FixVault
Home › Toyota › 2009 › Avalon XLS › Repair and Diagnosis › Engine Performance › Engine Control System (2GR-FE) › SFI System › DTC U0101 Lost Communication with TCM › Inspection Procedure

Inspection Procedure

  1. CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC U0101) 
    1. Connect Techstream to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn the tester on.
    4. Enter the following menus: Powertrain/Engine/Trouble Codes.
    5. Read the DTCs.

      Result 

      DTC OUTPUT RESULT

      Display (DTC output) Proceed to
      U0101 A
      U0101 and other DTCs B

      B: GO TO DTC CHART 

      A: Go to next step 

  2. CHECK TCM TERMINAL VOLTAGE (+B AND E1 TERMINALS) 
    1. Disconnect the TCM connector.
    2. Turn the ignition switch to ON.
    3. Measure the voltage of the TCM connectors.

      Standard voltage 

      VOLTAGE SPECIFIED CONDITION

      Tester Connection Specified Condition
      B51-18 (+B) - B51-8 (E1) 9 to 14 V
    4. Turn the ignition switch off.
    5. Measure the resistance of the TCM connector.

      Standard resistance 

      RESISTANCE SPECIFIED CONDITIONS

      Tester Connection Specified Condition
      B51-8 (E1) - Body ground Below 1 Ω

      NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

      Fig 1: Identifying B51 TCM Connector Terminals
      G06227150Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Go to next step 

  3. CHECK HARNESS AND CONNECTOR 
    1. Disconnect the TCM connector.
    2. Disconnect the ECM connector.
    3. Measure the resistance of the wire harness side connectors.

      Standard resistance 

      RESISTANCE SPECIFIED CONDITIONS

      Tester Connection Specified Condition
      B51-6 (CAN+) - B50-2 (CAN+) Below 1 Ω
      B51-7 (CAN-) - B50-1 (CAN-) Below 1 Ω
      B51-6 (CAN+) or B50-2 (CAN+) - Body ground 1 MΩ or more
      B51-7 (CAN-) or B50-1 (CAN-) - Body ground 1 MΩ or more

      NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

      Fig 2: Identifying B50 TCM And B51 ECM Connector Terminals
      G06227151Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Go to next step 

  4. REPLACE ECM 
    1. Replace the ECM (See REMOVAL  ).
      NOTE: Replace the ECM with a ECM from a normally functioning vehicle of the same model.
  5. CHECK IF DTC RECURS 
    1. Connect Techstream to the DLC3.
    2. Clear the DTCs.
    3. Start the engine.
    4. Read the DTCs.

      Result 

      DTC OUTPUT RESULT

      Display (DTC Output) Proceed to
      U0101 A
      No DTC B

      B: REPLACE ECM (See  REMOVAL   ) 

      A: REPLACE TCM 

About FixVault