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HOMESERVICE MANUALSTOYOTA2004MATRIX XR, FWD, STANDARDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 605 (MULTIPLEX COMMUNICATION SYSTEM - DIAGNOSIS)DTC B1278: COMBINATION SWITCH ECU COMMUNICATION STOPINSPECTION PROCEDURE
2004 Toyota Matrix XR, FWD, Standard

Inspection Procedure

2004 Toyota Matrix XR, FWD, StandardSECTION 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. CHECK CONTINUITY OF COMMUNICATION LINE 
    1. Check the wire harness among the combination SW and tilt and telescopic ECU and luggage room J/B.
      Fig 1: Identifying Combination SW & Tilt & Telescopic ECU & Luggage Room J/B
      G03387152Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Disconnect the connectors of the combination SW, tilt and telescopic ECU and luggage room J/B.
      2. Check the continuity between terminal C9-10 (MPX2) of the combination SW vehicle's side connector and terminal L24-2 (MPX+) of the luggage room J/B vehicle's side connector.

        Standard: Continuity 

      3. Check the continuity between terminal C9-9 (MPX1) of the combination SW vehicle's side connector and terminal 6 (MPX2) of the tilt and telescopic ECU vehicle's side connector.

        Standard: Continuity 

    1. NG: REPAIR OR REPLACE WIRE HARNESS OR CONNECTOR 
    2. OK: Go to next step 
  2. CHECK TURN SIGNAL SWITCH ASSY 
    1. Inspect the SW power source input.
      1. Disconnect the SW connector C9.
      2. Check the voltage between each terminal of the SW vehicle's side connector.
      Fig 2: Identifying SW Connector C9
      G03387153Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    Standard: 

    SPECIFIED CONDITION

    Tester connection Condition Specified condition
    C9-1 (B) - Body ground Constant 10 - 14 V
    1. NG: REPAIR OR REPLACE FUSE OR WIRE HARNESS AND CONNECTOR 
    2. OK: Go to next step 
  3. CHECK TURN SIGNAL SWITCH ASSY 
    1. Inspect the SW body ground.
      1. Disconnect the SW connector C9.
      2. Check the continuity between terminal 8 (E) of the SW and the body ground.

      Standard: Continuity 

      Fig 3: Identifying Turn Signal Switch
      G03387154Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: REPAIR OR REPLACE WIRE HARNESS OR CONNECTOR 
    2. OK: REPLACE TURN SIGNAL SWITCH ASSY 
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.