Circuit Inspection

2004 Toyota Matrix XR, FWD, StandardSECTION Circuit Inspection
WARNING: This page is about a different car, the 2002 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.

  1. CHECK THE COMMUNICATION BETWEEN THE COMBINATION METER & THE MULTIPLEX COMMUNICATION CIRCUIT

    INSPECTION PROCEDURE

    1. Inspect indicator. 

      Check:  Turn ON and OFF the switch corresponding to the following indicators and check if the indicator lights up or goes off accordingly.

      • Door indicator (Open/close operation of any of doors)
      • Brake indicator (ON/OFF operation of the parking brake)
      • Seat belt indicator (ON/OFF operation of the buckle switch)
      1. Yes:  Normal communication.
      2. No: Go to   2 . 
    2. Any of them do not light. 
      1. NO:  Go to  3.
      2. Yes:  Flow chart No.  5.
    3. All of them do not light. 

      Communication error. Wire harness faulty. 

  2. WHOLE METER DOES NOT FUNCTION

    INSPECTION PROCEDURE

    1. Check the meter operation. 

      Check:  With the ignition switch ON, nothing is displayed.

    2. Check the positive terminal of IG. 

      CHECK:  if the fuse (GAUGE 10A) is normal or not. Turn the ignition switch ON and check that a voltage of 10 - 14 V is applied between the meter connector terminal A22 (IG+) and the body ground.

      1. Yes:  Go to  3.
      2. No:  Fuse faulty. Wire harness faulty.
    3. Check the grounding. 

      Check:  Disconnect the meter connector and check that there is continuity between terminal A15/A14 on the vehicle side connector and the body ground.

      1. Yes:  Improper connection of the meter connector. Communication meter ECU faulty.
      2. No:  Body ground faulty. Wire harness faulty.
  3. MARGIN OF ERROR IN SPEEDOMETER IS LARGE, OR IT REMAINS AS 0 KM/H

    INSPECTION PROCEDURE

    1. Check the brake ECU. 

      CHECK:

      1. Perform a diagnosis check of the brake system.
      2. Proceed to next Circuit inspection shown in problem symptoms table. See TROUBLE SHOOTING .
      1. No:  Go to  2.
      2. Yes:  Replace brake ECU.
    2. Check the vehicle speed signal input. 

      Preparation:  Turn the ignition switch ON.

      CHECK:  Disconnect the meter connector, drive the vehicle at a speed of 2 - 4 km/h and check that continuity between terminal A9 on the vehicle side connector and the body ground is repeatedly turned ON and OFF.

      1. Yes:  Combination meter ECU faulty.
      2. No:  Wire harness faulty. Speed output terminal in brake ECU faulty.
  4. FUEL RECEIVER GAUGE IS INOPERATIVE OR IMPROPER

    INSPECTION PROCEDURE

    1. Fuel gauge diagnosis check  . See Fuel gauge .
    2. Reset inclination sensor  . See RESET INCLINATION SENSOR .
    3. Fuel sender gauge check  . See STEP 1 - INSPECT COMBINATION METER CIRCUIT .
      1. NG:  Replace fuel tank.
      2. OK:  Go to  4.
    4. Multiplex communication Circuit check  . See HOW TO PROCEED WITH TROUBLESHOOTING MULTIPLEX COMMUNICATION SYSTEM .

      CHECK:  if the communication between the combination meter and the multiplex communication Circuit is normal or not.

      1. No:  Multiplex communication Circuit error. Wire harness faulty.
      2. Yes:  Go to  5.
    5. Check the body ECU. 

      CHECK:  with the fuel sender gauge connector connected, check if the voltage between each of terminal 1 (FV), 5 (FR) and 6 (FE) of the vehicle side wire harness and connector and the body ground is normal or not.

      Fig 1: Identifying Fuel Sender Gauge Terminals
      G01112630Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
RENDER: 1.0x

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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.