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Home >> Lexus >> 2008 >> ES 350 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - System & Component Testing, Removal, Inspection & Installation >> Active Control Engine Mount System >> DTC P16A3 TACH Signal Communication >> Inspection Procedure
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Inspection Procedure

  1. CHECK TERMINAL VOLTAGE (TACH TERMINAL) 
    1. Disconnect the A9 Active control engine mount ECU connector.
    2. Measure the voltage between the TACH terminal of the A9 Active control engine mount ECU connector and body ground.

      Standard 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Value
      TACH (A9-16) - Body ground Correct waveform is as shown
      Fig 1: Identifying Terminals Of A9 Active Control Engine Mount ECU Connector
      G05247908Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: REPLACE ACTIVE CONTROL ENGINE MOUNT ECU 

    NG: Go to next step. 

  2. CHECK HARNESS AND CONNECTOR (ACTIVE CONTROL ENGINE MOUNT ECU - ECM) 
    1. Disconnect the A9 active control engine mount (ACM) ECU connector and A10 ECM connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Value
      TACH (A9-16) - TACH (A10-15) Below 1 Ω
      Fig 2: Identifying Terminals Of A9 Active Control Engine Mount ECU And A10 ECM Connector
      G05247909Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPLACE ECM 

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