2008 Lexus ES 350FACTORY OEM SERVICE PROCEDURE

Inspection Procedure

  1. INSPECT ECU TERMINAL VOLTAGE (+B TERMINAL) 
    1. Disconnect the TCM connector.
    2. Turn the engine switch on (IG).
    3. Measure the voltage according to the value (s) in the table below.

      Standard Voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      B40-18 (+B) - B40-8 (E1) Engine switch on (IG) 9 to 14 V
      Fig 1: Identifying TCM Connector B40 Terminals
      G05836154Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: CHECK FOR INTERMITTENT PROBLEMS 

    NG: Go to next step 

  2. CHECK HARNESS AND CONNECTOR (TCM - BODY GROUND) 
    1. Measure the resistance according to the value (s) in the table below.

      Standard Resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      B40-8 (E1) - Body ground Always Below 1 Ω
      Fig 2: Identifying TCM Connector B40 Terminals
      G05836155Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Reconnect the TCM connector.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (TCM - BODY GROUND) 

    OK: REPAIR OR REPLACE HARNESS OR CONNECTOR (TCM - EFI RELAY) 

Factory Service Tools

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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.