METER / GAUGE SYSTEM > Malfunction in Tachometer

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WIRING DIAGRAM


E108032E02


INSPECTION PROCEDURE

1.PERFORM ACTIVE TEST BY INTELLIGENT TESTER

  1. Operate the intelligent tester according to the display and select the "Active Test".

    Combination meter:

    Item
    		Test Details
    		Diagnostic Note
    TachoMeter Operation
    		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.



NG
REPLACE COMBINATION METER
OK


2.READ VALUE OF INTELLIGENT TESTER (ENGINE SPEED SIGNAL)

  1. Operate the intelligent tester according to the display and select the "Data List".

    Combination meter:

    Item
    		Measurement Item/Range (Display)
    		Normal Condition
    		Diagnostic Note
    Engine Rpm
    		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.



NG
Go to step 3
OK

REPLACE COMBINATION METER 

3.READ VALUE OF INTELLIGENT TESTER (ENGINE SPEED SIGNAL)

  1. Operate the intelligent tester according to the steps on the display and select the "Data List".

    ECM:

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



NG
GO TO ENGINE CONTROL SYSTEM
OK


4.INSPECT COMBINATION METER


    E107973E06

  1. Check the input signal waveform.

    1. Remove the combination meter with the connector still connected.

    2. Connect the oscilloscope to terminal L31-27 and body ground.

    3. Start the engine.



      4. E107976E02

    4. Check the signal waveform of the connector.
      Item
      		Condition
      Tool Setting
      		5 V/DIV., 10 msec./DIV.
      Vehicle Condition
      		Engine idle speed

      OK:
      As shown in the illustration



NG
REPLACE COMBINATION METER
OK


5.CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM)


    E108712E02

  1. Disconnect the A7 ECM connector.

  1. Disconnect the L31 meter connector.

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

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    L31-27 - A7-16
    		Always
    		Below 1 Ω
    L31-27 - Body ground
    		Always
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

REPLACE COMBINATION METER