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ECU Power Source Circuit [11/2021 - ]: Procedure

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  1. CHECK HARNESS AND CONNECTOR (BATT TERMINAL VOLTAGE) 
    1. Measure the voltage according to the value(s) in the table below.
      GTY1065077Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Transmission Floor Shift Assembly (Shift Control ECU))

      Standard Voltage

      Tester Connection Condition Specified Condition
      D39-2 (BATT) - Body ground Ignition switch off 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  7

    Result: 

    OK 

    See step  2

  2. CHECK HARNESS AND CONNECTOR (IGCT, IGP TERMINAL VOLTAGE) 
    1. Turn the ignition switch to ON.
    2. Measure the voltage according to the value(s) in the table below.
      GTY1065076Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Transmission Floor Shift Assembly (Shift Control ECU))

      Standard Voltage

      Tester Connection Condition Specified Condition
      D39-3 (IGCT) - Body ground Ignition switch ON 11 to 14 V
      D39-1 (IGP) - Body ground Ignition switch ON 11 to 14 V
    3. Turn the Ignition switch off.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  8

    Result: 

    OK 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (SHIFT CONTROL ECU - BODY GROUND) 
    1. Disconnect the D39 transmission floor shift assembly (shift control ECU) connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      D39-9 (E1) - Body ground Always Below 1 Ω
      D39-23 (E12) - Body ground Always Below 1 Ω
    3. Reconnect the transmission floor shift assembly (shift control ECU) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (SHIFT CONTROL ECU - BODY GROUND) 

    Result: 

    OK 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (MA1, BAT1 TERMINAL VOLTAGE) 
    1. Disconnect the B77 and B78 shift control actuator assembly (shift actuator ECU) connectors.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      B77-1 (MA1) - Body ground Ignition switch off 11 to 14 V
      B78-8 (BAT1) - Body ground Ignition switch off 11 to 14 V
    3. Reconnect the shift control actuator assembly (shift actuator ECU) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  9

    Result: 

    OK 

    See step  5

  5. CHECK HARNESS AND CONNECTOR (IGCT TERMINAL VOLTAGE) 
    1. Disconnect the B77 shift control actuator assembly (shift actuator ECU) connector.
    2. Turn the ignition switch to ON.
      NOTE:

      If the ignition switch is turned to ON with the connector disconnected, other DTCs will be stored. Be sure to clear the DTCs after the inspection.

    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      B77-5 (IGCT) - Body ground Ignition switch ON 11 to 14 V
    4. Turn the Ignition switch off.
    5. Reconnect the shift control actuator assembly (shift actuator ECU) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IGCT RELAY CIRCUIT) 

    Result: 

    OK 

    See step  6

  6. CHECK HARNESS AND CONNECTOR (SHIFT ACTUATOR ECU - BODY GROUND) 
    1. Disconnect the B77 shift control actuator assembly (shift actuator ECU) connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      B77-2 (E01) - Body ground Always Below 1 Ω
      B77-7 (E02) - Body ground Always Below 1 Ω
    3. Reconnect the shift control actuator assembly (shift actuator ECU) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    GO TO PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [11/2021 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (SHIFT ACTUATOR ECU - BODY GROUND) 

  7. CHECK HARNESS AND CONNECTOR (SHIFT CONTROL ECU - NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY) 
    1. Remove the P COM MAIN fuse from the No. 1 engine room relay block and No. 1 junction block assembly.
    2. Disconnect the B78 shift control actuator assembly (shift actuator ECU) connector.
    3. Disconnect the D39 transmission floor shift assembly (shift control ECU) connector.
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      D39-2 (BATT) - 2 (P CON MAIN fuse holder) Always Below 1 Ω
      D39-2 (BATT) or 2 (P CON MAIN fuse holder) - Body ground and other terminals Always 10 kΩ or higher
    5. Reconnect the transmission floor shift assembly (shift control ECU) connector.
    6. Reconnect the shift control actuator assembly (shift actuator ECU) connector.
    7. Install the P COM MAIN fuse.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (AUXILIARY BATTERY - NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY) 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (SHIFT CONTROL ECU - NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY) 

  8. CHECK HARNESS AND CONNECTOR (SHIFT CONTROL ECU - NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY) 
    1. Remove the IGCT NO. 3 fuse from the No. 1 engine room relay block and No. 1 junction block assembly.
    2. Remove the ECU-IGP NO. 3 fuse from the No. 1 engine room relay block and No. 1 junction block assembly.
    3. Disconnect the B77 shift control actuator assembly (shift actuator ECU) connector.
    4. Disconnect the D39 transmission floor shift assembly (shift control ECU) connector.
    5. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      D39-3 (IGCT) - 2 (IGCT NO. 3 fuse holder) Always Below 1 Ω
      D39-1 (IGP) - 2 (ECU-IGP NO. 3 fuse holder) Always Below 1 Ω
      D39-3 (IGCT) or 2 (IGCT NO. 3 fuse holder) - Body ground and other terminals Always 10 kΩ or higher
      D39-1 (IGP) or 2 (ECU-IGP NO. 3 fuse holder) - Body ground and other terminals Always 10 kΩ or higher
    6. Reconnect the transmission floor shift assembly (shift control ECU) connector.
    7. Reconnect the shift control actuator assembly (shift actuator ECU) connector.
    8. Install the ECU-IGP NO. 3 fuse.
    9. Install the IGCT NO. 3 fuse.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IGCT RELAY POWER SUPPLY, IGP NO. 1 RELAY POWER SUPPLY) 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (SHIFT CONTROL ECU - NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY) 

  9. CHECK HARNESS AND CONNECTOR (SHIFT ACTUATOR ECU - NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY) 
    1. Remove the P CON MTR fuse from the No. 1 engine room relay block and No. 1 junction block assembly.
    2. Remove the P COM MAIN fuse from the No. 1 engine room relay block and No. 1 junction block assembly.
    3. Disconnect the D39 transmission floor shift assembly (shift control ECU) connector.
    4. Disconnect the B77 and B78 shift control actuator assembly (shift actuator ECU) connectors.
    5. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      B77-1 (MA1) - 2 (P CON MTR fuse holder) Always Below 1 Ω
      B78-8 (BAT1) - 2 (P COM MAIN fuse holder) Always Below 1 Ω
      B77-1 (MA1) or 2 (P CON MTR fuse holder) - Body ground and other terminals Always 10 kΩ or higher
      B78-8 (BAT1) or 2 (P COM MAIN fuse holder) - Body ground and other terminals Always 10 kΩ or higher
    6. Reconnect the shift control actuator assembly (shift actuator ECU) connector.
    7. Reconnect the transmission floor shift assembly (shift control ECU) connector.
    8. Install the P COM MAIN fuse.
    9. Install the P CON MTR fuse.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (AUXILIARY BATTERY - NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY) 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (SHIFT ACTUATOR ECU - NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY) 

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