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Home >> Toyota >> 2005 >> Avalon Touring >> Repair and Diagnosis >> Electrical >> Gauges >> Combination Meter >> Malfunction In Tachometer >> Inspection Procedure

Inspection Procedure

  1. PERFORM ACTIVE TEST USING HAND-HELD TESTER 
    1. Operate the hand-held tester according to the steps on the display and select the "ACTIVE TEST".

      METER: 

      DIAGNOSTIC NOTE

      Item Test Details Diagnostic Note
      TACHOMETER 0 rpm / 1,000 rpm / 2,000 rpm / 3,000 rpm / 4,000 rpm / 5,000 rpm / 6,000 rpm / 7,000 rpm -

      OK: 

      Needle indication is normal. 

    1. NG : REPLACE COMBINATION METER ASSY (SEE  OVERHAUL  ) 
    2. OK : Go to next step. 
  2. READ VALUE OF HAND-HELD TESTER (ENGINE SPEED SIGNAL) 
    1. Operate the hand-held tester according to the steps on the display and select the "DATA LIST".

      METER: 

      DIAGNOSTIC NOTE

      Item Measurement Item/Range (Display) Normal Condition Diagnostic Note
      TACHO METER Engine speed / Min.: 0 rpm, Max.: 12,750 rpm Almost same as actual engine speed (When engine is running) -

      OK: 

      Engine speed displayed on the tester is almost the same as the actual engine speed. 

    1. NG : Go to step 3 
    2. OK : REPLACE COMBINATION METER ASSY (SEE  OVERHAUL  ) 
  3. READ VALUE OF HAND-HELD TESTER (ENGINE SPEED SIGNAL) 
    1. Operate the hand-held tester according to the steps on the display and select the "DATA LIST".

      ENGINE: 

      DIAGNOSTIC NOTE

      Item Measurement Item/Range (Display) Normal Condition Diagnostic Note
      ENGINE SPD Engine speed / Min.: 0 rpm, Max.: 16,383 rpm Almost same as actual engine speed (When engine is running) -

      OK: 

      Engine speed displayed on the tester is almost the same as the actual engine speed. 

    1. NG : GO TO ENGINE CONTROL SYSTEM (SEE  PROBLEM SYMPTOMS TABLE  ) 
    2. OK : Go to next step. 
  4. INSPECT COMBINATION METER ASSY 

    INSPECTION USING AN OSCILLOSCOPE 

    1. Check the input signal wave form.
      1. Disconnect the E2 connector.
      2. Remove the combination meter assy.
      3. Connect the oscilloscope to the terminals E2-14 (TACHO) and body ground.
      4. Start the engine.
        Fig 1: Inspecting Combination Meter Assy
        G02975625Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      5. Check the signal wave form according to the condition (s) in the table below.
        SIGNAL WAVE FORM CONDITION

        Item Condition
        Tool setting 5 V/DIV., 10 ms/DIV.
        Vehicle condition Engine idle speed

        OK: 

        The wave form is displayed as shown in the illustration. 

        Fig 2: Oscilloscope Waveform Signal Graph
        G02975626Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG : Go to step 5 
    2. OK : REPLACE COMBINATION METER ASSY (SEE  OVERHAUL  ) 
  5. CHECK HARNESS AND CONNECTOR (BETWEEN ECM AND COMBINATION METER ASSY) 
    1. Disconnect the E2 and D41 connectors.
    2. Measure the resistance according to the value (s) in the table below.

      Standard: 

      SPECIFIED CONDITION

      Tester Connection Condition Specified Condition
      E2-14 (TACHO) - D41-1 (TACH) Always Below 1 Ω
      E2-14 (TACHO) - Body ground Always 10 kΩ or higher
      Fig 3: Checking Harness & Connector (Between ECM & Combination Meter Assy)
      G02975627Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 
    2. OK : GO TO ENGINE CONTROL SYSTEM (SEE  PROBLEM SYMPTOMS TABLE  ) 
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