
    		10 to 14 V
    R/B DEFOG relay terminal 5 - Body ground
    		Always
    		10 to 14 V

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    Relay block DEFOG relay terminal 2 - A7-13 (RDEF)
    		Always
    		Below 1 Ω



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


7.CHECK WIRE HARNESS (REAR WINDOW DEFOGGER - RELAY BLOCK AND BODY GROUND)

B106797E01

  1. Disconnect the W19 and V20 defogger connectors.

  1. Disconnect the DEFOG relay from the engine room No.1 relay block.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Specified Condition
    W19-1 - Relay block DEFOG relay terminal 3
    		Below 1 Ω
    V20-1 - Body ground
    		Below 1 Ω
    Relay block DEFOG relay terminal 4 - Body ground
    		Below 1 Ω



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


8.INSPECT REAR WINDOW DEFOGGER WIRE

  1. Turn the engine switch on (IG).

  1. Turn the defogger switch ON.



    B111142E01

  1. Check the voltage at the center of each defogger wire, as shown in the illustration.

    Standard voltage:
    Voltage
    		Criteria
    Approx. 5 V
    		Wire is not broken
    Approx. 10 or 0 V
    		Wire is broken

    HINT:
    If there is approximately 10 V, the wire may be faulty between the center of the wire and the wire end on the battery side. If there is no voltage, the wire may be faulty between the center of the wire and the wire end on the ground side.

    NOTICE:
    When measuring voltage, wrap a piece of tin foil around the tip of the negative tester probe and press the foil against the wire with your finger, as shown in the illustration.



    B106757E02

  1. Place the voltmeter's positive (+) lead against the defogger wire on the battery side.

  1. Place the voltmeter's negative (-) lead with the foil strip against the wire on the ground side.

  1. Slide the positive (+) lead from the battery side to the ground side.

  1. The point where the voltage drops from approximately 10 V to 0 V is where the defogger wire is broken.

    HINT:
    If the defogger wire is not broken, the voltmeter should indicate 0 V at the positive (+) end of the defogger wire but gradually increases to approximately 12 V as the meter probe is moved to the other end.



NG
REPAIR REAR WINDOW DEFOGGER WIRE
OK


9.CHECK OPERATION OF ECM WITH NEW OR NORMALLY FUNCTIONING ECM

  1. Temporarily replace the ECM with a new or normally functioning one.

  1. Check that the malfunction disappears.

    OK:
    Malfunction disappears.



NG
REPLACE A/C AMPLIFIER ASSEMBLY (A/C ECU)
OK

REPLACE ECM