LEMON Manuals: Even more car manuals for everyone: 1960-2025
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 >> ECU Power Source Circuit >> Inspection Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Inspection Procedure

  1. INSPECT ECU TERMINAL VOLTAGE (+B AND IG2 TERMINAL) 
    1. Measure the voltage according to the value(s) in the table below.

      Standard Voltage 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Condition Specified Value
      +B (A9-2) - Body ground Always 10 to 14 V
      1G2 (A9-10) - GND (A9-12) Engine switch on (IG) 10 to 14 V
      Fig 1: >Identifying Terminals Of A9 Active Control Engine
      G05835622Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: CHECK FOR INTERMITTENT PROBLEMS 

    NG: Go to next step. 

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

      Standard Resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      GND (A9-12) - Body ground Below 1 Ω
      Fig 2: Identifying Terminals Of A9 Active Control Engine Mount ECU Connector
      G05247906Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Reconnect the active control engine mount ECU connector.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (ACTIVE CONTROL ENGINE MOUNT ECU - BODY GROUND) 

    OK: REPAIR OR REPLACE HARNESS OR CONNECTOR (ACTIVE CONTROL ENGINE MOUNT ECU - BATTERY)