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Home › Toyota › 2004 › Matrix Base, 4WD › Repair and Diagnosis › External Pages › Different car › Section 603 (Defogger System - Diagnosis) › Rear Window Defogger Does Not Operate › Inspection Procedure

Inspection Procedure

WARNING: This page is about a different car, the 2002 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.
  1. USE LEXUS HAND-HELD TESTER 
    1. YES: Go to next step 
    2. NO: Go to step   3 
  2. DO ACTIVE TEST OF LEXUS HAND-HELD TESTER 
    1. ACTIVE TEST
      1. Make a judgement of good or bad and find out a malfunctioning part by the active test.

    Standard: 

    LUGGAGE ROOM J/B (LUGGAGE ROOM J/B ECU) 

    TESTER DISPLAY

    Item Operation
    Rr DEF OFF/ON
    1. OK: REPLACE LUGGAGE ROOM J/B, IF DEFOGGER DOES NOT OPERATE EVEN THOUGH A/C IS REPLACED 
    2. NG: Go to step 3 
  3. CHECK REAR WINDOW DEFOGGER 
    1. Check the continuity between terminals of the rear defogger connector.

    Standard: Continuity 

    NOTE:
    • With LEXUS hand-held tester, proceed to "OK-A".
    • Without LEXUS hand-held tester, proceed to "OK-B".
    1. OK-A: Go to next step 
    2. OK-B: Go to step   6 
    3. NG: REPAIR REAR WINDOW DEFOGGER 
  4. CHECK WIRE HARNESS (REAR WINDOW DEFOGGER - LUGGAGE ROOM J/B) 
    1. Disconnect the rear window defogger and luggage room J/B connectors.
    2. Check the continuity between the terminal of the rear window defogger vehicle's side connector and terminal 3 of the luggage room J/B vehicle's side connector. (See TERMINALS OF ECU )
      Fig 1: Identifying Terminals To Check Wiring Harness
      G03386891Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    Standard: Continuity 

    1. OK: GO TO NEXT STEP 
    2. NG: REPAIR OR REPLACE WIRE HARNESS OR CONNECTOR 
  5. CHECK WIRE HARNESS (REAR WINDOW DEFOGGER - BODY GROUND) 
    1. Check the continuity between terminal R21 - 1 and the body ground.
      Fig 2: Identifying Rear Window Defogger Terminal R21
      G03386892Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. OK: CHECK AND REPLACE AIR CONDITIONER AMPLIFIER ASSY 
    2. NG: REPAIR OR REPLACE WIRE HARNESS OR CONNECTOR 
  6. INSPECT DEFOGGER RELAY 
    1. Inspect the defogger relay continuity.
    Fig 3: Identifying Defogger Relay Terminals
    G03386893Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    Standard: 

    TESTER DISPLAY

    Condition Tester Connection Specified Condition
    Constant 1 -2 Continuity
    Apply B+ between terminals 1 and 2. 3 - 5 Continuity

    If the continuity is not as specified, replace the relay.

    1. OK: Go to next step 
    2. NG: REPLACE DEFOGGER RELAY 
  7. CHECK WIRE HARNESS (LUGGAGE ROOM J/B - BODY GROUND) 
    1. Remove the defogger relay.
    2. Check the voltage between each terminal of the luggage room J/B.

      Standard: 

      TESTER DISPLAY

      Terminal Tester Connection Specified Condition
      1 <=> Body Ground Ignition Switch ON 10 - 14 V
      5 <=> Body Ground Constant 10 - 14 V
    3. If terminal 1 malfunctions, proceed to "NG-A".
    4. If terminal 5 malfunctions, proceed to "NG-B".
      Fig 4: Identifying Luggage Room J/B Terminals
      G03386894Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG-A: REPLACE LUGGAGE ROOM JUNCTION BLOCK ASSY 
    2. NG-B: Go to step 8 
    3. OK: Go to next step 
  8. CHECK FUSE(DEFOG FUSE) 
    1. Remove the DEFOG fuse from the luggage room J/B.
    2. Check the continuity of the DEFOG fuse.
    1. OK: REPLACE LUGGAGE ROOM JUNCTION BLOCK ASSY 
    2. NG: REPLACE FUSE(DEFOG FUSE) 
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